Document RESTful services by combining hand-written documentation with auto-generated snippets produced with Spring MVC Test or WebTestClient.

Introduction

The aim of Spring REST Docs is to help you produce accurate and readable documentation for your RESTful services.

Writing high-quality documentation is difficult. One way to ease that difficulty is to use tools that are well-suited to the job. To this end, Spring REST Docs uses Asciidoctor by default. Asciidoctor processes plain text and produces HTML, styled and laid out to suit your needs. If you prefer, you can also configure Spring REST Docs to use Markdown.

Spring REST Docs uses snippets produced by tests written with Spring MVC’s test framework, Spring WebFlux’s WebTestClient or REST Assured 5. This test-driven approach helps to guarantee the accuracy of your service’s documentation. If a snippet is incorrect, the test that produces it fails.

Documenting a RESTful service is largely about describing its resources. Two key parts of each resource’s description are the details of the HTTP requests that it consumes and the HTTP responses that it produces. Spring REST Docs lets you work with these resources and the HTTP requests and responses, shielding your documentation from the inner-details of your service’s implementation. This separation helps you document your service’s API rather than its implementation. It also frees you to evolve the implementation without having to rework the documentation.

Getting started

This section describes how to get started with Spring REST Docs.

Sample Applications

If you want to jump straight in, a number of sample applications are available:

Table 1. MockMvc
Sample Build system Description

Spring Data REST

Maven

Demonstrates the creation of a getting started guide and an API guide for a service implemented by using Spring Data REST.

Spring HATEOAS

Gradle

Demonstrates the creation of a getting started guide and an API guide for a service implemented by using Spring HATEOAS.
Table 2. WebTestClient
Sample Build system Description

WebTestClient

Gradle

Demonstrates the use of Spring REST docs with Spring WebFlux’s WebTestClient.
Table 3. REST Assured
Sample Build system Description

REST Assured

Gradle

Demonstrates the use of Spring REST Docs with REST Assured.
Table 4. Advanced
Sample Build system Description

Slate

Gradle

Demonstrates the use of Spring REST Docs with Markdown and Slate.

TestNG

Gradle

Demonstrates the use of Spring REST Docs with TestNG.

JUnit 5

Gradle

Demonstrates the use of Spring REST Docs with JUnit 5.

Requirements

Spring REST Docs has the following minimum requirements:

  • Java 17

  • Spring Framework 6

Additionally, the spring-restdocs-restassured module requires REST Assured 5.1.

Build configuration

The first step in using Spring REST Docs is to configure your project’s build. The Spring HATEOAS and Spring Data REST samples contain a build.gradle and pom.xml, respectively, that you may wish to use as a reference. The key parts of the configuration are described in the following listings:

Maven
<dependency> (1)
	<groupId>org.springframework.restdocs</groupId>
	<artifactId>spring-restdocs-mockmvc</artifactId>
	<version>{project-version}</version>
	<scope>test</scope>
</dependency>

<build>
	<plugins>
		<plugin> (2)
			<groupId>org.asciidoctor</groupId>
			<artifactId>asciidoctor-maven-plugin</artifactId>
			<version>2.2.1</version>
			<executions>
				<execution>
					<id>generate-docs</id>
					<phase>prepare-package</phase> (3)
					<goals>
						<goal>process-asciidoc</goal>
					</goals>
					<configuration>
						<backend>html</backend>
						<doctype>book</doctype>
					</configuration>
				</execution>
			</executions>
			<dependencies>
				<dependency> (4)
					<groupId>org.springframework.restdocs</groupId>
					<artifactId>spring-restdocs-asciidoctor</artifactId>
					<version>{project-version}</version>
				</dependency>
			</dependencies>
		</plugin>
	</plugins>
</build>
1 Add a dependency on spring-restdocs-mockmvc in the test scope. If you want to use WebTestClient or REST Assured rather than MockMvc, add a dependency on spring-restdocs-webtestclient or spring-restdocs-restassured respectively instead.
2 Add the Asciidoctor plugin.
3 Using prepare-package allows the documentation to be included in the package.
4 Add spring-restdocs-asciidoctor as a dependency of the Asciidoctor plugin. This will automatically configure the snippets attribute for use in your .adoc files to point to target/generated-snippets. It will also allow you to use the operation block macro.
Gradle
plugins { (1)
	id "org.asciidoctor.jvm.convert" version "3.3.2"
}

configurations {
	asciidoctorExt (2)
}

dependencies {
	asciidoctorExt 'org.springframework.restdocs:spring-restdocs-asciidoctor:{project-version}' (3)
	testImplementation 'org.springframework.restdocs:spring-restdocs-mockmvc:{project-version}' (4)
}

ext { (5)
	snippetsDir = file('build/generated-snippets')
}

test { (6)
	outputs.dir snippetsDir
}

asciidoctor { (7)
	inputs.dir snippetsDir (8)
	configurations 'asciidoctorExt' (9)
	dependsOn test (10)
}
1 Apply the Asciidoctor plugin.
2 Declare the asciidoctorExt configuration for dependencies that extend Asciidoctor.
3 Add a dependency on spring-restdocs-asciidoctor in the asciidoctorExt configuration. This will automatically configure the snippets attribute for use in your .adoc files to point to build/generated-snippets. It will also allow you to use the operation block macro.
4 Add a dependency on spring-restdocs-mockmvc in the testImplementation configuration. If you want to use WebTestClient or REST Assured rather than MockMvc, add a dependency on spring-restdocs-webtestclient or spring-restdocs-restassured respectively instead.
5 Configure a property to define the output location for generated snippets.
6 Configure the test task to add the snippets directory as an output.
7 Configure the asciidoctor task.
8 Configure the snippets directory as an input.
9 Configure the use of the asciidoctorExt configuration for extensions.
10 Make the task depend on the test task so that the tests are run before the documentation is created.

Packaging the Documentation

You may want to package the generated documentation in your project’s jar file — for example, to have it served as static content by Spring Boot. To do so, configure your project’s build so that:

  1. The documentation is generated before the jar is built

  2. The generated documentation is included in the jar

The following listings show how to do so in both Maven and Gradle:

Maven
<plugin> (1)
	<groupId>org.asciidoctor</groupId>
	<artifactId>asciidoctor-maven-plugin</artifactId>
	<!-- … -->
</plugin>
<plugin> (2)
	<artifactId>maven-resources-plugin</artifactId>
	<version>2.7</version>
	<executions>
		<execution>
			<id>copy-resources</id>
			<phase>prepare-package</phase>
			<goals>
				<goal>copy-resources</goal>
			</goals>
			<configuration> (3)
				<outputDirectory>
					${project.build.outputDirectory}/static/docs
				</outputDirectory>
				<resources>
					<resource>
						<directory>
							${project.build.directory}/generated-docs
						</directory>
					</resource>
				</resources>
			</configuration>
		</execution>
	</executions>
</plugin>
1 The existing declaration for the Asciidoctor plugin.
2 The resource plugin must be declared after the Asciidoctor plugin as they are bound to the same phase (prepare-package) and the resource plugin must run after the Asciidoctor plugin to ensure that the documentation is generated before it’s copied.
3 Copy the generated documentation into the build output’s static/docs directory, from where it will be included in the jar file.
Gradle
bootJar {
	dependsOn asciidoctor (1)
	from ("${asciidoctor.outputDir}/html5") { (2)
		into 'static/docs'
	}
}
1 Ensure that the documentation has been generated before the jar is built.
2 Copy the generated documentation into the jar’s static/docs directory.

Generating Documentation Snippets

Spring REST Docs uses Spring MVC’s test framework, Spring WebFlux’s WebTestClient, or REST Assured to make requests to the service that you are documenting. It then produces documentation snippets for the request and the resulting response.

Setting up Your Tests

Exactly how you set up your tests depends on the test framework that you use. Spring REST Docs provides first-class support for JUnit 4 and JUnit 5. Other frameworks, such as TestNG, are also supported, although slightly more setup is required.

Setting up Your JUnit 4 Tests

When using JUnit 4, the first step in generating documentation snippets is to declare a public JUnitRestDocumentation field that is annotated as a JUnit @Rule. The following example shows how to do so:

@Rule
public JUnitRestDocumentation restDocumentation = new JUnitRestDocumentation();

By default, the JUnitRestDocumentation rule is automatically configured with an output directory based on your project’s build tool:

Build tool Output directory

Maven

target/generated-snippets

Gradle

build/generated-snippets

You can override the default by providing an output directory when you create the JUnitRestDocumentation instance. The following example shows how to do so:

@Rule
public JUnitRestDocumentation restDocumentation = new JUnitRestDocumentation("custom");

Next, you must provide an @Before method to configure MockMvc or WebTestClient, or REST Assured. The following examples show how to do so:

MockMvc
private MockMvc mockMvc;

@Autowired
private WebApplicationContext context;

@Before
public void setUp() {
	this.mockMvc = MockMvcBuilders.webAppContextSetup(this.context)
			.apply(documentationConfiguration(this.restDocumentation)) (1)
			.build();
}
1 The MockMvc instance is configured by using a MockMvcRestDocumentationConfigurer. You can obtain an instance of this class from the static documentationConfiguration() method on org.springframework.restdocs.mockmvc.MockMvcRestDocumentation.
WebTestClient
private WebTestClient webTestClient;

@Autowired
private ApplicationContext context;

@Before
public void setUp() {
	this.webTestClient = WebTestClient.bindToApplicationContext(this.context).configureClient()
			.filter(documentationConfiguration(this.restDocumentation)) (1)
			.build();
}
1 The WebTestClient instance is configured by adding a WebTestclientRestDocumentationConfigurer as an ExchangeFilterFunction. You can obtain an instance of this class from the static documentationConfiguration() method on org.springframework.restdocs.webtestclient.WebTestClientRestDocumentation.
REST Assured
private RequestSpecification spec;

@Before
public void setUp() {
	this.spec = new RequestSpecBuilder().addFilter(documentationConfiguration(this.restDocumentation)) (1)
			.build();
}
1 REST Assured is configured by adding a RestAssuredRestDocumentationConfigurer as a Filter. You can obtain an instance of this class from the static documentationConfiguration() method on RestAssuredRestDocumentation in the org.springframework.restdocs.restassured package.

The configurer applies sensible defaults and also provides an API for customizing the configuration. See the configuration section for more information.

Setting up Your JUnit 5 Tests

When using JUnit 5, the first step in generating documentation snippets is to apply the RestDocumentationExtension to your test class. The following example shows how to do so:

@ExtendWith(RestDocumentationExtension.class)
public class JUnit5ExampleTests {

When testing a typical Spring application, you should also apply the SpringExtension:

@ExtendWith({RestDocumentationExtension.class, SpringExtension.class})
public class JUnit5ExampleTests {

The RestDocumentationExtension is automatically configured with an output directory based on your project’s build tool:

Build tool Output directory

Maven

target/generated-snippets

Gradle

build/generated-snippets

If you are using JUnit 5.1, you can override the default by registering the extension as a field in your test class and providing an output directory when creating it. The following example shows how to do so:

public class JUnit5ExampleTests {

	@RegisterExtension
	final RestDocumentationExtension restDocumentation = new RestDocumentationExtension ("custom");

}

Next, you must provide a @BeforeEach method to configure MockMvc or WebTestClient, or REST Assured. The following listings show how to do so:

MockMvc
private MockMvc mockMvc;

@BeforeEach
void setUp(WebApplicationContext webApplicationContext, RestDocumentationContextProvider restDocumentation) {
	this.mockMvc = MockMvcBuilders.webAppContextSetup(webApplicationContext)
			.apply(documentationConfiguration(restDocumentation)) (1)
			.build();
}
1 The MockMvc instance is configured by using a MockMvcRestDocumentationConfigurer. You can obtain an instance of this class from the static documentationConfiguration() method on org.springframework.restdocs.mockmvc.MockMvcRestDocumentation.
WebTestClient
private WebTestClient webTestClient;

@BeforeEach
void setUp(ApplicationContext applicationContext, RestDocumentationContextProvider restDocumentation) {
	this.webTestClient = WebTestClient.bindToApplicationContext(applicationContext).configureClient()
			.filter(documentationConfiguration(restDocumentation)) (1)
			.build();
}
1 The WebTestClient instance is configured by adding a WebTestClientRestDocumentationConfigurer as an ExchangeFilterFunction. You can obtain an instance of this class from the static documentationConfiguration() method on org.springframework.restdocs.webtestclient.WebTestClientRestDocumentation.
REST Assured
private RequestSpecification spec;

@BeforeEach
void setUp(RestDocumentationContextProvider restDocumentation) {
	this.spec = new RequestSpecBuilder().addFilter(documentationConfiguration(restDocumentation)) (1)
			.build();
}
1 REST Assured is configured by adding a RestAssuredRestDocumentationConfigurer as a Filter. You can obtain an instance of this class from the static documentationConfiguration() method on RestAssuredRestDocumentation in the org.springframework.restdocs.restassured package.

The configurer applies sensible defaults and also provides an API for customizing the configuration. See the configuration section for more information.

Setting up your tests without JUnit

The configuration when JUnit is not being used is largely similar to when it is being used. This section describes the key differences. The TestNG sample also illustrates the approach.

The first difference is that you should use ManualRestDocumentation in place of JUnitRestDocumentation. Also, you do not need the @Rule annotation. The following example shows how to use ManualRestDocumentation:

private ManualRestDocumentation restDocumentation = new ManualRestDocumentation();

Secondly, you must call ManualRestDocumentation.beforeTest(Class, String) before each test. You can do so as part of the method that configures MockMvc, WebTestClient, or REST Assured. The following examples show how to do so:

MockMvc
private MockMvc mockMvc;

@Autowired
private WebApplicationContext context;

@BeforeMethod
public void setUp(Method method) {
	this.mockMvc = MockMvcBuilders.webAppContextSetup(this.context)
			.apply(documentationConfiguration(this.restDocumentation)).build();
	this.restDocumentation.beforeTest(getClass(), method.getName());
}
WebTestClient
private WebTestClient webTestClient;

@Autowired
private ApplicationContext context;

@BeforeMethod
public void setUp(Method method) {
	this.webTestClient = WebTestClient.bindToApplicationContext(this.context).configureClient()
			.filter(documentationConfiguration(this.restDocumentation)) (1)
			.build();
	this.restDocumentation.beforeTest(getClass(), method.getName());
}
REST Assured
private RequestSpecification spec;

@BeforeMethod
public void setUp(Method method) {
	this.spec = new RequestSpecBuilder().addFilter(documentationConfiguration(this.restDocumentation)).build();
	this.restDocumentation.beforeTest(getClass(), method.getName());
}

Finally, you must call ManualRestDocumentation.afterTest after each test. The following example shows how to do so with TestNG:

@AfterMethod
public void tearDown() {
	this.restDocumentation.afterTest();
}

Invoking the RESTful Service

Now that you have configured the testing framework, you can use it to invoke the RESTful service and document the request and response. The following examples show how to do so:

MockMvc
this.mockMvc.perform(get("/").accept(MediaType.APPLICATION_JSON)) (1)
		.andExpect(status().isOk()) (2)
		.andDo(document("index")); (3)
1 Invoke the root (/) of the service and indicate that an application/json response is required.
2 Assert that the service produced the expected response.
3 Document the call to the service, writing the snippets into a directory named index (which is located beneath the configured output directory). The snippets are written by a RestDocumentationResultHandler. You can obtain an instance of this class from the static document method on org.springframework.restdocs.mockmvc.MockMvcRestDocumentation.
WebTestClient
this.webTestClient.get().uri("/").accept(MediaType.APPLICATION_JSON) (1)
		.exchange().expectStatus().isOk() (2)
		.expectBody().consumeWith(document("index")); (3)
1 Invoke the root (/) of the service and indicate that an application/json response is required.
2 Assert that the service produced the expected response.
3 Document the call to the service, writing the snippets into a directory named index (which is located beneath the configured output directory). The snippets are written by a Consumer of the ExchangeResult. You can obtain such a consumer from the static document method on org.springframework.restdocs.webtestclient.WebTestClientRestDocumentation.
REST Assured
RestAssured.given(this.spec) (1)
		.accept("application/json") (2)
		.filter(document("index")) (3)
		.when().get("/") (4)
		.then().assertThat().statusCode(is(200)); (5)
1 Apply the specification that was initialized in the @Before method.
2 Indicate that an application/json response is required.
3 Document the call to the service, writing the snippets into a directory named index (which is located beneath the configured output directory). The snippets are written by a RestDocumentationFilter. You can obtain an instance of this class from the static document method on RestAssuredRestDocumentation in the org.springframework.restdocs.restassured package.
4 Invoke the root (/) of the service.
5 Assert that the service produce the expected response.

By default, six snippets are written:

  • <output-directory>/index/curl-request.adoc

  • <output-directory>/index/http-request.adoc

  • <output-directory>/index/http-response.adoc

  • <output-directory>/index/httpie-request.adoc

  • <output-directory>/index/request-body.adoc

  • <output-directory>/index/response-body.adoc

See Documenting your API for more information about these and other snippets that can be produced by Spring REST Docs.

Using the Snippets

Before using the generated snippets, you must create an .adoc source file. You can name the file whatever you like as long as it has a .adoc suffix. The resulting HTML file has the same name but with a .html suffix. The default location of the source files and the resulting HTML files depends on whether you use Maven or Gradle:

Build tool Source files Generated files

Maven

src/main/asciidoc/*.adoc

target/generated-docs/*.html

Gradle

src/docs/asciidoc/*.adoc

build/asciidoc/html5/*.html

You can then include the generated snippets in the manually created Asciidoc file (described earlier in this section) by using the include macro. You can use the snippets attribute that is automatically set by spring-restdocs-asciidoctor configured in the build configuration to reference the snippets output directory. The following example shows how to do so:

include::{snippets}/index/curl-request.adoc[]

Documenting your API

This section provides more details about using Spring REST Docs to document your API.

Hypermedia

Spring REST Docs provides support for documenting the links in a hypermedia-based API. The following examples show how to use it:

MockMvc
this.mockMvc.perform(get("/").accept(MediaType.APPLICATION_JSON)).andExpect(status().isOk())
		.andDo(document("index", links((1)
				linkWithRel("alpha").description("Link to the alpha resource"), (2)
				linkWithRel("bravo").description("Link to the bravo resource")))); (3)
1 Configure Spring REST docs to produce a snippet describing the response’s links. Uses the static links method on org.springframework.restdocs.hypermedia.HypermediaDocumentation.
2 Expect a link whose rel is alpha. Uses the static linkWithRel method on org.springframework.restdocs.hypermedia.HypermediaDocumentation.
3 Expect a link whose rel is bravo.
WebTestClient
this.webTestClient.get().uri("/").accept(MediaType.APPLICATION_JSON).exchange().expectStatus().isOk()
		.expectBody().consumeWith(document("index", links((1)
				linkWithRel("alpha").description("Link to the alpha resource"), (2)
				linkWithRel("bravo").description("Link to the bravo resource")))); (3)
1 Configure Spring REST docs to produce a snippet describing the response’s links. Uses the static links method on org.springframework.restdocs.hypermedia.HypermediaDocumentation.
2 Expect a link whose rel is alpha. Uses the static linkWithRel method on org.springframework.restdocs.hypermedia.HypermediaDocumentation.
3 Expect a link whose rel is bravo.
REST Assured
RestAssured.given(this.spec).accept("application/json").filter(document("index", links((1)
		linkWithRel("alpha").description("Link to the alpha resource"), (2)
		linkWithRel("bravo").description("Link to the bravo resource")))) (3)
		.get("/").then().assertThat().statusCode(is(200));
1 Configure Spring REST docs to produce a snippet describing the response’s links. Uses the static links method on org.springframework.restdocs.hypermedia.HypermediaDocumentation.
2 Expect a link whose rel is alpha. Uses the static linkWithRel method on org.springframework.restdocs.hypermedia.HypermediaDocumentation.
3 Expect a link whose rel is bravo.

The result is a snippet named links.adoc that contains a table describing the resource’s links.

If a link in the response has a title, you can omit the description from its descriptor and the title is used. If you omit the description and the link does not have a title, a failure occurs.

When documenting links, the test fails if an undocumented link is found in the response. Similarly, the test also fails if a documented link is not found in the response and the link has not been marked as optional.

If you do not want to document a link, you can mark it as ignored. Doing so prevents it from appearing in the generated snippet while avoiding the failure described above.

You can also document links in a relaxed mode, where any undocumented links do not cause a test failure. To do so, use the relaxedLinks method on org.springframework.restdocs.hypermedia.HypermediaDocumentation. This can be useful when documenting a particular scenario where you only want to focus on a subset of the links.

Two link formats are understood by default:

  • Atom: Links are expected to be in an array named links. This is used by default when the content type of the response is compatible with application/json.

  • HAL: Links are expected to be in a map named _links. This is used by default when the content type of the response is compatible with application/hal+json.

If you use Atom- or HAL-format links but with a different content type, you can provide one of the built-in LinkExtractor implementations to links. The following examples show how to do so:

MockMvc
.andDo(document("index", links(halLinks(), (1)
		linkWithRel("alpha").description("Link to the alpha resource"),
		linkWithRel("bravo").description("Link to the bravo resource"))));
1 Indicate that the links are in HAL format. Uses the static halLinks method on org.springframework.restdocs.hypermedia.HypermediaDocumentation.
WebTestClient
.consumeWith(document("index", links(halLinks(), (1)
		linkWithRel("alpha").description("Link to the alpha resource"),
		linkWithRel("bravo").description("Link to the bravo resource"))));
1 Indicate that the links are in HAL format. Uses the static halLinks method on org.springframework.restdocs.hypermedia.HypermediaDocumentation.
REST Assured
.filter(document("index", links(halLinks(), (1)
		linkWithRel("alpha").description("Link to the alpha resource"),
		linkWithRel("bravo").description("Link to the bravo resource"))))
1 Indicate that the links are in HAL format. Uses the static halLinks method on org.springframework.restdocs.hypermedia.HypermediaDocumentation.

If your API represents its links in a format other than Atom or HAL, you can provide your own implementation of the LinkExtractor interface to extract the links from the response.

Rather than documenting links that are common to every response, such as self and curies when using HAL, you may want to document them once in an overview section and then ignore them in the rest of your API’s documentation. To do so, you can build on the support for reusing snippets to add link descriptors to a snippet that is preconfigured to ignore certain links. The following example shows how to do so:

public static LinksSnippet links(LinkDescriptor... descriptors) {
	return HypermediaDocumentation.links(linkWithRel("self").ignored().optional(), linkWithRel("curies").ignored())
			.and(descriptors);
}

Request and Response Payloads

In addition to the hypermedia-specific support described earlier, support for general documentation of request and response payloads is also provided.

By default, Spring REST Docs automatically generates snippets for the body of the request and the body of the response. These snippets are named request-body.adoc and response-body.adoc respectively.

Request and Response Fields

To provide more detailed documentation of a request or response payload, support for documenting the payload’s fields is provided.

Consider the following payload:

{
	"contact": {
		"name": "Jane Doe",
		"email": "jane.doe@example.com"
	}
}

You can document the previous example’s fields as follows:

MockMvc
this.mockMvc.perform(get("/user/5").accept(MediaType.APPLICATION_JSON)).andExpect(status().isOk())
		.andDo(document("index", responseFields((1)
				fieldWithPath("contact.email").description("The user's email address"), (2)
				fieldWithPath("contact.name").description("The user's name")))); (3)
1 Configure Spring REST docs to produce a snippet describing the fields in the response payload. To document a request, you can use requestFields. Both are static methods on org.springframework.restdocs.payload.PayloadDocumentation.
2 Expect a field with the path contact.email. Uses the static fieldWithPath method on org.springframework.restdocs.payload.PayloadDocumentation.
3 Expect a field with the path contact.name.
WebTestClient
this.webTestClient.get().uri("user/5").accept(MediaType.APPLICATION_JSON)
	.exchange().expectStatus().isOk().expectBody()
	.consumeWith(document("user",
		responseFields((1)
			fieldWithPath("contact.email").description("The user's email address"), (2)
			fieldWithPath("contact.name").description("The user's name")))); (3)
1 Configure Spring REST docs to produce a snippet describing the fields in the response payload. To document a request, you can use requestFields. Both are static methods on org.springframework.restdocs.payload.PayloadDocumentation.
2 Expect a field with the path contact.email. Uses the static fieldWithPath method on org.springframework.restdocs.payload.PayloadDocumentation.
3 Expect a field with the path contact.name.
REST Assured
RestAssured.given(this.spec).accept("application/json").filter(document("user", responseFields((1)
		fieldWithPath("contact.name").description("The user's name"), (2)
		fieldWithPath("contact.email").description("The user's email address")))) (3)
		.when().get("/user/5").then().assertThat().statusCode(is(200));
1 Configure Spring REST docs to produce a snippet describing the fields in the response payload. To document a request, you can use requestFields. Both are static methods on org.springframework.restdocs.payload.PayloadDocumentation.
2 Expect a field with the path contact.email. Uses the static fieldWithPath method on org.springframework.restdocs.payload.PayloadDocumentation.
3 Expect a field with the path contact.name.

The result is a snippet that contains a table describing the fields. For requests, this snippet is named request-fields.adoc. For responses, this snippet is named response-fields.adoc.

When documenting fields, the test fails if an undocumented field is found in the payload. Similarly, the test also fails if a documented field is not found in the payload and the field has not been marked as optional.

If you do not want to provide detailed documentation for all of the fields, an entire subsection of a payload can be documented. The following examples show how to do so:

MockMvc
this.mockMvc.perform(get("/user/5").accept(MediaType.APPLICATION_JSON)).andExpect(status().isOk())
		.andDo(document("index", responseFields((1)
				subsectionWithPath("contact").description("The user's contact details")))); (1)
1 Document the subsection with the path contact. contact.email and contact.name are now seen as having also been documented. Uses the static subsectionWithPath method on org.springframework.restdocs.payload.PayloadDocumentation.
WebTestClient
this.webTestClient.get().uri("user/5").accept(MediaType.APPLICATION_JSON)
	.exchange().expectStatus().isOk().expectBody()
	.consumeWith(document("user",
		responseFields(
			subsectionWithPath("contact").description("The user's contact details")))); (1)
1 Document the subsection with the path contact. contact.email and contact.name are now seen as having also been documented. Uses the static subsectionWithPath method on org.springframework.restdocs.payload.PayloadDocumentation.
REST Assured
RestAssured.given(this.spec).accept("application/json")
		.filter(document("user",
				responseFields(subsectionWithPath("contact").description("The user's contact details")))) (1)
		.when().get("/user/5").then().assertThat().statusCode(is(200));
1 Document the subsection with the path contact. contact.email and contact.name are now seen as having also been documented. Uses the static subsectionWithPath method on org.springframework.restdocs.payload.PayloadDocumentation.

subsectionWithPath can be useful for providing a high-level overview of a particular section of a payload. You can then produce separate, more detailed documentation for a subsection. See Documenting a Subsection of a Request or Response Payload.

If you do not want to document a field or subsection at all, you can mark it as ignored. This prevents it from appearing in the generated snippet while avoiding the failure described earlier.

You can also document fields in a relaxed mode, where any undocumented fields do not cause a test failure. To do so, use the relaxedRequestFields and relaxedResponseFields methods on org.springframework.restdocs.payload.PayloadDocumentation. This can be useful when documenting a particular scenario where you want to focus only on a subset of the payload.

By default, Spring REST Docs assumes that the payload you are documenting is JSON. If you want to document an XML payload, the content type of the request or response must be compatible with application/xml.
Fields in JSON Payloads

This section describes how to work with fields in JSON payloads.

JSON Field Paths

JSON field paths use either dot notation or bracket notation. Dot notation uses '.' to separate each key in the path (for example, a.b). Bracket notation wraps each key in square brackets and single quotation marks (for example, ['a']['b']). In either case, [] is used to identify an array. Dot notation is more concise, but using bracket notation enables the use of . within a key name (for example, ['a.b']). The two different notations can be used in the same path (for example, a['b']).

Consider the following JSON payload:

{
	"a":{
		"b":[
			{
				"c":"one"
			},
			{
				"c":"two"
			},
			{
				"d":"three"
			}
		],
		"e.dot" : "four"
	}
}

In the preceding JSON payload, the following paths are all present:

Path Value

a

An object containing b

a.b

An array containing three objects

['a']['b']

An array containing three objects

a['b']

An array containing three objects

['a'].b

An array containing three objects

a.b[]

An array containing three objects

a.b[].c

An array containing the strings one and two

a.b[].d

The string three

a['e.dot']

The string four

['a']['e.dot']

The string four

You can also document a payload that uses an array at its root. The path [] refers to the entire array. You can then use bracket or dot notation to identify fields within the array’s entries. For example, [].id corresponds to the id field of every object found in the following array:

[
	{
		"id":1
	},
	{
		"id":2
	}
]

You can use * as a wildcard to match fields with different names. For example, users.*.role could be used to document the role of every user in the following JSON:

{
	"users":{
		"ab12cd34":{
			"role": "Administrator"
		},
		"12ab34cd":{
			"role": "Guest"
		}
	}
}
JSON Field Types

When a field is documented, Spring REST Docs tries to determine its type by examining the payload. Seven different types are supported:

Type Description

array

The value of each occurrence of the field is an array.

boolean

The value of each occurrence of the field is a boolean (true or false).

object

The value of each occurrence of the field is an object.

number

The value of each occurrence of the field is a number.

null

The value of each occurrence of the field is null.

string

The value of each occurrence of the field is a string.

varies

The field occurs multiple times in the payload with a variety of different types.

You can also explicitly set the type by using the type(Object) method on FieldDescriptor. The result of the toString method of the supplied Object is used in the documentation. Typically, one of the values enumerated by JsonFieldType is used. The following examples show how to do so:

MockMvc
.andDo(document("index", responseFields(fieldWithPath("contact.email").type(JsonFieldType.STRING) (1)
		.description("The user's email address"))));
1 Set the field’s type to String.
WebTestClient
.consumeWith(document("user",
	responseFields(
		fieldWithPath("contact.email")
			.type(JsonFieldType.STRING) (1)
			.description("The user's email address"))));
1 Set the field’s type to String.
REST Assured
.filter(document("user", responseFields(fieldWithPath("contact.email").type(JsonFieldType.STRING) (1)
		.description("The user's email address"))))
1 Set the field’s type to String.
XML payloads

This section describes how to work with XML payloads.

XML Field Paths

XML field paths are described using XPath. / is used to descend into a child node.

XML Field Types

When documenting an XML payload, you must provide a type for the field by using the type(Object) method on FieldDescriptor. The result of the supplied type’s toString method is used in the documentation.

Reusing Field Descriptors

In addition to the general support for reusing snippets, the request and response snippets let additional descriptors be configured with a path prefix. This lets the descriptors for a repeated portion of a request or response payload be created once and then reused.

Consider an endpoint that returns a book:

{
	"title": "Pride and Prejudice",
	"author": "Jane Austen"
}

The paths for title and author are title and author, respectively.

Now consider an endpoint that returns an array of books:

[{
	"title": "Pride and Prejudice",
	"author": "Jane Austen"
},
{
	"title": "To Kill a Mockingbird",
	"author": "Harper Lee"
}]

The paths for title and author are [].title and [].author, respectively. The only difference between the single book and the array of books is that the fields' paths now have a []. prefix.

You can create the descriptors that document a book as follows:

FieldDescriptor[] book = new FieldDescriptor[] { fieldWithPath("title").description("Title of the book"),
		fieldWithPath("author").description("Author of the book") };

You can then use them to document a single book, as follows:

MockMvc
this.mockMvc.perform(get("/books/1").accept(MediaType.APPLICATION_JSON)).andExpect(status().isOk())
		.andDo(document("book", responseFields(book))); (1)
1 Document title and author by using existing descriptors
WebTestClient
this.webTestClient.get().uri("/books/1").accept(MediaType.APPLICATION_JSON)
	.exchange().expectStatus().isOk().expectBody()
	.consumeWith(document("book",
		responseFields(book))); (1)
1 Document title and author by using existing descriptors
REST Assured
RestAssured.given(this.spec).accept("application/json").filter(document("book", responseFields(book))) (1)
		.when().get("/books/1").then().assertThat().statusCode(is(200));
1 Document title and author by using existing descriptors

You can also use the descriptors to document an array of books, as follows:

MockMvc
this.mockMvc.perform(get("/books").accept(MediaType.APPLICATION_JSON)).andExpect(status().isOk())
		.andDo(document("book", responseFields(fieldWithPath("[]").description("An array of books")) (1)
				.andWithPrefix("[].", book))); (2)
1 Document the array.
2 Document [].title and [].author by using the existing descriptors prefixed with [].
WebTestClient
this.webTestClient.get().uri("/books").accept(MediaType.APPLICATION_JSON)
	.exchange().expectStatus().isOk().expectBody()
	.consumeWith(document("books",
		responseFields(
			fieldWithPath("[]")
				.description("An array of books")) (1)
				.andWithPrefix("[].", book))); (2)
1 Document the array.
2 Document [].title and [].author by using the existing descriptors prefixed with [].
REST Assured
RestAssured.given(this.spec).accept("application/json")
		.filter(document("books", responseFields(fieldWithPath("[]").description("An array of books")) (1)
				.andWithPrefix("[].", book))) (2)
		.when().get("/books").then().assertThat().statusCode(is(200));
1 Document the array.
2 Document [].title and [].author by using the existing descriptors prefixed with [].

Documenting a Subsection of a Request or Response Payload

If a payload is large or structurally complex, it can be useful to document individual sections of the payload. REST Docs let you do so by extracting a subsection of the payload and then documenting it.

Documenting a Subsection of a Request or Response Body

Consider the following JSON response body:

{
	"weather": {
		"wind": {
			"speed": 15.3,
			"direction": 287.0
		},
		"temperature": {
			"high": 21.2,
			"low": 14.8
		}
	}
}

You can produce a snippet that documents the temperature object as follows:

MockMvc
this.mockMvc.perform(get("/locations/1").accept(MediaType.APPLICATION_JSON)).andExpect(status().isOk())
		.andDo(document("location", responseBody(beneathPath("weather.temperature")))); (1)
1 Produce a snippet containing a subsection of the response body. Uses the static responseBody and beneathPath methods on org.springframework.restdocs.payload.PayloadDocumentation. To produce a snippet for the request body, you can use requestBody in place of responseBody.
WebTestClient
this.webTestClient.get().uri("/locations/1").accept(MediaType.APPLICATION_JSON)
	.exchange().expectStatus().isOk().expectBody()
	.consumeWith(document("temperature",
		responseBody(beneathPath("weather.temperature")))); (1)
1 Produce a snippet containing a subsection of the response body. Uses the static responseBody and beneathPath methods on org.springframework.restdocs.payload.PayloadDocumentation. To produce a snippet for the request body, you can use requestBody in place of responseBody.
REST Assured
RestAssured.given(this.spec).accept("application/json")
		.filter(document("location", responseBody(beneathPath("weather.temperature")))) (1)
		.when().get("/locations/1").then().assertThat().statusCode(is(200));
1 Produce a snippet containing a subsection of the response body. Uses the static responseBody and beneathPath methods on org.springframework.restdocs.payload.PayloadDocumentation. To produce a snippet for the request body, you can use requestBody in place of responseBody.

The result is a snippet with the following contents:

{
	"temperature": {
		"high": 21.2,
		"low": 14.8
	}
}

To make the snippet’s name distinct, an identifier for the subsection is included. By default, this identifier is beneath-${path}. For example, the preceding code results in a snippet named response-body-beneath-weather.temperature.adoc. You can customize the identifier by using the withSubsectionId(String) method, as follows:

responseBody(beneathPath("weather.temperature").withSubsectionId("temp"));

The result is a snippet named request-body-temp.adoc.

Documenting the Fields of a Subsection of a Request or Response

As well as documenting a subsection of a request or response body, you can also document the fields in a particular subsection. You can produce a snippet that documents the fields of the temperature object (high and low) as follows:

MockMvc
this.mockMvc.perform(get("/locations/1").accept(MediaType.APPLICATION_JSON)).andExpect(status().isOk())
		.andDo(document("location", responseFields(beneathPath("weather.temperature"), (1)
				fieldWithPath("high").description("The forecast high in degrees celcius"), (2)
				fieldWithPath("low").description("The forecast low in degrees celcius"))));
1 Produce a snippet describing the fields in the subsection of the response payload beneath the path weather.temperature. Uses the static beneathPath method on org.springframework.restdocs.payload.PayloadDocumentation.
2 Document the high and low fields.
WebTestClient
this.webTestClient.get().uri("/locations/1").accept(MediaType.APPLICATION_JSON)
	.exchange().expectStatus().isOk().expectBody()
	.consumeWith(document("temperature",
		responseFields(beneathPath("weather.temperature"), (1)
			fieldWithPath("high").description("The forecast high in degrees celcius"), (2)
			fieldWithPath("low").description("The forecast low in degrees celcius"))));
1 Produce a snippet describing the fields in the subsection of the response payload beneath the path weather.temperature. Uses the static beneathPath method on org.springframework.restdocs.payload.PayloadDocumentation.
2 Document the high and low fields.
REST Assured
RestAssured.given(this.spec).accept("application/json")
		.filter(document("location", responseFields(beneathPath("weather.temperature"), (1)
				fieldWithPath("high").description("The forecast high in degrees celcius"), (2)
				fieldWithPath("low").description("The forecast low in degrees celcius"))))
		.when().get("/locations/1").then().assertThat().statusCode(is(200));
1 Produce a snippet describing the fields in the subsection of the response payload beneath the path weather.temperature. Uses the static beneathPath method on org.springframework.restdocs.payload.PayloadDocumentation.
2 Document the high and low fields.

The result is a snippet that contains a table describing the high and low fields of weather.temperature. To make the snippet’s name distinct, an identifier for the subsection is included. By default, this identifier is beneath-${path}. For example, the preceding code results in a snippet named response-fields-beneath-weather.temperature.adoc.

Request Parameters

You can document a request’s parameters by using requestParameters. You can include request parameters in a GET request’s query string. The following examples show how to do so:

MockMvc
this.mockMvc.perform(get("/users?page=2&per_page=100")) (1)
		.andExpect(status().isOk()).andDo(document("users", requestParameters((2)
				parameterWithName("page").description("The page to retrieve"), (3)
				parameterWithName("per_page").description("Entries per page") (4)
		)));
1 Perform a GET request with two parameters, page and per_page, in the query string.
2 Configure Spring REST Docs to produce a snippet describing the request’s parameters. Uses the static requestParameters method on org.springframework.restdocs.request.RequestDocumentation.
3 Document the page parameter. Uses the static parameterWithName method on org.springframework.restdocs.request.RequestDocumentation.
4 Document the per_page parameter.
WebTestClient
this.webTestClient.get().uri("/users?page=2&per_page=100") (1)
	.exchange().expectStatus().isOk().expectBody()
	.consumeWith(document("users", requestParameters((2)
			parameterWithName("page").description("The page to retrieve"), (3)
			parameterWithName("per_page").description("Entries per page") (4)
	)));
1 Perform a GET request with two parameters, page and per_page, in the query string.
2 Configure Spring REST Docs to produce a snippet describing the request’s parameters. Uses the static requestParameters method on org.springframework.restdocs.request.RequestDocumentation.
3 Document the page parameter. Uses the static parameterWithName method on org.springframework.restdocs.request.RequestDocumentation.
4 Document the per_page parameter.
REST Assured
RestAssured.given(this.spec).filter(document("users", requestParameters((1)
		parameterWithName("page").description("The page to retrieve"), (2)
		parameterWithName("per_page").description("Entries per page")))) (3)
		.when().get("/users?page=2&per_page=100") (4)
		.then().assertThat().statusCode(is(200));
1 Configure Spring REST Docs to produce a snippet describing the request’s parameters. Uses the static requestParameters method on org.springframework.restdocs.request.RequestDocumentation.
2 Document the page parameter. Uses the static parameterWithName method on org.springframework.restdocs.request.RequestDocumentation.
3 Document the per_page parameter.
4 Perform a GET request with two parameters, page and per_page, in the query string.

You can also include request parameters as form data in the body of a POST request. The following examples show how to do so:

MockMvc
this.mockMvc.perform(post("/users").param("username", "Tester")) (1)
		.andExpect(status().isCreated()).andDo(document("create-user",
				requestParameters(parameterWithName("username").description("The user's username"))));
1 Perform a POST request with a single parameter, username.
WebTestClient
MultiValueMap<String, String> formData = new LinkedMultiValueMap<>();
formData.add("username", "Tester");
this.webTestClient.post().uri("/users").body(BodyInserters.fromFormData(formData)) (1)
	.exchange().expectStatus().isCreated().expectBody()
	.consumeWith(document("create-user", requestParameters(
		parameterWithName("username").description("The user's username")
)));
1 Perform a POST request with a single parameter, username.
REST Assured
RestAssured.given(this.spec)
		.filter(document("create-user",
				requestParameters(parameterWithName("username").description("The user's username"))))
		.formParam("username", "Tester") (1)
		.when().post("/users") (2)
		.then().assertThat().statusCode(is(200));
1 Configure the username parameter.
2 Perform the POST request.

In all cases, the result is a snippet named request-parameters.adoc that contains a table describing the parameters that are supported by the resource.

When documenting request parameters, the test fails if an undocumented request parameter is used in the request. Similarly, the test also fails if a documented request parameter is not found in the request and the request parameter has not been marked as optional.

If you do not want to document a request parameter, you can mark it as ignored. This prevents it from appearing in the generated snippet while avoiding the failure described above.

You can also document request parameters in a relaxed mode where any undocumented parameters do not cause a test failure. To do so, use the relaxedRequestParameters method on org.springframework.restdocs.request.RequestDocumentation. This can be useful when documenting a particular scenario where you only want to focus on a subset of the request parameters.

Path Parameters

You can document a request’s path parameters by using pathParameters. The following examples show how to do so:

MockMvc
this.mockMvc.perform(get("/locations/{latitude}/{longitude}", 51.5072, 0.1275)) (1)
		.andExpect(status().isOk()).andDo(document("locations", pathParameters((2)
				parameterWithName("latitude").description("The location's latitude"), (3)
				parameterWithName("longitude").description("The location's longitude") (4)
		)));
1 Perform a GET request with two path parameters, latitude and longitude.
2 Configure Spring REST Docs to produce a snippet describing the request’s path parameters. Uses the static pathParameters method on org.springframework.restdocs.request.RequestDocumentation.
3 Document the parameter named latitude. Uses the static parameterWithName method on org.springframework.restdocs.request.RequestDocumentation.
4 Document the parameter named longitude.
WebTestClient
this.webTestClient.get().uri("/locations/{latitude}/{longitude}", 51.5072, 0.1275) (1)
	.exchange().expectStatus().isOk().expectBody()
	.consumeWith(document("locations",
		pathParameters((2)
			parameterWithName("latitude").description("The location's latitude"), (3)
			parameterWithName("longitude").description("The location's longitude")))); (4)
1 Perform a GET request with two path parameters, latitude and longitude.
2 Configure Spring REST Docs to produce a snippet describing the request’s path parameters. Uses the static pathParameters method on org.springframework.restdocs.request.RequestDocumentation.
3 Document the parameter named latitude. Uses the static parameterWithName method on org.springframework.restdocs.request.RequestDocumentation.
4 Document the parameter named longitude.
REST Assured
RestAssured.given(this.spec).filter(document("locations", pathParameters((1)
		parameterWithName("latitude").description("The location's latitude"), (2)
		parameterWithName("longitude").description("The location's longitude")))) (3)
		.when().get("/locations/{latitude}/{longitude}", 51.5072, 0.1275) (4)
		.then().assertThat().statusCode(is(200));
1 Configure Spring REST Docs to produce a snippet describing the request’s path parameters. Uses the static pathParameters method on org.springframework.restdocs.request.RequestDocumentation.
2 Document the parameter named latitude. Uses the static parameterWithName method on org.springframework.restdocs.request.RequestDocumentation.
3 Document the parameter named longitude.
4 Perform a GET request with two path parameters, latitude and longitude.

The result is a snippet named path-parameters.adoc that contains a table describing the path parameters that are supported by the resource.

If you use MockMvc, to make the path parameters available for documentation, you must build the request by using one of the methods on RestDocumentationRequestBuilders rather than MockMvcRequestBuilders.

When documenting path parameters, the test fails if an undocumented path parameter is used in the request. Similarly, the test also fails if a documented path parameter is not found in the request and the path parameter has not been marked as optional.

You can also document path parameters in a relaxed mode, where any undocumented parameters do not cause a test failure. To do so, use the relaxedPathParameters method on org.springframework.restdocs.request.RequestDocumentation. This can be useful when documenting a particular scenario where you only want to focus on a subset of the path parameters.

If you do not want to document a path parameter, you can mark it as ignored. Doing so prevents it from appearing in the generated snippet while avoiding the failure described earlier.

Request Parts

You can use requestParts to document the parts of a multipart request. The following example shows how to do so:

MockMvc
this.mockMvc.perform(multipart("/upload").file("file", "example".getBytes())) (1)
		.andExpect(status().isOk()).andDo(document("upload", requestParts((2)
				partWithName("file").description("The file to upload")) (3)
		));
1 Perform a POST request with a single part named file.
2 Configure Spring REST Docs to produce a snippet describing the request’s parts. Uses the static requestParts method on org.springframework.restdocs.request.RequestDocumentation.
3 Document the part named file. Uses the static partWithName method on org.springframework.restdocs.request.RequestDocumentation.
WebTestClient
MultiValueMap<String, Object> multipartData = new LinkedMultiValueMap<>();
multipartData.add("file", "example".getBytes());
this.webTestClient.post().uri("/upload").body(BodyInserters.fromMultipartData(multipartData)) (1)
	.exchange().expectStatus().isOk().expectBody()
	.consumeWith(document("upload", requestParts((2)
		partWithName("file").description("The file to upload")) (3)
));
1 Perform a POST request with a single part named file.
2 Configure Spring REST Docs to produce a snippet describing the request’s parts. Uses the static requestParts method on org.springframework.restdocs.request.RequestDocumentation.
3 Document the part named file. Uses the static partWithName method on org.springframework.restdocs.request.RequestDocumentation.
REST Assured
RestAssured.given(this.spec).filter(document("users", requestParts((1)
		partWithName("file").description("The file to upload")))) (2)
		.multiPart("file", "example") (3)
		.when().post("/upload") (4)
		.then().statusCode(is(200));
1 Configure Spring REST Docs to produce a snippet describing the request’s parts. Uses the static requestParts method on org.springframework.restdocs.request.RequestDocumentation.
2 Document the part named file. Uses the static partWithName method on org.springframework.restdocs.request.RequestDocumentation.
3 Configure the request with the part named file.
4 Perform the POST request to /upload.

The result is a snippet named request-parts.adoc that contains a table describing the request parts that are supported by the resource.

When documenting request parts, the test fails if an undocumented part is used in the request. Similarly, the test also fails if a documented part is not found in the request and the part has not been marked as optional.

You can also document request parts in a relaxed mode where any undocumented parts do not cause a test failure. To do so, use the relaxedRequestParts method on org.springframework.restdocs.request.RequestDocumentation. This can be useful when documenting a particular scenario where you only want to focus on a subset of the request parts.

If you do not want to document a request part, you can mark it as ignored. This prevents it from appearing in the generated snippet while avoiding the failure described earlier.

Request Part Payloads

You can document the payload of a request part in much the same way as the payload of a request, with support for documenting a request part’s body and its fields.

Documenting a Request Part’s Body

You can generate a snippet containing the body of a request part as follows:

MockMvc
MockMultipartFile image = new MockMultipartFile("image", "image.png", "image/png", "<<png data>>".getBytes());
MockMultipartFile metadata = new MockMultipartFile("metadata", "", "application/json",
		"{ \"version\": \"1.0\"}".getBytes());

this.mockMvc.perform(multipart("/images").file(image).file(metadata).accept(MediaType.APPLICATION_JSON))
		.andExpect(status().isOk()).andDo(document("image-upload", requestPartBody("metadata"))); (1)
1 Configure Spring REST docs to produce a snippet containing the body of the request part named metadata. Uses the static requestPartBody method on PayloadDocumentation.
WebTestClient
MultiValueMap<String, Object> multipartData = new LinkedMultiValueMap<>();
Resource imageResource = new ByteArrayResource("<<png data>>".getBytes()) {

	@Override
	public String getFilename() {
		return "image.png";
	}

};
multipartData.add("image", imageResource);
multipartData.add("metadata", Collections.singletonMap("version",  "1.0"));

this.webTestClient.post().uri("/images").body(BodyInserters.fromMultipartData(multipartData))
	.accept(MediaType.APPLICATION_JSON).exchange()
	.expectStatus().isOk().expectBody()
	.consumeWith(document("image-upload",
			requestPartBody("metadata"))); (1)
1 Configure Spring REST docs to produce a snippet containing the body of the request part named metadata. Uses the static requestPartBody method on PayloadDocumentation.
REST Assured
Map<String, String> metadata = new HashMap<>();
metadata.put("version", "1.0");
RestAssured.given(this.spec).accept("application/json")
		.filter(document("image-upload", requestPartBody("metadata"))) (1)
		.when().multiPart("image", new File("image.png"), "image/png").multiPart("metadata", metadata)
		.post("images").then().assertThat().statusCode(is(200));
1 Configure Spring REST docs to produce a snippet containing the body of the request part named metadata. Uses the static requestPartBody method on PayloadDocumentation.

The result is a snippet named request-part-${part-name}-body.adoc that contains the part’s body. For example, documenting a part named metadata produces a snippet named request-part-metadata-body.adoc.

Documenting a Request Part’s Fields

You can document a request part’s fields in much the same way as the fields of a request or response, as follows:

MockMvc
MockMultipartFile image = new MockMultipartFile("image", "image.png", "image/png", "<<png data>>".getBytes());
MockMultipartFile metadata = new MockMultipartFile("metadata", "", "application/json",
		"{ \"version\": \"1.0\"}".getBytes());

this.mockMvc.perform(multipart("/images").file(image).file(metadata).accept(MediaType.APPLICATION_JSON))
		.andExpect(status().isOk()).andDo(document("image-upload", requestPartFields("metadata", (1)
				fieldWithPath("version").description("The version of the image")))); (2)
1 Configure Spring REST docs to produce a snippet describing the fields in the payload of the request part named metadata. Uses the static requestPartFields method on PayloadDocumentation.
2 Expect a field with the path version. Uses the static fieldWithPath method on org.springframework.restdocs.payload.PayloadDocumentation.
WebTestClient
MultiValueMap<String, Object> multipartData = new LinkedMultiValueMap<>();
Resource imageResource = new ByteArrayResource("<<png data>>".getBytes()) {

	@Override
	public String getFilename() {
		return "image.png";
	}

};
multipartData.add("image", imageResource);
multipartData.add("metadata", Collections.singletonMap("version",  "1.0"));
this.webTestClient.post().uri("/images").body(BodyInserters.fromMultipartData(multipartData))
	.accept(MediaType.APPLICATION_JSON).exchange()
	.expectStatus().isOk().expectBody()
	.consumeWith(document("image-upload",
		requestPartFields("metadata", (1)
			fieldWithPath("version").description("The version of the image")))); (2)
1 Configure Spring REST docs to produce a snippet describing the fields in the payload of the request part named metadata. Uses the static requestPartFields method on PayloadDocumentation.
2 Expect a field with the path version. Uses the static fieldWithPath method on org.springframework.restdocs.payload.PayloadDocumentation.
REST Assured
Map<String, String> metadata = new HashMap<>();
metadata.put("version", "1.0");
RestAssured.given(this.spec).accept("application/json")
		.filter(document("image-upload", requestPartFields("metadata", (1)
				fieldWithPath("version").description("The version of the image")))) (2)
		.when().multiPart("image", new File("image.png"), "image/png").multiPart("metadata", metadata)
		.post("images").then().assertThat().statusCode(is(200));
1 Configure Spring REST docs to produce a snippet describing the fields in the payload of the request part named metadata. Uses the static requestPartFields method on PayloadDocumentation.
2 Expect a field with the path version. Uses the static fieldWithPath method on org.springframework.restdocs.payload.PayloadDocumentation.

The result is a snippet that contains a table describing the part’s fields. This snippet is named request-part-${part-name}-fields.adoc. For example, documenting a part named metadata produces a snippet named request-part-metadata-fields.adoc.

When documenting fields, the test fails if an undocumented field is found in the payload of the part. Similarly, the test also fails if a documented field is not found in the payload of the part and the field has not been marked as optional. For payloads with a hierarchical structure, documenting a field is sufficient for all of its descendants to also be treated as having been documented.

If you do not want to document a field, you can mark it as ignored. Doing so prevents it from appearing in the generated snippet while avoiding the failure described above.

You can also document fields in a relaxed mode, where any undocumented fields do not cause a test failure. To do so, use the relaxedRequestPartFields method on org.springframework.restdocs.payload.PayloadDocumentation. This can be useful when documenting a particular scenario where you only want to focus on a subset of the payload of the part.

For further information on describing fields, documenting payloads that use XML, and more, see the section on documenting request and response payloads.

HTTP Headers

You can document the headers in a request or response by using requestHeaders and responseHeaders, respectively. The following examples show how to do so:

MockMvc
this.mockMvc.perform(get("/people").header("Authorization", "Basic dXNlcjpzZWNyZXQ=")) (1)
		.andExpect(status().isOk()).andDo(document("headers", requestHeaders((2)
				headerWithName("Authorization").description("Basic auth credentials")), (3)
				responseHeaders((4)
						headerWithName("X-RateLimit-Limit")
								.description("The total number of requests permitted per period"),
						headerWithName("X-RateLimit-Remaining")
								.description("Remaining requests permitted in current period"),
						headerWithName("X-RateLimit-Reset")
								.description("Time at which the rate limit period will reset"))));
1 Perform a GET request with an Authorization header that uses basic authentication.
2 Configure Spring REST Docs to produce a snippet describing the request’s headers. Uses the static requestHeaders method on org.springframework.restdocs.headers.HeaderDocumentation.
3 Document the Authorization header. Uses the static headerWithName method on org.springframework.restdocs.headers.HeaderDocumentation.
4 Produce a snippet describing the response’s headers. Uses the static responseHeaders method on org.springframework.restdocs.headers.HeaderDocumentation.
WebTestClient
this.webTestClient
	.get().uri("/people").header("Authorization", "Basic dXNlcjpzZWNyZXQ=") (1)
	.exchange().expectStatus().isOk().expectBody()
	.consumeWith(document("headers",
		requestHeaders((2)
			headerWithName("Authorization").description("Basic auth credentials")), (3)
		responseHeaders((4)
			headerWithName("X-RateLimit-Limit")
				.description("The total number of requests permitted per period"),
			headerWithName("X-RateLimit-Remaining")
				.description("Remaining requests permitted in current period"),
			headerWithName("X-RateLimit-Reset")
				.description("Time at which the rate limit period will reset"))));
1 Perform a GET request with an Authorization header that uses basic authentication.
2 Configure Spring REST Docs to produce a snippet describing the request’s headers. Uses the static requestHeaders method on org.springframework.restdocs.headers.HeaderDocumentation.
3 Document the Authorization header. Uses the static headerWithName method on org.springframework.restdocs.headers.HeaderDocumentation.
4 Produce a snippet describing the response’s headers. Uses the static responseHeaders method on org.springframework.restdocs.headers.HeaderDocumentation.
REST Assured
RestAssured.given(this.spec).filter(document("headers", requestHeaders((1)
		headerWithName("Authorization").description("Basic auth credentials")), (2)
		responseHeaders((3)
				headerWithName("X-RateLimit-Limit")
						.description("The total number of requests permitted per period"),
				headerWithName("X-RateLimit-Remaining")
						.description("Remaining requests permitted in current period"),
				headerWithName("X-RateLimit-Reset")
						.description("Time at which the rate limit period will reset"))))
		.header("Authorization", "Basic dXNlcjpzZWNyZXQ=") (4)
		.when().get("/people").then().assertThat().statusCode(is(200));
1 Configure Spring REST Docs to produce a snippet describing the request’s headers. Uses the static requestHeaders method on org.springframework.restdocs.headers.HeaderDocumentation.
2 Document the Authorization header. Uses the static headerWithName method on `org.springframework.restdocs.headers.HeaderDocumentation.
3 Produce a snippet describing the response’s headers. Uses the static responseHeaders method on org.springframework.restdocs.headers.HeaderDocumentation.
4 Configure the request with an Authorization header that uses basic authentication.

The result is a snippet named request-headers.adoc and a snippet named response-headers.adoc. Each contains a table describing the headers.

When documenting HTTP Headers, the test fails if a documented header is not found in the request or response.

HTTP Cookies

You can document the cookies in a request or response by using requestCookies and responseCookies, respectively. The following examples show how to do so:

MockMvc
this.mockMvc.perform(get("/").cookie(new Cookie("JSESSIONID", "ACBCDFD0FF93D5BB"))) (1)
		.andExpect(status().isOk()).andDo(document("cookies", requestCookies((2)
				cookieWithName("JSESSIONID").description("Session token")), (3)
				responseCookies((4)
						cookieWithName("JSESSIONID").description("Updated session token"),
						cookieWithName("logged_in")
								.description("Set to true if the user is currently logged in"))));
1 Make a GET request with a JSESSIONID cookie.
2 Configure Spring REST Docs to produce a snippet describing the request’s cookies. Uses the static requestCookies method on org.springframework.restdocs.cookies.CookieDocumentation.
3 Document the JSESSIONID cookie. Uses the static cookieWithName method on org.springframework.restdocs.cookies.CookieDocumentation.
4 Produce a snippet describing the response’s cookies. Uses the static responseCookies method on org.springframework.restdocs.cookies.CookieDocumentation.
WebTestClient
this.webTestClient.get().uri("/people").cookie("JSESSIONID", "ACBCDFD0FF93D5BB=") (1)
		.exchange().expectStatus().isOk().expectBody().consumeWith(document("cookies", requestCookies((2)
				cookieWithName("JSESSIONID").description("Session token")), (3)
				responseCookies((4)
						cookieWithName("JSESSIONID").description("Updated session token"),
						cookieWithName("logged_in").description("User is logged in"))));
1 Make a GET request with a JSESSIONID cookie.
2 Configure Spring REST Docs to produce a snippet describing the request’s cookies. Uses the static requestCookies method on org.springframework.restdocs.cookies.CookieDocumentation.
3 Document the JSESSIONID cookie. Uses the static cookieWithName method on org.springframework.restdocs.cookies.CookieDocumentation.
4 Produce a snippet describing the response’s cookies. Uses the static responseCookies method on org.springframework.restdocs.cookies.CookieDocumentation.
REST Assured
RestAssured.given(this.spec).filter(document("cookies", requestCookies((1)
		cookieWithName("JSESSIONID").description("Saved session token")), (2)
		responseCookies((3)
				cookieWithName("logged_in").description("If user is logged in"),
				cookieWithName("JSESSIONID").description("Updated session token"))))
		.cookie("JSESSIONID", "ACBCDFD0FF93D5BB") (4)
		.when().get("/people").then().assertThat().statusCode(is(200));
1 Configure Spring REST Docs to produce a snippet describing the request’s cookies. Uses the static requestCookies method on org.springframework.restdocs.cookies.CookieDocumentation.
2 Document the JSESSIONID cookie. Uses the static cookieWithName method on org.springframework.restdocs.cookies.CookieDocumentation.
3 Produce a snippet describing the response’s cookies. Uses the static responseCookies method on org.springframework.restdocs.cookies.CookieDocumentation.
4 Send a JSESSIONID cookie with the request.

The result is a snippet named request-cookies.adoc and a snippet named response-cookies.adoc. Each contains a table describing the cookies.

When documenting HTTP cookies, the test fails if an undocumented cookie is found in the request or response. Similarly, the test also fails if a documented cookie is not found and the cookie has not been marked as optional. You can also document cookies in a relaxed mode, where any undocumented cookies do not cause a test failure. To do so, use the relaxedRequestCookies and relaxedResponseCookies methods on org.springframework.restdocs.cookies.CookieDocumentation. This can be useful when documenting a particular scenario where you only want to focus on a subset of the cookies. If you do not want to document a cookie, you can mark it as ignored. Doing so prevents it from appearing in the generated snippet while avoiding the failure described earlier.

Reusing Snippets

It is common for an API that is being documented to have some features that are common across several of its resources. To avoid repetition when documenting such resources, you can reuse a Snippet configured with the common elements.

First, create the Snippet that describes the common elements. The following example shows how to do so:

protected final LinksSnippet pagingLinks = links(
		linkWithRel("first").optional().description("The first page of results"),
		linkWithRel("last").optional().description("The last page of results"),
		linkWithRel("next").optional().description("The next page of results"),
		linkWithRel("prev").optional().description("The previous page of results"));

Second, use this snippet and add further descriptors that are resource-specific. The following examples show how to do so:

MockMvc
this.mockMvc.perform(get("/").accept(MediaType.APPLICATION_JSON)).andExpect(status().isOk())
		.andDo(document("example", this.pagingLinks.and((1)
				linkWithRel("alpha").description("Link to the alpha resource"),
				linkWithRel("bravo").description("Link to the bravo resource"))));
1 Reuse the pagingLinks Snippet, calling and to add descriptors that are specific to the resource that is being documented.
WebTestClient
this.webTestClient.get().uri("/").accept(MediaType.APPLICATION_JSON).exchange()
	.expectStatus().isOk().expectBody()
	.consumeWith(document("example", this.pagingLinks.and((1)
		linkWithRel("alpha").description("Link to the alpha resource"),
		linkWithRel("bravo").description("Link to the bravo resource"))));
1 Reuse the pagingLinks Snippet, calling and to add descriptors that are specific to the resource that is being documented.
REST Assured
RestAssured.given(this.spec).accept("application/json").filter(document("example", this.pagingLinks.and((1)
		linkWithRel("alpha").description("Link to the alpha resource"),
		linkWithRel("bravo").description("Link to the bravo resource")))).get("/").then().assertThat()
		.statusCode(is(200));
1 Reuse the pagingLinks Snippet, calling and to add descriptors that are specific to the resource that is being documented.

The result of the example is that links with rel values of first, last, next, previous, alpha, and bravo are all documented.

Documenting Constraints

Spring REST Docs provides a number of classes that can help you to document constraints. You can use an instance of ConstraintDescriptions to access descriptions of a class’s constraints. The following example shows how to do so:

public void example() {
	ConstraintDescriptions userConstraints = new ConstraintDescriptions(UserInput.class); (1)
	List<String> descriptions = userConstraints.descriptionsForProperty("name"); (2)
}

static class UserInput {

	@NotNull
	@Size(min = 1)
	String name;

	@NotNull
	@Size(min = 8)
	String password;

}
1 Create an instance of ConstraintDescriptions for the UserInput class.
2 Get the descriptions of the name property’s constraints. This list contains two descriptions: one for the NotNull constraint and one for the Size constraint.

The ApiDocumentation class in the Spring HATEOAS sample shows this functionality in action.

Finding Constraints

By default, constraints are found by using a Bean Validation Validator. Currently, only property constraints are supported. You can customize the Validator that is used by creating ConstraintDescriptions with a custom ValidatorConstraintResolver instance. To take complete control of constraint resolution, you can use your own implementation of ConstraintResolver.

Describing Constraints

Default descriptions are provided for all of Bean Validation 2.0’s constraints:

  • AssertFalse

  • AssertTrue

  • DecimalMax

  • DecimalMin

  • Digits

  • Email

  • Future

  • FutureOrPresent

  • Max

  • Min

  • Negative

  • NegativeOrZero

  • NotBlank

  • NotEmpty

  • NotNull

  • Null

  • Past

  • PastOrPresent

  • Pattern

  • Positive

  • PositiveOrZero

  • Size

Default descriptions are also provided for the following constraints from Hibernate Validator:

  • CodePointLength

  • CreditCardNumber

  • Currency

  • EAN

  • Email

  • Length

  • LuhnCheck

  • Mod10Check

  • Mod11Check

  • NotBlank

  • NotEmpty

  • Currency

  • Range

  • SafeHtml

  • URL

To override the default descriptions or to provide a new description, you can create a resource bundle with a base name of org.springframework.restdocs.constraints.ConstraintDescriptions. The Spring HATEOAS-based sample contains an example of such a resource bundle.

Each key in the resource bundle is the fully-qualified name of a constraint plus a .description. For example, the key for the standard @NotNull constraint is jakarta.validation.constraints.NotNull.description.

You can use a property placeholder referring to a constraint’s attributes in its description. For example, the default description of the @Min constraint, Must be at least ${value}, refers to the constraint’s value attribute.

To take more control of constraint description resolution, you can create ConstraintDescriptions with a custom ResourceBundleConstraintDescriptionResolver. To take complete control, you can create ConstraintDescriptions with a custom ConstraintDescriptionResolver implementation.

Using Constraint Descriptions in Generated Snippets

Once you have a constraint’s descriptions, you are free to use them however you like in the generated snippets. For example, you may want to include the constraint descriptions as part of a field’s description. Alternatively, you could include the constraints as extra information in the request fields snippet. The ApiDocumentation class in the Spring HATEOAS-based sample illustrates the latter approach.

Default Snippets

A number of snippets are produced automatically when you document a request and response.

Snippet Description

curl-request.adoc

Contains the curl command that is equivalent to the MockMvc call that is being documented.

httpie-request.adoc

Contains the HTTPie command that is equivalent to the MockMvc call that is being documented.

http-request.adoc

Contains the HTTP request that is equivalent to the MockMvc call that is being documented.

http-response.adoc

Contains the HTTP response that was returned.

request-body.adoc

Contains the body of the request that was sent.

response-body.adoc

Contains the body of the response that was returned.

You can configure which snippets are produced by default. See the configuration section for more information.

Using Parameterized Output Directories

You can parameterize the output directory used by document. The following parameters are supported:

Parameter Description

{methodName}

The unmodified name of the test method.

{method-name}

The name of the test method, formatted using kebab-case.

{method_name}

The name of the test method, formatted using snake_case.

{ClassName}

The unmodified simple name of the test class.

{class-name}

The simple name of the test class, formatted using kebab-case.

{class_name}

The simple name of the test class, formatted using snake_case.

{step}

The count of calls made to the service in the current test.

For example, document("{class-name}/{method-name}") in a test method named creatingANote on the test class GettingStartedDocumentation writes snippets into a directory named getting-started-documentation/creating-a-note.

A parameterized output directory is particularly useful in combination with a @Before method. It lets documentation be configured once in a setup method and then reused in every test in the class. The following examples show how to do so:

MockMvc
@Before
public void setUp() {
	this.mockMvc = MockMvcBuilders.webAppContextSetup(this.context)
			.apply(documentationConfiguration(this.restDocumentation)).alwaysDo(document("{method-name}/{step}/"))
			.build();
}
REST Assured
@Before
public void setUp() {
	this.spec = new RequestSpecBuilder().addFilter(documentationConfiguration(this.restDocumentation))
			.addFilter(document("{method-name}/{step}")).build();
}
WebTestClient
@Before
public void setUp() {
	this.webTestClient = WebTestClient.bindToApplicationContext(this.context).configureClient()
			.filter(documentationConfiguration(this.restDocumentation))
			.entityExchangeResultConsumer(document("{method-name}/{step}")).build();
}

With this configuration in place, every call to the service you are testing produces the default snippets without any further configuration. Take a look at the GettingStartedDocumentation classes in each of the sample applications to see this functionality in action.

Customizing the Output

This section describes how to customize the output of Spring REST Docs.

Customizing the Generated Snippets

Spring REST Docs uses Mustache templates to produce the generated snippets. Default templates are provided for each of the snippets that Spring REST Docs can produce. To customize a snippet’s content, you can provide your own template.

Templates are loaded from the classpath from an org.springframework.restdocs.templates subpackage. The name of the subpackage is determined by the ID of the template format that is in use. The default template format, Asciidoctor, has an ID of asciidoctor, so snippets are loaded from org.springframework.restdocs.templates.asciidoctor. Each template is named after the snippet that it produces. For example, to override the template for the curl-request.adoc snippet, create a template named curl-request.snippet in src/test/resources/org/springframework/restdocs/templates/asciidoctor.

Including Extra Information

There are two ways to provide extra information for inclusion in a generated snippet:

  • Use the attributes method on a descriptor to add one or more attributes to it.

  • Pass in some attributes when calling curlRequest, httpRequest, httpResponse, and so on. Such attributes are associated with the snippet as a whole.

Any additional attributes are made available during the template rendering process. Coupled with a custom snippet template, this makes it possible to include extra information in a generated snippet.

A concrete example is the addition of a constraints column and a title when documenting request fields. The first step is to provide a constraints attribute for each field that you document and to provide a title attribute. The following examples show how to do so:

MockMvc
.andDo(document("create-user", requestFields(attributes(key("title").value("Fields for user creation")), (1)
		fieldWithPath("name").description("The user's name")
				.attributes(key("constraints").value("Must not be null. Must not be empty")), (2)
		fieldWithPath("email").description("The user's email address")
				.attributes(key("constraints").value("Must be a valid email address"))))); (3)
1 Configure the title attribute for the request fields snippet.
2 Set the constraints attribute for the name field.
3 Set the constraints attribute for the email field.
WebTestClient
.consumeWith(document("create-user",
	requestFields(
		attributes(key("title").value("Fields for user creation")), (1)
		fieldWithPath("name")
			.description("The user's name")
			.attributes(key("constraints").value("Must not be null. Must not be empty")), (2)
		fieldWithPath("email")
			.description("The user's email address")
			.attributes(key("constraints").value("Must be a valid email address"))))); (3)
1 Configure the title attribute for the request fields snippet.
2 Set the constraints attribute for the name field.
3 Set the constraints attribute for the email field.
REST Assured
.filter(document("create-user",
		requestFields(attributes(key("title").value("Fields for user creation")), (1)
				fieldWithPath("name").description("The user's name")
						.attributes(key("constraints").value("Must not be null. Must not be empty")), (2)
				fieldWithPath("email").description("The user's email address")
						.attributes(key("constraints").value("Must be a valid email address"))))) (3)
1 Configure the title attribute for the request fields snippet.
2 Set the constraints attribute for the name field.
3 Set the constraints attribute for the email field.

The second step is to provide a custom template named request-fields.snippet that includes the information about the fields' constraints in the generated snippet’s table and adds a title.

.{{title}} (1)
|===
|Path|Type|Description|Constraints (2)

{{#fields}}
|{{path}}
|{{type}}
|{{description}}
|{{constraints}} (3)

{{/fields}}
|===
1 Add a title to the table.
2 Add a new column named "Constraints".
3 Include the descriptors' constraints attribute in each row of the table.

Customizing requests and responses

There may be situations where you do not want to document a request exactly as it was sent or a response exactly as it was received. Spring REST Docs provides a number of preprocessors that can be used to modify a request or response before it is documented.

Preprocessing is configured by calling document with an OperationRequestPreprocessor or an OperationResponsePreprocessor. You can obtain instances by using the static preprocessRequest and preprocessResponse methods on Preprocessors. The following examples show how to do so:

MockMvc
this.mockMvc.perform(get("/")).andExpect(status().isOk())
		.andDo(document("index", preprocessRequest(modifyHeaders().remove("Foo")), (1)
				preprocessResponse(prettyPrint()))); (2)
1 Apply a request preprocessor that removes the header named Foo.
2 Apply a response preprocessor that pretty prints its content.
WebTestClient
this.webTestClient.get().uri("/").exchange().expectStatus().isOk().expectBody()
	.consumeWith(document("index",
		preprocessRequest(modifyHeaders().remove("Foo")), (1)
		preprocessResponse(prettyPrint()))); (2)
1 Apply a request preprocessor that removes the header named Foo.
2 Apply a response preprocessor that pretty prints its content.
REST Assured
RestAssured.given(this.spec).filter(document("index", preprocessRequest(modifyHeaders().remove("Foo")), (1)
		preprocessResponse(prettyPrint()))) (2)
		.when().get("/").then().assertThat().statusCode(is(200));
1 Apply a request preprocessor that removes the header named Foo.
2 Apply a response preprocessor that pretty prints its content.

Alternatively, you may want to apply the same preprocessors to every test. You can do so by using the RestDocumentationConfigurer API in your @Before method to configure the preprocessors. For example, to remove the Foo header from all requests and pretty print all responses, you could do one of the following (depending on your testing environment):

MockMvc
private MockMvc mockMvc;

@Before
public void setup() {
	this.mockMvc = MockMvcBuilders.webAppContextSetup(this.context)
			.apply(documentationConfiguration(this.restDocumentation).operationPreprocessors()
					.withRequestDefaults(modifyHeaders().remove("Foo")) (1)
					.withResponseDefaults(prettyPrint())) (2)
			.build();
}
1 Apply a request preprocessor that removes the header named Foo.
2 Apply a response preprocessor that pretty prints its content.
WebTestClient
private WebTestClient webTestClient;

@Before
public void setup() {
	this.webTestClient = WebTestClient.bindToApplicationContext(this.context)
		.configureClient()
		.filter(documentationConfiguration(this.restDocumentation)
			.operationPreprocessors()
				.withRequestDefaults(modifyHeaders().remove("Foo")) (1)
				.withResponseDefaults(prettyPrint())) (2)
		.build();
}
1 Apply a request preprocessor that removes the header named Foo.
2 Apply a response preprocessor that pretty prints its content.
REST Assured
private RequestSpecification spec;

@Before
public void setup() {
	this.spec = new RequestSpecBuilder()
			.addFilter(documentationConfiguration(this.restDocumentation).operationPreprocessors()
					.withRequestDefaults(modifyHeaders().remove("Foo")) (1)
					.withResponseDefaults(prettyPrint())) (2)
			.build();
}
1 Apply a request preprocessor that removes the header named Foo.
2 Apply a response preprocessor that pretty prints its content.

Then, in each test, you can perform any configuration specific to that test. The following examples show how to do so:

MockMvc
this.mockMvc.perform(get("/")).andExpect(status().isOk())
		.andDo(document("index", links(linkWithRel("self").description("Canonical self link"))));
WebTestClient
this.webTestClient.get().uri("/").exchange().expectStatus().isOk()
	.expectBody().consumeWith(document("index",
		links(linkWithRel("self").description("Canonical self link"))));
REST Assured
RestAssured.given(this.spec)
		.filter(document("index", links(linkWithRel("self").description("Canonical self link")))).when()
		.get("/").then().assertThat().statusCode(is(200));

Various built-in preprocessors, including those illustrated above, are available through the static methods on Preprocessors. See below for further details.

Preprocessors

Pretty Printing

prettyPrint on Preprocessors formats the content of the request or response to make it easier to read.

If you are documenting a hypermedia-based API, you may want to encourage clients to navigate the API by using links rather than through the use of hard coded URIs. One way to do so is to limit the use of URIs in the documentation. maskLinks on Preprocessors replaces the href of any links in the response with …​. You can also specify a different replacement if you wish.

Modifying Headers

You can use modifyHeaders on Preprocessors to add, set, and remove request or response headers.

Replacing Patterns

replacePattern on Preprocessors provides a general purpose mechanism for replacing content in a request or response. Any occurrences that match a regular expression are replaced.

Modifying Request Parameters

You can use modifyParameters on Preprocessors to add, set, and remove request parameters.

Modifying URIs

If you use MockMvc or a WebTestClient that is not bound to a server, you should customize URIs by changing the configuration.

You can use modifyUris on Preprocessors to modify any URIs in a request or a response. When using REST Assured or WebTestClient bound to a server, this lets you customize the URIs that appear in the documentation while testing a local instance of the service.

Writing Your Own Preprocessor

If one of the built-in preprocessors does not meet your needs, you can write your own by implementing the OperationPreprocessor interface. You can then use your custom preprocessor in exactly the same way as any of the built-in preprocessors.

If you want to modify only the content (body) of a request or response, consider implementing the ContentModifier interface and using it with the built-in ContentModifyingOperationPreprocessor.

Configuration

This section covers how to configure Spring REST Docs.

Documented URIs

This section covers configuring documented URIs.

MockMvc URI Customization

When using MockMvc, the default configuration for URIs documented by Spring REST Docs is as follows:

Setting Default

Scheme

http

Host

localhost

Port

8080

This configuration is applied by MockMvcRestDocumentationConfigurer. You can use its API to change one or more of the defaults to suit your needs. The following example shows how to do so:

this.mockMvc = MockMvcBuilders.webAppContextSetup(this.context)
		.apply(documentationConfiguration(this.restDocumentation).uris().withScheme("https")
				.withHost("example.com").withPort(443))
		.build();
If the port is set to the default for the configured scheme (port 80 for HTTP or port 443 for HTTPS), it is omitted from any URIs in the generated snippets.
To configure a request’s context path, use the contextPath method on MockHttpServletRequestBuilder.

REST Assured URI Customization

REST Assured tests a service by making actual HTTP requests. As a result, URIs must be customized once the operation on the service has been performed but before it is documented. A REST-Assured-specific preprocessor is provided for this purpose.

WebTestClient URI Customization

When using WebTestClient, the default base for URIs documented by Spring REST Docs is http://localhost:8080. You can customize this base by using the baseUrl(String) method on WebTestClient.Builder. The following example shows how to do so:

@Before
public void setUp() {
	this.webTestClient = WebTestClient.bindToApplicationContext(this.context).configureClient()
			.baseUrl("https://api.example.com") (1)
			.filter(documentationConfiguration(this.restDocumentation)).build();
}
1 Configure the base of documented URIs to be https://api.example.com.

Snippet Encoding

The default snippet encoding is UTF-8. You can change the default snippet encoding by using the RestDocumentationConfigurer API. For example, the following examples use ISO-8859-1:

MockMvc
this.mockMvc = MockMvcBuilders.webAppContextSetup(this.context)
		.apply(documentationConfiguration(this.restDocumentation).snippets().withEncoding("ISO-8859-1"))
		.build();
WebTestClient
this.webTestClient = WebTestClient.bindToApplicationContext(this.context).configureClient()
	.filter(documentationConfiguration(this.restDocumentation)
		.snippets().withEncoding("ISO-8859-1"))
	.build();
REST Assured
this.spec = new RequestSpecBuilder()
		.addFilter(documentationConfiguration(this.restDocumentation).snippets().withEncoding("ISO-8859-1"))
		.build();
When Spring REST Docs converts the content of a request or a response to a String, the charset specified in the Content-Type header is used if it is available. In its absence, the JVM’s default Charset is used. You can configure the JVM’s default Charset by using the file.encoding system property.

Snippet Template Format

The default snippet template format is Asciidoctor. Markdown is also supported out of the box. You can change the default format by using the RestDocumentationConfigurer API. The following examples show how to do so:

MockMvc
this.mockMvc = MockMvcBuilders.webAppContextSetup(this.context)
		.apply(documentationConfiguration(this.restDocumentation).snippets()
				.withTemplateFormat(TemplateFormats.markdown()))
		.build();
WebTestClient
this.webTestClient = WebTestClient.bindToApplicationContext(this.context).configureClient()
	.filter(documentationConfiguration(this.restDocumentation)
		.snippets().withTemplateFormat(TemplateFormats.markdown()))
	.build();
REST Assured
this.spec = new RequestSpecBuilder().addFilter(documentationConfiguration(this.restDocumentation).snippets()
		.withTemplateFormat(TemplateFormats.markdown())).build();

Default Snippets

Six snippets are produced by default:

  • curl-request

  • http-request

  • http-response

  • httpie-request

  • request-body

  • response-body

You can change the default snippet configuration during setup by using the RestDocumentationConfigurer API. The following examples produce only the curl-request snippet by default:

MockMvc
this.mockMvc = MockMvcBuilders.webAppContextSetup(this.context)
		.apply(documentationConfiguration(this.restDocumentation).snippets().withDefaults(curlRequest()))
		.build();
WebTestClient
this.webTestClient = WebTestClient.bindToApplicationContext(this.context)
	.configureClient().filter(
		documentationConfiguration(this.restDocumentation)
			.snippets().withDefaults(curlRequest()))
	.build();
REST Assured
this.spec = new RequestSpecBuilder()
		.addFilter(documentationConfiguration(this.restDocumentation).snippets().withDefaults(curlRequest()))
		.build();

Default Operation Preprocessors

You can configure default request and response preprocessors during setup by using the RestDocumentationConfigurer API. The following examples remove the Foo headers from all requests and pretty print all responses:

MockMvc
this.mockMvc = MockMvcBuilders.webAppContextSetup(this.context)
		.apply(documentationConfiguration(this.restDocumentation).operationPreprocessors()
				.withRequestDefaults(modifyHeaders().remove("Foo")) (1)
				.withResponseDefaults(prettyPrint())) (2)
		.build();
1 Apply a request preprocessor that removes the header named Foo.
2 Apply a response preprocessor that pretty prints its content.
WebTestClient
this.webTestClient = WebTestClient.bindToApplicationContext(this.context)
	.configureClient()
	.filter(documentationConfiguration(this.restDocumentation)
		.operationPreprocessors()
			.withRequestDefaults(modifyHeaders().remove("Foo")) (1)
			.withResponseDefaults(prettyPrint())) (2)
	.build();
1 Apply a request preprocessor that removes the header named Foo.
2 Apply a response preprocessor that pretty prints its content.
REST Assured
this.spec = new RequestSpecBuilder()
		.addFilter(documentationConfiguration(this.restDocumentation).operationPreprocessors()
				.withRequestDefaults(modifyHeaders().remove("Foo")) (1)
				.withResponseDefaults(prettyPrint())) (2)
		.build();
1 Apply a request preprocessor that removes the header named Foo.
2 Apply a response preprocessor that pretty prints its content.

Working with Asciidoctor

This section describes the aspects of working with Asciidoctor that are particularly relevant to Spring REST Docs.

Asciidoc is the document format. Asciidoctor is the tool that produces content (usually as HTML) from Asciidoc files (which end with .adoc).

Resources

Including Snippets

This section covers how to include Asciidoc snippets.

Including Multiple Snippets for an Operation

You can use a macro named operation to import all or some of the snippets that have been generated for a specific operation. It is made available by including spring-restdocs-asciidoctor in your project’s build configuration.

The target of the macro is the name of the operation. In its simplest form, you can use the macro to include all of the snippets for an operation, as shown in the following example:

operation::index[]

You can use the operation macro also supports a snippets attribute. The snippets attribute to select the snippets that should be included. The attribute’s value is a comma-separated list. Each entry in the list should be the name of a snippet file (minus the .adoc suffix) to include. For example, only the curl, HTTP request, and HTTP response snippets can be included, as shown in the following example:

operation::index[snippets='curl-request,http-request,http-response']

The preceding example is the equivalent of the following:

[[example_curl_request]]
== Curl request

include::{snippets}/index/curl-request.adoc[]

[[example_http_request]]
== HTTP request

include::{snippets}/index/http-request.adoc[]

[[example_http_response]]
== HTTP response

include::{snippets}/index/http-response.adoc[]
Section Titles

For each snippet that is included by using the operation macro, a section with a title is created. Default titles are provided for the following built-in snippets:

Snippet Title

curl-request

Curl Request

http-request

HTTP request

http-response

HTTP response

httpie-request

HTTPie request

links

Links

request-body

Request body

request-fields

Request fields

response-body

Response body

response-fields

Response fields

For snippets not listed in the preceding table, a default title is generated by replacing - characters with spaces and capitalizing the first letter. For example, the title for a snippet named custom-snippet will be “Custom snippet”.

You can customize the default titles by using document attributes. The name of the attribute should be operation-{snippet}-title. For example, to customize the title of the curl-request snippet to be "Example request", you can use the following attribute:

:operation-curl-request-title: Example request

Including Individual Snippets

The include macro is used to include individual snippets in your documentation. You can use the snippets attribute (which is automatically set by spring-restdocs-asciidoctor configured in the build configuration) to reference the snippets output directory. The following example shows how to do so:

include::{snippets}/index/curl-request.adoc[]

Customizing Tables

Many of the snippets contain a table in its default configuration. The appearance of the table can be customized, either by providing some additional configuration when the snippet is included or by using a custom snippet template.

Formatting Columns

Asciidoctor has rich support for formatting a table’s columns. As the following example shows, you can specify the widths of a table’s columns by using the cols attribute:

[cols="1,3"] (1)
include::{snippets}/index/links.adoc[]
1 The table’s width is split across its two columns, with the second column being three times as wide as the first.

Configuring the Title

You can specify the title of a table by using a line prefixed by a .. The following example shows how to do so:

.Links (1)
include::{snippets}/index/links.adoc[]
1 The table’s title will be Links.

Avoiding Table Formatting Problems

Asciidoctor uses the | character to delimit cells in a table. This can cause problems if you want a | to appear in a cell’s contents. You can avoid the problem by escaping the | with a backslash — in other words, by using \| rather than |.

All of the default Asciidoctor snippet templates perform this escaping automatically by using a Mustache lamba named tableCellContent. If you write your own custom templates you may want to use this lamba. The following example shows how to escape | characters in a cell that contains the value of a description attribute:

| {{#tableCellContent}}{{description}}{{/tableCellContent}}

Further Reading

See the Tables section of the Asciidoctor user manual for more information about customizing tables.

Working with Markdown

This section describes the aspects of working with Markdown that are particularly relevant to Spring REST Docs.

Limitations

Markdown was originally designed for people writing for the web and, as such, is not as well-suited to writing documentation as Asciidoctor. Typically, these limitations are overcome by using another tool that builds on top of Markdown.

Markdown has no official support for tables. Spring REST Docs' default Markdown snippet templates use Markdown Extra’s table format.

Including Snippets

Markdown has no built-in support for including one Markdown file in another. To include the generated snippets of Markdown in your documentation, you should use an additional tool that supports this functionality. One example that is particularly well-suited to documenting APIs is Slate.

Contributing

Spring REST Docs is intended to make it easy for you to produce high-quality documentation for your RESTful services. However, we cannot achieve that goal without your contributions.

Questions

You can ask questions about Spring REST Docs on Stack Overflow by using the spring-restdocs tag. Similarly, we encourage you to help your fellow Spring REST Docs users by answering questions.

Bugs

If you believe you have found a bug, please take a moment to search the existing issues. If no one else has reported the problem, please open a new issue that describes the problem in detail and, ideally, includes a test that reproduces it.

Enhancements

If you would like an enhancement to be made to Spring REST Docs, pull requests are most welcome. The source code is on GitHub. You may want to search the existing issues and pull requests to see if the enhancement has already been proposed. You may also want to open a new issue to discuss a possible enhancement before work on it begins.