This is an extension that adds API specifications as an output format to Spring REST Docs. It currently supports:
- OpenAPI 2.0 in
json
andyaml
- OpenAPI 3.0.1 in
json
andyaml
- Postman Collections 2.1.0
Please note that this extension was developed for JSON-based APIs. We do not expect this extension to build usable API specification for non-JSON request or response bodies.
Spring REST Docs is a great tool to produce documentation for your RESTful services that is accurate and readable.
We especially like its test-driven approach and this is the main reason why we chose it.
It offers support for AsciiDoc and Markdown. This is great for generating simple HTML-based documentation. But both are markup languages and thus it is hard to get any further than statically generated HTML.
API specifications like OpenAPI are a lot more flexible. With e.g. OpenAPI you get a machine-readable description of your API. There is a rich ecosystem around it that contains tools to:
- generate a HTML representation of your API - ReDoc
- generate an interactive API reference - e.g. using services like stoplight.io or readme.io
Also, API specifications like OpenAPI are supported by many REST clients like Postman and Paw. Thus having an API specification for a REST API is a great plus when starting to work with it.
The most common use case to generate an OpenAPI specification is code introspection and adding documentation related annotations to your code. We do not like enriching our production code with this information and clutter it with even more annotations. We agree with Spring REST Docs that the test-driven way to produce accurate API documentation is the way to go. This is why we came up with this project.
- Motivation
- Getting started
- Generate an HTML-based API reference from OpenAPI
- RAML
The project consists of the following main components:
- restdocs-api-spec - contains the actual Spring REST Docs extension.
This is most importantly the ResourceDocumentation which is the entrypoint to use the extension in your tests.
The ResourceSnippet is the snippet used to produce a json file
resource.json
containing all the details about the documented resource. - restdocs-api-spec-mockmvc - contains a wrapper for
MockMvcRestDocumentation
for easier migration torestdocs-api-spec
from MockMvc tests that use plainspring-rest-docs-mockmvc
. - restdocs-api-spec-restassured - contains a wrapper for
RestAssuredRestDocumentation
for easier migration torestdocs-api-spec
from Rest Assured tests that use plainspring-rest-docs-restassured
. - restdocs-api-spec-gradle-plugin - adds a gradle plugin that aggregates the
resource.json
files produced byResourceSnippet
into an API specification file for the whole project.
- Add the plugin
- Using the plugins DSL:
Examples with Kotlin are also available here
plugins { id 'com.epages.restdocs-api-spec' version '0.16.0' }
- OR Using legacy plugin application:
- 1.1 Use of
buildscript
requires you to add thehttps://plugins.gradle.org/m2/
repository. - 1.2 add the dependency to
restdocs-api-spec-gradle-plugin
- 1.3 apply
restdocs-api-spec-gradle-plugin
buildscript { repositories { maven { url "https://plugins.gradle.org/m2/" //1.1 } } dependencies { classpath "com.epages:restdocs-api-spec-gradle-plugin:0.16.0" //1.2 } } apply plugin: 'com.epages.restdocs-api-spec' //1.3
- 1.1 Use of
- Using the plugins DSL:
- Add required dependencies to your tests
- 2.1 add the
mavenCentral
repository used to resolve thecom.epages:restdocs-api-spec
module of the project. - 2.2 add the actual
restdocs-api-spec-mockmvc
dependency to the test scope. Userestdocs-api-spec-restassured
if you useRestAssured
instead ofMockMvc
. - 2.3 add configuration options for restdocs-api-spec-gradle-plugin`. See Gradle plugin configuration
repositories { //2.1 mavenCentral() } dependencies { //.. testImplementation('com.epages:restdocs-api-spec-mockmvc:0.16.0') //2.2 } openapi { //2.3 host = 'localhost:8080' basePath = '/api' title = 'My API' description = 'My API description' tagDescriptionsPropertiesFile = 'src/docs/tag-descriptions.yaml' version = '1.0.0' format = 'json' } openapi3 { server = 'https://localhost:8080' title = 'My API' description = 'My API description' tagDescriptionsPropertiesFile = 'src/docs/tag-descriptions.yaml' version = '0.1.0' format = 'yaml' } postman { title = 'My API' version = '0.1.0' baseUrl = 'https://localhost:8080' }
- 2.1 add the
See the build.gradle for the setup used in the sample project.
The root project does not provide a maven plugin.
But you can find a plugin that works with restdocs-api-spec
at BerkleyTechnologyServices/restdocs-spec.
The class ResourceDocumentation contains the entry point for using the ResourceSnippet.
The most basic form does not take any parameters:
mockMvc
.perform(post("/carts"))
.andDo(document("carts-create", resource("Create a cart")));
This test will produce the resource.json
file in the snippets directory.
This file just contains all the information that we can collect about the resource.
The format of this file is not specific to an API specification.
{
"operationId" : "carts-create",
"summary" : "Create a cart",
"description" : "Create a cart",
"privateResource" : false,
"deprecated" : false,
"request" : {
"path" : "/carts",
"method" : "POST",
"contentType" : null,
"headers" : [ ],
"pathParameters" : [ ],
"requestParameters" : [ ],
"requestFields" : [ ],
"example" : null,
"securityRequirements" : null
},
"response" : {
"status" : 201,
"contentType" : "application/hal+json",
"headers" : [ ],
"responseFields" : [ ],
"example" : "{\n \"total\" : 0,\n \"products\" : [ ],\n \"_links\" : {\n \"self\" : {\n \"href\" : \"http://localhost:8080/carts/4\"\n },\n \"order\" : {\n \"href\" : \"http://localhost:8080/carts/4/order\"\n }\n }\n}"
}
}
Just like with Spring REST Docs we can also describe request fields, response fields, path variables, parameters, headers, and links.
Furthermore you can add a text description and a summary for your resource.
The extension also discovers JWT
tokens in the Authorization
header and will document the required scopes from it. Also basic auth headers are discovered and documented.
The following example uses ResourceSnippetParameters
to document response fields, path parameters, and links.
We paid close attention to keep the API as similar as possible to what you already know from Spring REST Docs.
fieldWithPath
and linkWithRel
are actually still the static methods you would use in your using Spring REST Docs test.
mockMvc.perform(get("/carts/{id}", cartId)
.accept(HAL_JSON))
.andExpect(status().isOk())
.andDo(document("cart-get",
resource(ResourceSnippetParameters.builder()
.description("Get a cart by id")
.pathParameters(
parameterWithName("id").description("the cart id"))
.responseFields(
fieldWithPath("total").description("Total amount of the cart."),
fieldWithPath("products").description("The product line item of the cart."),
subsectionWithPath("products[]._links.product").description("Link to the product."),
fieldWithPath("products[].quantity").description("The quantity of the line item."),
subsectionWithPath("products[].product").description("The product the line item relates to."),
subsectionWithPath("_links").description("Links section."))
.links(
linkWithRel("self").ignored(),
linkWithRel("order").description("Link to order the cart."))
.build())));
Please see the CartIntegrationTest in the sample application for a detailed example.
template URIs
to refer to path variables in your request
Note how we use the urlTemplate
to build the request with RestDocumentationRequestBuilders
.
This makes the urlTemplate
available in the snippet and we can depend on the non-expanded template when generating the OpenAPI file.
mockMvc.perform(get("/carts/{id}", cartId)
Similar to the way Spring REST Docs allows to use bean validation constraints to enhance your documentation, you can also use the constraints from your model classes to let restdocs-api-spec
enrich the generated JsonSchemas.
restdocs-api-spec
provides the class com.epages.restdocs.apispec.ConstrainedFields to generate FieldDescriptor
s that contain information about the constraints on this field.
Currently the following constraints are considered when generating JsonSchema from FieldDescriptor
s that have been created via com.epages.restdocs.apispec.ConstrainedFields
NotNull
,NotEmpty
, andNotBlank
annotated fields become required fields in the JsonSchema- for String fields annotated with
NotEmpty
, andNotBlank
theminLength
constraint in JsonSchema is set to 1 - for String fields annotated with
Length
theminLength
andmaxLength
constraints in JsonSchema are set to the value of the corresponding attribute of the annotation - for String fields annotated with
Pattern
, the pattern constraint is propagated to JsonSchema - for Number fields annotated with
Min
, theminimum
constraint is propagated to JsonSchema - for Number fields annotated with
Max
, themaximum
constraint is propagated to JsonSchema - for Number fields annotated with
Size
theminimum
andmaximum
constraints in JsonSchema are set to the value of the corresponding attribute of the annotation
If you already have your own ConstraintFields
implementation you can also add the logic from com.epages.restdocs.apispec.ConstrainedFields
to your own class.
Here it is important to add the constraints under the key validationConstraints
into the attributes map if the FieldDescriptor
.
For convenience when applying restdocs-api-spec
to an existing project that uses Spring REST Docs, we introduced com.epages.restdocs.apispec.MockMvcRestDocumentationWrapper.
In your tests you can just replace calls to MockMvcRestDocumentation.document
with the corresponding variant of MockMvcRestDocumentationWrapper.document
.
MockMvcRestDocumentationWrapper.document
will execute the specified snippets and also add a ResourceSnippet
equipped with the input from your snippets.
Here is an example:
resultActions
.andDo(
MockMvcRestDocumentationWrapper.document(operationName,
requestFields(fieldDescriptors().getFieldDescriptors()),
responseFields(
fieldWithPath("comment").description("the comment"),
fieldWithPath("flag").description("the flag"),
fieldWithPath("count").description("the count"),
fieldWithPath("id").description("id"),
fieldWithPath("_links").ignored()
),
links(linkWithRel("self").description("some"))
)
);
This will do exactly what MockMvcRestDocumentation.document
does.
Additionally it will add a ResourceSnippet
with the descriptors you provided in the RequestFieldsSnippet
, ResponseFieldsSnippet
, and LinksSnippet
.
Also for REST Assured we offer a convenience wrapper similar to MockMvcRestDocumentationWrapper
.
The usage for REST Assured is also similar to MockMVC, except that com.epages.restdocs.apispec.RestAssuredRestDocumentationWrapper is used instead of com.epages.restdocs.apispec.MockMvcRestDocumentationWrapper.
To use the RestAssuredRestDocumentationWrapper
, you have to add a dependency to restdocs-api-spec-restassured to your build.
RestAssured.given(this.spec)
.filter(RestAssuredRestDocumentationWrapper.document("{method-name}",
"The API description",
requestParameters(
parameterWithName("param").description("the param")
),
responseFields(
fieldWithPath("doc.timestamp").description("Creation timestamp")
)
))
.when()
.queryParam("param", "foo")
.get("/restAssuredExample")
.then()
.statusCode(200);
We also offer a convenience wrapper for WebTestClient
which works similar to MockMvcRestDocumentationWrapper
.
The usage is similar to MockMVC, except that com.epages.restdocs.apispec.WebTestClientRestDocumentationWrapper is used instead of com.epages.restdocs.apispec.MockMvcRestDocumentationWrapper.
To use the WebTestClientRestDocumentationWrapper
, you will have to add a dependency to restdocs-api-spec-webtestclient to your build.
webTestClient.get().uri("/sample/{id}?queryParam=something", "1024").exchange()
.expectStatus().isOk().expectBody()
.consumeWith(
WebTestClientRestDocumentationWrapper
.document("sample",
RequestDocumentation.pathParameters(
parameterWithName("id").description(
"description of the path parameter")
),
RequestDocumentation.requestParameters(
parameterWithName("queryParam").description(
"description of the query parameter")
),
HeaderDocumentation.responseHeaders(
headerWithName(HttpHeaders.CONTENT_TYPE)
.description(MediaType.APPLICATION_JSON_UTF8_VALUE)
),
responseFields(
PayloadDocumentation.fieldWithPath("field1").type(JsonFieldType.STRING)
.description("description of field1"),
PayloadDocumentation.fieldWithPath("field2").type(JsonFieldType.STRING)
.description("description of field2")
)
)
);
The project has limited support for describing security requirements of an API. Currently we only support Oauth2 with JWT tokens and HTTP Basic Auth.
restdocs-api-spec
inspects the AUTHORIZATION
header of a request for a JWT
token.
Also the a HTTP basic authorization header is discovered and documented.
If such a token is found the scopes are extracted and added to the resource.json
snippet.
The restdocs-api-spec-gradle-plugin
will consider this information if the oauth2SecuritySchemeDefinition
configuration option is set (see Gradle plugin configuration).
This will result in a top-level securityDefinitions
in the OpenAPI definition.
Additionally the required scopes will be added in the security
section of an operation
.
restdocs-api-spec-gradle-plugin
is responsible for picking up the generated resource.json
files and aggregate them into an API specification.
In order to generate an OpenAPI 2.0 specification we use the openapi
task:
./gradlew openapi
In order to generate an OpenAPI 3.0.1 specification we use the openapi3
task:
./gradlew openapi3
For our sample project this creates a openapi3.yaml
file in the output directory (build/api-spec
).
In order to generate a Postman collection we use the postman
task:
./gradlew postman
For our sample project this creates a postman-collection.json
file in the output directory (build/api-spec
).
Name | Description | Default value |
---|---|---|
separatePublicApi | Should the plugin generate additional API specification files which do not contain the resources marked as private | false |
outputDirectory | The output directory for the API specification files | build/api-spec |
snippetsDirectory | The directory Spring REST Docs generated the snippets to | build/generated-snippets |
The restdocs-api-spec-gradle-plugin
takes the following configuration options for OpenAPI 2.0 and OpenAPI 3.0.1 - all are optional.
Name | Description | Default value |
---|---|---|
title | The title of the application. Used for the title attribute in the Info object |
API documentation |
description | A description of the application. Used for the description attribute in the Info object |
empty |
version | The version of the api. Used for the version attribute in the Info object |
project version |
format | The format of the output OpenAPI file - supported values are json and yaml |
json |
tagDescriptionsPropertiesFile | A yaml file mapping tag names to descriptions. These are populated into the top level ` Tags attribute | no default - if not provided no tags created. |
oauth2SecuritySchemeDefinition | Closure containing information to generate the securityDefinitions object in the OpenAPI specification. |
empty |
oauth2SecuritySchemeDefinition.flows | The Oauth2 flows the API supports. Use valid values from the securityDefinitions specification. | no default - required if oauth2SecuritySchemeDefinition is set. |
oauth2SecuritySchemeDefinition.tokenUrl | The Oauth2 tokenUrl | no default - required for the flows password , application , accessCode . |
oauth2SecuritySchemeDefinition.authorizationUrl | The Oauth2 authorizationUrl | no default - required for the flows implicit , accessCode . |
oauth2SecuritySchemeDefinition.scopeDescriptionsPropertiesFile | A yaml file mapping scope names to descriptions. These are used in the securityDefinitions as the scope description |
no default - if not provided the scope descriptions default to No description . |
The scopeDescriptionsPropertiesFile
is supposed to be a yaml file:
scope-name: A description
The restdocs-api-spec-gradle-plugin
takes the following configuration options for OpenAPI 2.0 - all are optional.
Name | Description | Default value |
---|---|---|
host | The host serving the API - corresponds to the attribute with the same name in the OpenAPI root object | localhost |
basePath | The base path on which the API is served - corresponds to the attribute with the same name in the OpenAPI root object | null |
schemes | The supported transfer protocols of the API - corresponds to the attribute with the same name in the OpenAPI root object | ['http'"] |
outputFileNamePrefix | The file name prefix of the output file. | openapi which results in e.g. openapi.json for the format json |
Example configuration closure:
openapi {
basePath = "/api"
host = "api-shop.beyondshop.cloud"
schemes = ["https"]
format = "yaml"
title = 'Beyond REST API'
version = "1.0.0"
separatePublicApi = true
snippetsDirectory="src/docs/asciidoc/generated-snippets/"
outputDirectory="openapi/"
oauth2SecuritySchemeDefinition = {
flows = ['accessCode', 'application']
tokenUrl = 'https://api-shop.beyondshop.cloud/api/oauth/token'
authorizationUrl = 'https://api-shop.beyondshop.cloud/api/auth/oauth-ext/authorize'
scopeDescriptionsPropertiesFile = "src/docs/scope-descriptions.yaml"
}
}
The restdocs-api-spec-gradle-plugin
takes the following configuration options for OpenAPI 3.0.1 - all are optional.
Name | Description | Default value |
---|---|---|
outputFileNamePrefix | The file name prefix of the output file. | openapi3 which results in e.g. openapi3.json for the format json |
servers | Specifies the servers the API is available from. Use this property to specify multiple server definitions. See example below. | http://localhost |
server | Specifies the servers the API is available from. Use this property to specify just a single server definition. See example below | http://localhost |
Example configuration closure:
openapi3 {
servers = [ { url = "http://some.api" } ]
title = 'My API title'
version = '1.0.1'
format = 'yaml'
separatePublicApi = true
outputFileNamePrefix = 'my-api-spec'
oauth2SecuritySchemeDefinition = {
flows = ['authorizationCode']
tokenUrl = 'http://example.com/token'
authorizationUrl = 'http://example.com/authorize'
scopeDescriptionsPropertiesFile = "scopeDescriptions.yaml"
}
}
Example build.gradle.kts
configuration closure (by axkb, #112):
configure<com.epages.restdocs.apispec.gradle.OpenApi3Extension> {
setServer("http://$apiHost:$apiPort")
title = "Your title"
description = "Your description"
version = "0.1.0"
format = "json"
tagDescriptionsPropertiesFile = "src/test/resources/tags.yaml"
}
The servers
and server
property can also contain variables. Is this case the` property can be specified like this:
This configuration follows the same semantics as the 'Servers Object' in the OpenAPI specification
servers = [ {
url = 'https://{host}/api'
variables = [
host: [
default: 'api-shop.beyondshop.cloud/api',
description: 'The hostname of your beyond shop',
enum: ['api-shop', 'oz']
]
]
} ]
The same structure applies to server
.
A single server can also be specified using a plain string:
server = 'http://some.api/api'
The restdocs-api-spec-gradle-plugin
takes the following configuration options for Postman collections - all are optional.
Name | Description | Default value |
---|---|---|
title | The title of the application. Used for the name attribute of the Information object of the collection |
API documentation |
version | The version of the api. Used for the version attribute in the Information object |
project version if specified - otherwise 1.0.0 |
baseUrl | The baseUrl of the application. e.g. https://myapi.example.com:8080/api |
http://localhost |
Example configuration closure:
postman {
title = 'Beyond REST API'
version = '1.0.1'
baseUrl = 'https://api-shop.beyondshop.cloud/api'
separatePublicApi = true
outputFileNamePrefix = 'my-postman-collection'
}
We can use redoc to generate an HTML API reference from our OpenAPI specification.
The redoc-cli can be used to bundle (and serve) this API reference:
# Install redoc-cli
npm install -g redoc-cli
# Bundle the documentation into a zero-dependency HTML-file
redoc-cli bundle build/api-spec/openapi.json
# Bundle and serve
redoc-cli serve build/api-spec/openapi.json
This project supersedes restdocs-raml.
So if you are coming from restdocs-raml
you might want to switch to restdocs-api-spec
.
The API of both projects is fairly similar and it is easy to migrate.
We plan to support RAML in the future. In the meantime you can use one of several ways to convert an OpenAPI specification to RAML. There are converters around that can help you to achieve this conversion.
- oas-raml-converter - an npm project that provides a CLI to convert between OpenAPI and RAML - it also provides an online converter
- api-matic - an online converter capable of converting between many api specifications
In the sample project you find a build configuration that uses the oas-raml-converter-docker docker image and the gradle-docker-plugin to leverage the oas-raml-converter
to convert the output of the openapi
task to RAML.
Using this approach your gradle build can still output a RAML specification.
See openapi2raml.gradle.
./gradlew restdocs-api-spec-sample:openapi
./gradlew -b samples/restdocs-api-spec-sample/openapi2raml.gradle openapi2raml
This section of the README is targeted at project maintainers.
The project is published with the help of TravisCI. It's version number is determined by the Git tags (see allegro/axion-release-plugin). The Java dependencies are published to Sonatype with the help of the gradle-nexus/publish-plugin and the Maven Publish Plugin. The Gradle plugin is published to the Gradle plugin portal with the help of the 'plugin-publish' plugin (see docs.gradle.org).
Given that the master
branch on the upstream repository is in the state from which you want to create a release, execute the following steps:
- Create release via the GitHub UI
Use the intended version number as "Tag version", e.g. "0.16.0". This will automatically trigger a Travis build which publishes the JAR files for this release to Sonatype. - Login to Sonatype and navigate to the staging repositories
- Close the staging repository
Select the generated staging repository and close it. Check that there are no errors afterwards (e.g. missing signatures or Javadoc JARs). - Release the repository
Select the generated staging repository and release it. Soon after, the release should be available in the "Public Repositories" of ePages. - Update documentation
Create a new commit which updates the version numbers in theREADME
file.