Generating Stubs at Runtime

As a consumer, you might not want to wait for the producer to finish its implementation and then publish their stubs. A solution to this problem can be generation of stubs at runtime.

As a producer, when a contract is defined, you are required to make the generated tests pass in order for the stubs to be published. There are cases where you would like to unblock the consumers so that they can fetch the stubs before your tests actually pass. In this case, you should set such contracts as in-progress. You can read more about this under the Contracts in Progress section. That way, your tests are not generated, but the stubs are generated.

As a consumer, you can toggle a switch to generate stubs at runtime. Stub Runner ignores all the existing stub mappings and generates new ones for all the contract definitions. Another option is to pass the stubrunner.generate-stubs system property. The following example shows such a setup:

Annotation

@AutoConfigureStubRunner(
stubsMode = StubRunnerProperties.StubsMode.REMOTE,
		repositoryRoot = "stubs://file://location/to/the/contracts",
		ids = "com.example:some-producer",
		generateStubs = true)

JUnit 4 Rule

@Rule
	public StubRunnerRule rule = new StubRunnerRule()
			.downloadStub("com.example:some-producer")
			.repoRoot("stubs://file://location/to/the/contracts")
			.stubsMode(StubRunnerProperties.StubsMode.REMOTE)
			.withGenerateStubs(true);

JUnit 5 Extension

@RegisterExtension
	public StubRunnerExtension stubRunnerExtension = new StubRunnerExtension()
			.downloadStub("com.example:some-producer")
			.repoRoot("stubs://file://location/to/the/contracts")
			.stubsMode(StubRunnerProperties.StubsMode.REMOTE)
			.withGenerateStubs(true);