Writing Tests For Actions

Once you created a new action, your own custom one, or you would like to contribute new actions, you have to cover it with Unit tests to be sure that your actions do what they suppose to do.

Make sure that you cover the most of scenario's, which could happen with the action. One of indispensable part of the test is to supply the context to a handler of action for the execution. We encourage you to use a utility method for that, so your tests are immune to structural changes of context. What is inevitably going to happen during the time.

Example how to use it:

import { createMockActionContext } from '@backstage/plugin-scaffolder-node-test-utils';

const mockContext = createMockActionContext({
  input: { repoUrl: 'dev.azure.com?repo=repo&owner=owner&organization=org' },
});

await action.handler(mockContext);

expect(mockContext.output).toHaveBeenCalledWith(
  'remoteUrl',
  'https://dev.azure.com/organization/project/_git/repo',
);

One thing to be aware about: if you would like to call createMockActionContext inside it, you have to provide a workspacePath. By default, createMockActionContext uses import { createMockDirectory } from '@backstage/backend-test-utils'; to create it for you. This implementation contains a hook inside which creates this limitation. So in this case you can do then:

describe('github:autolinks:create', async () => {
  const workspacePath = createMockDirectory().resolve('workspace');
  // ...

  it('should call the githubApis for creating alphanumeric autolink reference', async () => {
    // ...
    await action.handler(
      createMockActionContext({
        input: {
          repoUrl: 'github.com?repo=repo&owner=owner',
          keyPrefix: 'TICKET-',
          urlTemplate: 'https://example.com/TICKET?query=<num>',
        },
        workspacePath,
      }),
    );
    //...
  });
});