backstage/.changeset/wet-seas-deliver.md

@backstage/core-app-api, @backstage/test-utils

@backstage/core-app-api	@backstage/test-utils
patch	patch

The ApiRegistry from @backstage/core-app-api class has been deprecated and will be removed in a future release. To replace it, we have introduced two new helpers that are exported from @backstage/test-utils, namely TestApiProvider and TestApiRegistry.

These two new helpers are more tailored for writing tests and development setups, as they allow for partial implementations of each of the APIs.

When migrating existing code it is typically best to prefer usage of TestApiProvider when possible, so for example the following code:

render(
  <ApiProvider
    apis={ApiRegistry.from([
      [identityApiRef, mockIdentityApi as unknown as IdentityApi]
    ])}
  >
    {...}
  </ApiProvider>
)

Would be migrated to this:

render(
  <TestApiProvider apis={[[identityApiRef, mockIdentityApi]]}>
    {...}
  </TestApiProvider>
)

In cases where the ApiProvider is used in a more standalone way, for example to reuse a set of APIs across multiple tests, the TestApiRegistry can be used instead. Note that the TestApiRegistry only has a single static factory method, .from(), and it is slightly different from the existing .from() method on ApiRegistry in that it doesn't require the API pairs to be wrapped in an outer array.

Usage that looks like this:

const apis = ApiRegistry.with(
  identityApiRef,
  mockIdentityApi as unknown as IdentityApi,
).with(configApiRef, new ConfigReader({}));

OR like this:

const apis = ApiRegistry.from([
  [identityApiRef, mockIdentityApi as unknown as IdentityApi],
  [configApiRef, new ConfigReader({})],
]);

Would be migrated to this:

const apis = TestApiRegistry.from(
  [identityApiRef, mockIdentityApi],
  [configApiRef, new ConfigReader({})],
);

If your app is still using the ApiRegistry to construct the apis for createApp, we recommend that you move over to use the new method of supplying API factories instead, using createApiFactory.