Typing the Return Type of a Service Effect in TypeScript

export class AiModel extends Effect.Service<AiModel>()("AiModel", {
  effect: Effect.gen(function* () {
    const config = yield* AiConfig;
    const model: LanguageModel = createAzure({
      apiKey: config.apiKey,
      resourceName: config.resourceName,
    })("gpt-5-mini");
    return { model };
  }),
}) {
  static TestLayer = Layer.succeed(
    AiModel,
    AiModel.of({
      model: "test-model",
    }),
  );
}

export class AiModel extends Effect.Service<AiModel>()("AiModel", {
  effect: Effect.gen(function* () {
    const config = yield* AiConfig;
    const model: LanguageModel = createAzure({
      apiKey: config.apiKey,
      resourceName: config.resourceName,
    })("gpt-5-mini");
    return { model };
  }),
}) {
  static TestLayer = Layer.succeed(
    AiModel,
    AiModel.of({
      model: "test-model",
    }),
  );
}