chore: implement identify (#304)

Initial implementation of identify, good enough for an alpha release.

---------

Co-authored-by: Yusinto Ngadiman <[email protected]>
Co-authored-by: Ryan Lamb <[email protected]>
Co-authored-by: LaunchDarklyReleaseBot <[email protected]>

Author: 3 people

packages/shared/sdk-client/src/LDClientImpl.test.ts

@@ -1,34 +1,35 @@
 import { LDContext } from '@launchdarkly/js-sdk-common';
-import { basicPlatform } from '@launchdarkly/private-js-mocks';
+import { basicPlatform, logger } from '@launchdarkly/private-js-mocks';
 
+import LDEmitter from './api/LDEmitter';
 import fetchFlags from './evaluation/fetchFlags';
 import * as mockResponseJson from './evaluation/mockResponse.json';
 import LDClientImpl from './LDClientImpl';
 
-jest.mock('./evaluation/fetchFlags', () => {
-  const actual = jest.requireActual('./evaluation/fetchFlags');
-  return {
-    __esModule: true,
-    ...actual,
-    default: jest.fn(),
-  };
-});
+jest.mock('./api/LDEmitter');
+jest.mock('./evaluation/fetchFlags');
 
 describe('sdk-client object', () => {
   const testSdkKey = 'test-sdk-key';
   const context: LDContext = { kind: 'org', key: 'Testy Pizza' };
   const mockFetchFlags = fetchFlags as jest.Mock;
 
   let ldc: LDClientImpl;
+  let mockEmitter: LDEmitter;
 
-  beforeEach(async () => {
+  beforeEach(() => {
     mockFetchFlags.mockResolvedValue(mockResponseJson);
 
-    ldc = new LDClientImpl(testSdkKey, context, basicPlatform, {});
-    await ldc.start();
+    ldc = new LDClientImpl(testSdkKey, context, basicPlatform, { logger });
+    [mockEmitter] = (LDEmitter as jest.Mock).mock.instances;
+  });
+
+  afterEach(() => {
+    jest.resetAllMocks();
   });
 
   test('instantiate with blank options', () => {
+    ldc = new LDClientImpl(testSdkKey, context, basicPlatform, {});
     expect(ldc.config).toMatchObject({
       allAttributesPrivate: false,
       baseUri: 'https://sdk.launchdarkly.com',
@@ -61,6 +62,7 @@ describe('sdk-client object', () => {
   });
 
   test('all flags', async () => {
+    await ldc.start();
     const all = ldc.allFlags();
 
     expect(all).toEqual({
@@ -76,8 +78,45 @@ describe('sdk-client object', () => {
   });
 
   test('variation', async () => {
+    await ldc.start();
     const devTestFlag = ldc.variation('dev-test-flag');
 
     expect(devTestFlag).toBe(true);
   });
+
+  test('identify success', async () => {
+    mockResponseJson['dev-test-flag'].value = false;
+    mockFetchFlags.mockResolvedValue(mockResponseJson);
+    const carContext: LDContext = { kind: 'car', key: 'mazda-cx7' };
+
+    await ldc.identify(carContext);
+    const c = ldc.getContext();
+    const all = ldc.allFlags();
+
+    expect(carContext).toEqual(c);
+    expect(all).toMatchObject({
+      'dev-test-flag': false,
+    });
+  });
+
+  test('identify error invalid context', async () => {
+    // @ts-ignore
+    const carContext: LDContext = { kind: 'car', key: undefined };
+
+    await expect(ldc.identify(carContext)).rejects.toThrowError(/no key/);
+    expect(logger.error).toBeCalledTimes(1);
+    expect(mockEmitter.emit).toHaveBeenNthCalledWith(1, 'error', expect.any(Error));
+    expect(ldc.getContext()).toEqual(context);
+  });
+
+  test('identify error fetch error', async () => {
+    // @ts-ignore
+    mockFetchFlags.mockRejectedValue(new Error('unknown test fetch error'));
+    const carContext: LDContext = { kind: 'car', key: 'mazda-3' };
+
+    await expect(ldc.identify(carContext)).rejects.toThrowError(/fetch error/);
+    expect(logger.error).toBeCalledTimes(1);
+    expect(mockEmitter.emit).toHaveBeenNthCalledWith(1, 'error', expect.any(Error));
+    expect(ldc.getContext()).toEqual(context);
+  });
 });

packages/shared/sdk-client/src/LDClientImpl.ts

@@ -45,19 +45,14 @@ export default class LDClientImpl implements LDClient {
    */
   constructor(
     public readonly sdkKey: string,
-    public readonly context: LDContext,
+    public context: LDContext,
     public readonly platform: Platform,
     options: LDOptions,
   ) {
     if (!sdkKey) {
       throw new Error('You must configure the client with a client-side SDK key');
     }
 
-    const checkedContext = Context.fromLDContext(context);
-    if (!checkedContext.valid) {
-      throw new Error('Context was unspecified or had no key');
-    }
-
     if (!platform.encoding) {
       throw new Error('Platform must implement Encoding because btoa is required.');
     }
@@ -78,12 +73,11 @@ export default class LDClientImpl implements LDClient {
 
   async start() {
     try {
-      this.flags = await fetchFlags(this.sdkKey, this.context, this.config, this.platform);
+      await this.identify(this.context);
       this.emitter.emit('ready');
     } catch (error: any) {
-      this.logger.error(error);
-      this.emitter.emit('error', error);
       this.emitter.emit('failed', error);
+      throw error;
     }
   }
 
@@ -113,13 +107,24 @@ export default class LDClientImpl implements LDClient {
     return clone(this.context);
   }
 
-  identify(
-    context: LDContext,
-    hash?: string,
-    onDone?: (err: Error | null, flags: LDFlagSet | null) => void,
-  ): Promise<LDFlagSet> {
-    // TODO:
-    return Promise.resolve({});
+  // TODO: implement secure mode
+  async identify(context: LDContext, hash?: string): Promise<void> {
+    const checkedContext = Context.fromLDContext(context);
+    if (!checkedContext.valid) {
+      const error = new Error('Context was unspecified or had no key');
+      this.logger.error(error);
+      this.emitter.emit('error', error);
+      throw error;
+    }
+
+    try {
+      this.flags = await fetchFlags(this.sdkKey, context, this.config, this.platform);
+      this.context = context;
+    } catch (error: any) {
+      this.logger.error(error);
+      this.emitter.emit('error', error);
+      throw error;
+    }
   }
 
   off(eventName: EventName, listener?: Function): void {

packages/shared/sdk-client/src/api/LDClient.ts

@@ -89,21 +89,10 @@ export interface LDClient {
    *   The context properties. Must contain at least the `key` property.
    * @param hash
    *   The signed context key if you are using [Secure Mode](https://docs.launchdarkly.com/sdk/features/secure-mode#configuring-secure-mode-in-the-javascript-client-side-sdk).
-   * @param onDone
-   *   A function which will be called as soon as the flag values for the new context are available,
-   *   with two parameters: an error value (if any), and an {@link LDFlagSet} containing the new values
-   *   (which can also be obtained by calling {@link variation}). If the callback is omitted, you will
-   *   receive a Promise instead.
    * @returns
-   *   If you provided a callback, then nothing. Otherwise, a Promise which resolve once the flag
-   *   values for the new context are available, providing an {@link LDFlagSet} containing the new values
-   *   (which can also be obtained by calling {@link variation}).
+   *   A Promise which resolve once the flag values for the new context are available.
    */
-  identify(
-    context: LDContext,
-    hash?: string,
-    onDone?: (err: Error | null, flags: LDFlagSet | null) => void,
-  ): Promise<LDFlagSet>;
+  identify(context: LDContext, hash?: string): Promise<void>;
 
   /**
    * Returns the client's current context.