test(api): add tests for API functions in api folder

test/api/spotifyAuthApi.test.js

@@ -0,0 +1,73 @@
+import { expect } from 'chai';
+import sinon from 'sinon';
+import esmock from 'esmock';
+
+describe('getSpotifyAccessToken', () => {
+  let axiosRetryStub;
+  let handleErrorStub;
+  let getSpotifyAccessToken;
+
+  beforeEach(async () => {
+    axiosRetryStub = sinon.stub();
+    handleErrorStub = sinon.stub();
+
+    // Mocking the spotifyAuthApi and its dependencies
+    const module = await esmock('../../src/api/spotifyAuthApi.js', {
+      '../../src/utils/retryAxios.js': axiosRetryStub,
+      '../../src/errors/generalApiErrorHandler.js': {
+        default: handleErrorStub,
+      },
+      'querystring': {
+        stringify: sinon.stub().returns('grant_type=client_credentials'),
+      },
+    });
+
+    getSpotifyAccessToken = module.default;
+  });
+
+  afterEach(() => {
+    sinon.restore(); // Restore the original state of sinon stubs
+    esmock.purge();  // Clean up any esmocked modules
+  });
+
+  it('should retrieve the Spotify access token', async () => {
+    process.env.client_id = 'mockClientId';
+    process.env.client_secret = 'mockClientSecret';
+
+    const token = 'mocked_access_token';
+    const response = { status: 200, data: { access_token: token } };
+    axiosRetryStub.resolves(response);
+
+    const result = await getSpotifyAccessToken();
+
+    expect(result).to.equal(token);
+    expect(axiosRetryStub.callCount).to.equal(1);
+    expect(axiosRetryStub.firstCall.args[0]).to.include({
+      url: 'https://accounts.spotify.com/api/token',
+    });
+    expect(axiosRetryStub.firstCall.args[0].headers.Authorization).to.include('Basic');
+  });
+
+  it('should throw an error if the request fails after retries', async () => {
+    process.env.client_id = 'mockClientId';
+    process.env.client_secret = 'mockClientSecret';
+
+    const errorMessage = 'Handled error message';
+    const error = new Error('Request failed');
+    axiosRetryStub.rejects(error);
+    handleErrorStub.returns(errorMessage);
+
+    try {
+      await getSpotifyAccessToken();
+      // We should not reach here
+      expect.fail('Expected getSpotifyAccessToken to throw');
+    } catch (err) {
+      expect(err.message).to.equal(errorMessage);
+      expect(handleErrorStub.callCount).to.equal(1);
+      expect(handleErrorStub.firstCall.args[0]).to.equal(error);
+    }
+
+    expect(axiosRetryStub.callCount).to.equal(1); // Only one stub call since retry logic is inside `retryAxios.js`
+  });
+});
+