Add initial unit tests

Author: eterna2

frontend/server/aws-helper-test.ts

@@ -0,0 +1,62 @@
+// Copyright 2019 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+import fetch from 'node-fetch';
+import { awsInstanceProfileCredentials } from './aws-helper';
+
+jest.mock('node-fetch');
+
+function sleep(ms) {
+  return new Promise(resolve => {
+    setTimeout(resolve, ms);
+  });
+}
+
+it('getIAMInstanceProfile', async () => {
+  let count = 0;
+  const expectedCredentials = [
+    {
+      Code: 'Success',
+      LastUpdated: '2019-12-17T10:55:38Z',
+      Type: 'AWS-HMAC',
+      AccessKeyId: 'AccessKeyId',
+      SecretAccessKey: 'SecretAccessKey',
+      Token: 'SessionToken',
+      Expiration: new Date(Date.now() + 1000).toISOString(), // expires 1 sec later
+    },
+    {
+      Code: 'Success',
+      LastUpdated: '2019-12-17T10:55:38Z',
+      Type: 'AWS-HMAC',
+      AccessKeyId: 'AccessKeyId2',
+      SecretAccessKey: 'SecretAccessKey2',
+      Token: 'SessionToken2',
+      Expiration: new Date(Date.now() + 10000).toISOString(), // expires 10 sec later
+    },
+  ];
+  const mockFetch = (url: string) => {
+    if (url === 'http://169.254.169.254/latest/meta-data/iam/security-credentials/') {
+      return Promise.resolve({ text: () => Promise.resolve('some_iam_role') });
+    }
+    return Promise.resolve({
+      json: () => Promise.resolve(expectedCredentials[count++]),
+    });
+  };
+  fetch.mockImplementation(mockFetch);
+  sleep;
+  expect(await awsInstanceProfileCredentials.getCredentials()).toBe(expectedCredentials[0]);
+  expect(await awsInstanceProfileCredentials.getCredentials()).toBe(expectedCredentials[0]);
+  await sleep(1500)
+  expect(await awsInstanceProfileCredentials.getCredentials()).toBe(expectedCredentials[1]);
+  expect(await awsInstanceProfileCredentials.getCredentials()).toBe(expectedCredentials[1]);
+});

frontend/server/aws-helper.ts

@@ -25,7 +25,7 @@ export interface IAWSMetadataCredentials {
 }
 
 /** url for aws metadata store. */
-const metadataUrl = 'http://169.254.169.254/latest/meta-data/';
+const metadataUrl = 'http://169.254.169.254/latest/meta-data';
 
 /**
  * Get the AWS IAM instance profile.