build: fix mysterious await failure (#2117)

package.json

@@ -58,6 +58,7 @@
     "@types/node": "^12.0.1",
     "@types/nunjucks": "^3.1.1",
     "@types/prettier": "^2.0.0",
+    "@types/proxyquire": "^1.3.28",
     "@types/qs": "^6.5.3",
     "@types/rimraf": "^3.0.0",
     "@types/sinon": "^9.0.0",
@@ -80,6 +81,7 @@
     "open": "^7.0.0",
     "p-queue": "^6.0.0",
     "prettier": "^2.0.5",
+    "proxyquire": "^2.1.3",
     "rimraf": "^3.0.0",
     "server-destroy": "^1.0.1",
     "sinon": "^9.0.2",

src/generator/download.ts

@@ -60,7 +60,11 @@ export async function downloadDiscoveryDocs(options: DownloadOptions) {
   gfs.writeFile(indexPath, res.data);
   const queue = new Q({concurrency: 25});
   console.log(`Downloading ${apis.length} APIs...`);
-  const changes = await queue.addAll(
+  // If you await the result of `queue.addAll`, the process mysteriously
+  // exits after downloading all the files. I have no earthly idea why.
+  // Software is terrible.
+  //const changes = await queue.addAll(
+  queue.addAll(
     apis.map(api => {
       return async () => {
         console.log(`Downloading ${api.id}...`);
@@ -90,7 +94,7 @@ export async function downloadDiscoveryDocs(options: DownloadOptions) {
     })
   );
   await queue.onIdle();
-  return changes;
+  //return changes;
 }
 
 const ignoreLines = /^\s+"(?:etag|revision)": ".+"/;

test/test.generator.ts

@@ -0,0 +1,56 @@
+// Copyright 2020 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 * as assert from 'assert';
+import * as sinon from 'sinon';
+import * as proxyquire from 'proxyquire';
+import {describe, it, afterEach} from 'mocha';
+import * as nock from 'nock';
+import * as gen from '../src/generator/generator';
+
+describe(__filename, () => {
+  nock.disableNetConnect();
+  const sandbox = sinon.createSandbox();
+
+  afterEach(() => sandbox.restore());
+
+  it('should read from cache if flag is passed', async () => {
+    // This test relies on the disabled network being enabled
+    const generator = new gen.Generator();
+    const genStub = sandbox.stub(generator, 'generateAPI').resolves();
+    const idxStub = sandbox.stub(generator, 'generateIndex').resolves();
+    await generator.generateAllAPIs('', true);
+    assert.ok(genStub.called);
+    assert.ok(idxStub.calledOnce);
+  });
+
+  it('should read from disco if flag is passed', async () => {
+    let downloadCalled = false;
+    const {Generator} = proxyquire('../src/generator/generator', {
+      './download': {
+        downloadDiscoveryDocs: async () => {
+          downloadCalled = true;
+        },
+      },
+    });
+    const generator = new Generator();
+    const genStub = sandbox.stub(generator, 'generateAPI').resolves();
+    const idxStub = sandbox.stub(generator, 'generateIndex').resolves();
+    const discoUrl = 'https://www.googleapis.com/discovery/v1/apis/';
+    await generator.generateAllAPIs(discoUrl, false);
+    assert.ok(genStub.called);
+    assert.ok(idxStub.calledOnce);
+    assert.ok(downloadCalled);
+  });
+});