build: resolve update-api workflow failure (googleapis#3766)

* fix update-api workflow failing

* readability

* add discovery docs filenames validation

Author: GautamSharda

src/generator/download.ts

@@ -113,6 +113,40 @@ export async function downloadDiscoveryDocs(
   return changes;
 }
 
+/**
+ * Checks that a discovery doc file name is in the expected format of
+ * [NAME(alphanumeric)]-[VERSION(alphanumeric, _, .)].json.
+ * Throws an error if the file name is not in the expected format.
+ * @param fileName The file name to validate
+ */
+export function validateDiscoveryDocFileName(fileName: string) {
+  const regex = /^[a-zA-Z0-9]+-[a-zA-Z0-9_.]+\.json$/;
+  if (!regex.test(fileName)) {
+    throw new Error(
+      `Discovery doc file name '${fileName}' is not in the expected format of '[NAME(alphanumeric)]-[VERSION(alphanumeric, _, .)].json'.`,
+    );
+  }
+}
+
+export interface ApiData {
+  name: string;
+  version: string;
+}
+
+/**
+ * Parses a discovery doc file name and returns the API name and version.
+ * @param fileName The file name to parse.
+ * @returns The API data (name and version).
+ */
+export function getApiData(fileName: string): ApiData {
+  validateDiscoveryDocFileName(fileName);
+  const firstHyphenIndex = fileName.indexOf('-');
+  const lastDotIndex = fileName.lastIndexOf('.');
+  const name = fileName.substring(0, firstHyphenIndex);
+  const version = fileName.substring(firstHyphenIndex + 1, lastDotIndex);
+  return {name, version};
+}
+
 // These are libraries we should no longer support because
 // they are not present in the index.json
 // example: b/148605368
@@ -123,22 +157,21 @@ function cleanupLibrariesNotInIndexJSON(
   const srcPath = path.join(__dirname, '../../../src', 'apis');
   const discoveryDirectory = fs.readdirSync(options.downloadPath);
   const apisReplaced = apis.map(
-    x => x.id.toString().replace(':', '-') + '.json',
+    api => api.id.toString().replace(':', '-') + '.json',
   );
   // So that we don't delete index.json
   apisReplaced.push('index.json');
   const discoveryDocsToDelete = discoveryDirectory.filter(
-    x => !apisReplaced.includes(x),
+    fileName => !apisReplaced.includes(fileName),
   );
-  const clientFilesToDelete = discoveryDocsToDelete.map(x => {
-    const apiName = x.split('-')[0];
-    const versionName = apiName[1].split('.')[0];
-    return path.join(srcPath, apiName, `${versionName}.ts`);
+  const clientFilesToDelete = discoveryDocsToDelete.map(docFileName => {
+    const api = getApiData(docFileName);
+    return path.join(srcPath, api.name, `${api.version}.ts`);
   });
-  discoveryDocsToDelete.forEach(x =>
-    fs.unlinkSync(path.join(options.downloadPath, x)),
+  discoveryDocsToDelete.forEach(docFileName =>
+    fs.unlinkSync(path.join(options.downloadPath, docFileName)),
   );
-  clientFilesToDelete.forEach(x => fs.unlinkSync(x));
+  clientFilesToDelete.forEach(clientFile => fs.unlinkSync(clientFile));
 }
 
 const ignoreLines = /^\s+"(?:etag|revision)": ".+"/;

test/test.download.ts

@@ -153,6 +153,35 @@ describe(__filename, () => {
     scopes.forEach(s => s.done());
   });
 
+  it('should clean up old files', async () => {
+    const readdirSync = sandbox.stub(fs, 'readdirSync');
+    const unlinkSync = sandbox.stub(fs, 'unlinkSync');
+    const downloadPath = 'build/test/temp';
+    readdirSync.returns(['a-v1.json', 'blogger-v2.json'] as any);
+    const scopes = [
+      nock(
+        'https://raw.githubusercontent.com/googleapis/discovery-artifact-manager/master/discoveries',
+      )
+        .get('/index.json')
+        .reply(200, JSON.stringify(fs.readFileSync(fakeIndexPath, 'utf8')), {
+          'Content-Type': 'application/json',
+        }),
+      nock(
+        'https://raw.githubusercontent.com/googleapis/discovery-artifact-manager/master/discoveries',
+      )
+        .get('/fake.v1.json')
+        .reply(
+          200,
+          '{"id": "fake:v1","discoveryRestUrl": "http://localhost:3030/path","name": "fake","version": "v1"}',
+        ),
+    ];
+    await dn.downloadDiscoveryDocs({discoveryUrl, downloadPath});
+    assert(unlinkSync.calledWith(path.join(downloadPath, 'blogger-v2.json')));
+    const expected = path.join(__dirname, '../../src/apis/blogger/v2.ts');
+    assert(unlinkSync.calledWith(expected));
+    scopes.forEach(s => s.done());
+  });
+
   it('should be invokable from the CLI', async () => {
     const port = 3030;
     const server = http
@@ -235,4 +264,26 @@ describe(__filename, () => {
     const result = dn.getDiffs(oldDoc, newDoc);
     assert.deepStrictEqual(result, expected);
   });
+
+  it('should validate discovery doc file names', () => {
+    assert.doesNotThrow(() =>
+      dn.validateDiscoveryDocFileName('apiname-v1.json'),
+    );
+    assert.doesNotThrow(() =>
+      dn.validateDiscoveryDocFileName('apiname-v1.1.json'),
+    );
+    assert.doesNotThrow(() =>
+      dn.validateDiscoveryDocFileName('apiname-v1_beta.json'),
+    );
+    assert.throws(() =>
+      dn.validateDiscoveryDocFileName('apiname-v1-extra.json'),
+    );
+    assert.throws(() => dn.validateDiscoveryDocFileName('api_name-v1.json'));
+    assert.throws(() => dn.validateDiscoveryDocFileName('apiname-v1.js'));
+  });
+
+  it('should parse discovery doc file names', () => {
+    const result = dn.getApiData('apiname-v1.2.json');
+    assert.deepStrictEqual(result, {name: 'apiname', version: 'v1.2'});
+  });
 });