Timeline: repair oldest/newest metrics if we fetch nothing

ts/test-node/license_comments_test.ts

@@ -0,0 +1,115 @@
+// Copyright 2020 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { assert } from 'chai';
+import * as path from 'path';
+import * as fs from 'fs';
+import { promisify } from 'util';
+import * as readline from 'readline';
+import * as childProcess from 'child_process';
+import pMap from 'p-map';
+
+const exec = promisify(childProcess.exec);
+
+const EXTENSIONS_TO_CHECK = new Set([
+  '.eslintignore',
+  '.gitattributes',
+  '.gitignore',
+  '.nvmrc',
+  '.prettierignore',
+  '.sh',
+  '.snyk',
+  '.yarnclean',
+  '.yml',
+  '.js',
+  '.scss',
+  '.ts',
+  '.tsx',
+  '.html',
+  '.md',
+  '.plist',
+]);
+const FILES_TO_IGNORE = new Set([
+  'ISSUE_TEMPLATE.md',
+  'Mp3LameEncoder.min.js',
+  'PULL_REQUEST_TEMPLATE.md',
+  'WebAudioRecorderMp3.js',
+]);
+
+const rootPath = path.join(__dirname, '..', '..');
+
+async function getGitFiles(): Promise<Array<string>> {
+  return (await exec('git ls-files', { cwd: rootPath, env: {} })).stdout
+    .split(/\n/g)
+    .map(line => line.trim())
+    .filter(Boolean)
+    .map(file => path.join(rootPath, file));
+}
+
+// This is not technically the real extension.
+function getExtension(file: string): string {
+  if (file.startsWith('.')) {
+    return getExtension(`x.${file}`);
+  }
+  return path.extname(file);
+}
+
+function readFirstTwoLines(file: string): Promise<Array<string>> {
+  return new Promise(resolve => {
+    const lines: Array<string> = [];
+
+    const lineReader = readline.createInterface({
+      input: fs.createReadStream(file),
+    });
+    lineReader.on('line', line => {
+      lines.push(line);
+      if (lines.length >= 2) {
+        lineReader.close();
+      }
+    });
+    lineReader.on('close', () => {
+      resolve(lines);
+    });
+  });
+}
+
+describe('license comments', () => {
+  it('includes a license comment at the top of every relevant file', async function test() {
+    // This usually executes quickly but can be slow in some cases, such as Windows CI.
+    this.timeout(10000);
+
+    const currentYear = new Date().getFullYear();
+
+    await pMap(
+      await getGitFiles(),
+      async (file: string) => {
+        if (
+          FILES_TO_IGNORE.has(path.basename(file)) ||
+          path.relative(rootPath, file).startsWith('components')
+        ) {
+          return;
+        }
+
+        const extension = getExtension(file);
+        if (!EXTENSIONS_TO_CHECK.has(extension)) {
+          return;
+        }
+
+        const [firstLine, secondLine] = await readFirstTwoLines(file);
+
+        assert.match(
+          firstLine,
+          RegExp(`Copyright (?:\\d{4}-)?${currentYear} Signal Messenger, LLC`),
+          `First line of ${file} is missing correct license header comment`
+        );
+        assert.include(
+          secondLine,
+          'SPDX-License-Identifier: AGPL-3.0-only',
+          `Second line of ${file} is missing correct license header comment`
+        );
+      },
+      // Without this, we may run into "too many open files" errors.
+      { concurrency: 100 }
+    );
+  });
+});