Allow for copyrights to be assigned to Google LLC (#2665)

* Allow for copyrights assigned to Google LLC

Current guidance at go/copyright calls for copyright to be assigned to
Google LLC, like so:

  Copyright 2020 Google LLC

This change makes this the default without changing existing files.

* Add missing license header to license.js

* Remove unused chalk import

* Do license validation in a single pass

* Rewrite old-form copyrights

* Compute changed files once.

* [AUTOMATED]: License Headers

Author: wilhuff

tools/gitHooks/license.js

@@ -1,17 +1,30 @@
-const { promisify } = require('util');
+/**
+ * @license
+ * Copyright 2017 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.
+ */
+
 const { resolve } = require('path');
 const simpleGit = require('simple-git/promise');
-const chalk = require('chalk');
-const globRaw = require('glob');
 const fs = require('mz/fs');
 const ora = require('ora');
 
-const glob = promisify(globRaw);
 const root = resolve(__dirname, '../..');
 const git = simpleGit(root);
 const licenseHeader = `/**
  * @license
- * Copyright 2020 Google Inc.
+ * 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.
@@ -28,49 +41,72 @@ const licenseHeader = `/**
 
 `;
 
-async function doLicenseCommit() {
-  const licenseSpinner = ora(' Validating License Headers').start();
+const copyrightPattern = /Copyright \d{4} Google (Inc\.|LLC)/;
+const oldCopyrightPattern = /(\s*\*\s*Copyright \d{4}) Google Inc\./;
 
-  const paths = await glob('**/*.+(ts|js)', {
-    ignore: ['**/node_modules/**', '**/dist/**']
+async function readFiles(paths) {
+  const fileContents = await Promise.all(paths.map(path => fs.readFile(path)));
+  return fileContents.map((buffer, idx) => ({
+    contents: String(buffer),
+    path: paths[idx]
+  }));
+}
+
+function addLicenceTag(contents) {
+  const lines = contents.split('\n');
+  let newLines = [];
+  for (const line of lines) {
+    if (line.match(copyrightPattern)) {
+      const indent = line.split('*')[0]; // Get whitespace to match
+      newLines.push(indent + '* @license');
+    }
+    newLines.push(line);
+  }
+  return newLines.join('\n');
+}
+
+function rewriteCopyrightLine(contents) {
+  const lines = contents.split('\n');
+  let newLines = lines.map(line => {
+    return line.replace(oldCopyrightPattern, (_, leader) => {
+      return leader + ' Google LLC';
+    });
   });
+  return newLines.join('\n');
+}
 
-  // Files with no license block at all.
-  const fileContents = await Promise.all(paths.map(path => fs.readFile(path)));
-  const filesMissingLicensePaths = fileContents
-    .map((buffer, idx) => ({ buffer, path: paths[idx] }))
-    .filter(
-      ({ buffer }) =>
-        String(buffer).match(/Copyright \d{4} Google Inc\./) == null
-    );
+async function doLicenseCommit(changedFiles) {
+  const licenseSpinner = ora(' Validating License Headers').start();
 
-  await Promise.all(
-    filesMissingLicensePaths.map(({ buffer, path }) => {
-      const contents = Buffer.concat([new Buffer(licenseHeader), buffer]);
-      return fs.writeFile(path, contents, 'utf8');
-    })
-  );
+  const paths = changedFiles.filter(line => line.match(/(js|ts)$/));
+  if (paths.length === 0) return;
 
-  // Files with no @license tag.
-  const appendedFileContents = await Promise.all(
-    paths.map(path => fs.readFile(path))
-  );
-  const filesMissingTagPaths = appendedFileContents
-    .map((buffer, idx) => ({ buffer, path: paths[idx] }))
-    .filter(({ buffer }) => String(buffer).match(/@license/) == null);
+  const files = await readFiles(paths);
 
   await Promise.all(
-    filesMissingTagPaths.map(({ buffer, path }) => {
-      const lines = String(buffer).split('\n');
-      let newLines = [];
-      for (const line of lines) {
-        if (line.match(/Copyright \d{4} Google Inc\./)) {
-          const indent = line.split('*')[0]; // Get whitespace to match
-          newLines.push(indent + '* @license');
-        }
-        newLines.push(line);
+    files.map(({ contents, path }) => {
+      let result = contents;
+
+      // Files with no license block at all.
+      if (result.match(copyrightPattern) == null) {
+        result = licenseHeader + result;
+      }
+
+      // Files with no @license tag.
+      if (result.match(/@license/) == null) {
+        result = addLicenceTag(result);
+      }
+
+      // Files with the old form of copyright notice.
+      if (result.match(oldCopyrightPattern) != null) {
+        result = rewriteCopyrightLine(result);
+      }
+
+      if (contents !== result) {
+        return fs.writeFile(path, result, 'utf8');
+      } else {
+        return Promise.resolve();
       }
-      return fs.writeFile(path, newLines.join('\n'), 'utf8');
     })
   );
 

tools/gitHooks/prepush.js

@@ -1,6 +1,6 @@
 /**
  * @license
- * Copyright 2017 Google Inc.
+ * Copyright 2017 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -44,11 +44,18 @@ $ git stash pop
       return process.exit(1);
     }
 
+    const diff = await git.diff([
+      '--name-only',
+      '--diff-filter=d',
+      'origin/master...HEAD'
+    ]);
+    const changedFiles = diff.split('\n');
+
     // Style the code
-    await doPrettierCommit();
+    await doPrettierCommit(changedFiles);
 
     // Validate License headers exist
-    await doLicenseCommit();
+    await doLicenseCommit(changedFiles);
 
     console.log(chalk`
 Pre-Push Validation Succeeded

tools/gitHooks/prettier.js

@@ -1,6 +1,6 @@
 /**
  * @license
- * Copyright 2017 Google Inc.
+ * Copyright 2017 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -56,21 +56,16 @@ function checkVersion() {
   });
 }
 
-async function doPrettierCommit() {
+async function doPrettierCommit(changedFiles) {
   try {
     await checkVersion();
   } catch (e) {
     console.error(e);
     return process.exit(1);
   }
-  const diff = await git.diff([
-    '--name-only',
-    'origin/master...HEAD',
-    '--diff-filter',
-    'd'
-  ]);
+
   // Only run on .js or .ts files.
-  const targetFiles = diff.split('\n').filter(line => line.match(/(js|ts)$/));
+  const targetFiles = changedFiles.filter(line => line.match(/(js|ts)$/));
   if (targetFiles.length === 0) return;
 
   const stylingSpinner = ora(