tools: implement update-authors in JS

Replace the previous Perl script with a Node.js variant
that explicitly supports `Author:` and, in particular,
GitHub’s standard `Co-authored-by:` metadata tags.

PR-URL: #22771
Reviewed-By: Michaël Zasso <[email protected]>
Reviewed-By: Daniel Bevenius <[email protected]>
Reviewed-By: Tobias Nießen <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Matheus Marchini <[email protected]>
Reviewed-By: Richard Lau <[email protected]>
Reviewed-By: Ruben Bridgewater <[email protected]>
Reviewed-By: Matteo Collina <[email protected]>
Reviewed-By: James M Snell <[email protected]>

Author: addaleax

tools/update-authors.js

@@ -0,0 +1,50 @@
+#!/usr/bin/env node
+// Usage: tools/update-author.js [--dry]
+// Passing --dry will redirect output to stdout rather than write to 'AUTHORS'.
+'use strict';
+const { spawn } = require('child_process');
+const fs = require('fs');
+const readline = require('readline');
+
+const log = spawn(
+  'git',
+  // Inspect author name/email and body.
+  ['log', '--reverse', '--format=Author: %aN <%aE>\n%b'], {
+    stdio: ['inherit', 'pipe', 'inherit']
+  });
+const rl = readline.createInterface({ input: log.stdout });
+
+let output;
+if (process.argv.includes('--dry'))
+  output = process.stdout;
+else
+  output = fs.createWriteStream('AUTHORS');
+
+output.write('# Authors ordered by first contribution.\n\n');
+
+const seen = new Set();
+
+// Support regular git author metadata, as well as `Author:` and
+// `Co-authored-by:` in the message body. Both have been used in the past
+// to indicate multiple authors per commit, with the latter standardized
+// by GitHub now.
+const authorRe =
+  /(^Author:|^Co-authored-by:)\s+(?<author>[^<]+)\s+(?<email><[^>]+>)/i;
+rl.on('line', (line) => {
+  const match = line.match(authorRe);
+  if (!match) return;
+
+  const { author, email } = match.groups;
+  if (seen.has(email) ||
+      /@chromium\.org/.test(email) ||
+      email === '<[email protected]>') {
+    return;
+  }
+
+  seen.add(email);
+  output.write(`${author} ${email}\n`);
+});
+
+rl.on('close', () => {
+  output.end('\n# Generated by tools/update-authors.js\n');
+});