Change release script to only update version comment for changed files (#3033)

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>
(cherry picked from commit 1ffcb10b)

package.json

@@ -78,6 +78,7 @@
     "prettier": "^2.3.0",
     "prettier-plugin-solidity": "^1.0.0-beta.16",
     "rimraf": "^3.0.2",
+    "semver": "^7.3.5",
     "solhint": "^3.3.6",
     "solidity-ast": "^0.4.25",
     "solidity-coverage": "^0.7.11",

scripts/release/update-comment.js

 #!/usr/bin/env node
-
 const fs = require('fs');
-const glob = require('glob');
 const proc = require('child_process');
+const semver = require('semver');
+const run = (cmd, ...args) => proc.execFileSync(cmd, args, { encoding: 'utf8' }).trim();
 
-const gitStatus = proc.execFileSync('git', ['status', '--porcelain', '-uno', 'contracts/**/*.sol']);
-
+const gitStatus = run('git', 'status', '--porcelain', '-uno', 'contracts/**/*.sol');
 if (gitStatus.length > 0) {
   console.error('Contracts directory is not clean');
   process.exit(1);
@@ -13,15 +12,24 @@ if (gitStatus.length > 0) {
 
 const { version } = require('../../package.json');
 
-const files = glob.sync('contracts/!(mocks)/**/*.sol');
+// Get latest tag according to semver.
+const [ tag ] = run('git', 'tag')
+  .split(/\r?\n/)
+  .filter(v => semver.lt(semver.coerce(v), version)) // only consider older tags, ignore current prereleases
+  .sort(semver.rcompare);
+
+// Ordering tag → HEAD is important here.
+const files = run('git', 'diff', tag, 'HEAD', '--name-only', 'contracts/**/*.sol')
+  .split(/\r?\n/)
+  .filter(file => file && !file.match(/mock/i));
 
 for (const file of files) {
   const current = fs.readFileSync(file, 'utf8');
   const updated = current.replace(
-    /(\/\/ SPDX-License-Identifier:.*)$(\n\/\/ OpenZeppelin Contracts v.*$)?/m,
-    `$1\n// OpenZeppelin Contracts v${version} (${file.replace('contracts/', '')})`,
+    /(\/\/ SPDX-License-Identifier:.*)$(\n\/\/ OpenZeppelin Contracts .*$)?/m,
+    `$1\n// OpenZeppelin Contracts (last updated v${version}) (${file.replace('contracts/', '')})`,
   );
   fs.writeFileSync(file, updated);
 }
 
-proc.execFileSync('git', ['add', '--update', 'contracts']);
+run('git', 'add', '--update', 'contracts');