Add changelog script

scripts/changelog.ts

@@ -0,0 +1,30 @@
+import fs from 'fs';
+import { join } from 'path';
+
+const version = process.argv[2].replace('v', '');
+
+function parseChangelog(changelog: string): Record<string, string> {
+  const result: Record<string, string> = {};
+
+  let currentVersion: string;
+  changelog.split('\n').forEach(line => {
+    const match = line.match(/^## \[([\d.]+)\](?: - [\d-]+)?$/);
+    if (match) {
+      currentVersion = match[1];
+    } else if (currentVersion) {
+      result[currentVersion] = (result[currentVersion] || '') + line + '\n';
+    }
+  });
+
+  return result;
+}
+
+const changelog = fs.readFileSync(join(__dirname, '..', 'CHANGELOG.md'), 'utf8');
+const parsed = parseChangelog(changelog);
+
+// Log to stdout so we can redirect it in CI.
+// eslint-disable-next-line no-console
+console.log((parsed[version] || '').trim());
+
+
+