build: check patches on update (#23103)

script/check-patch-diff.js

@@ -0,0 +1,18 @@
+const { spawnSync } = require('child_process');
+const path = require('path');
+const { inspect } = require('util');
+
+const srcPath = path.resolve(__dirname, '..', '..', '..');
+const patchExportFnPath = path.resolve(__dirname, 'export_all_patches.py');
+const configPath = path.resolve(__dirname, '..', 'patches', 'config.json');
+
+// Re-export all the patches to check if there were changes.
+const proc = spawnSync('python', [patchExportFnPath, configPath, '--dry-run'], {
+  cwd: srcPath
+});
+
+// Fail if patch exporting returned 1, e.g dry run failed.
+if (proc.status === 1) {
+  console.log(proc.stderr.toString('utf8'));
+  process.exit(1);
+}