test: add test for setupHistory callback error

Author: wcr-karan

test/parallel/test-repl-setup-history-error.js

@@ -0,0 +1,26 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const { spawnSync } = require('child_process');
+
+// This test verifies that setupHistory callback errors propagate.
+// On main branch (without your fix), this test MUST FAIL.
+// After your patch, it MUST PASS.
+
+const child = spawnSync(process.execPath, ['-e', `
+  const repl = require('repl');
+  const server = repl.start({ prompt: "" });
+  server.setupHistory('/tmp/history-test', (err) => {
+    throw new Error("INTENTIONAL_CALLBACK_THROW");
+  });
+`], {
+  encoding: 'utf8'
+});
+
+// The bug: before your fix, Node *does NOT* propagate the thrown error,
+// so stderr does NOT contain the message.
+// After your fix, stderr WILL contain INTENTIONAL_CALLBACK_THROW.
+
+assert.match(child.stderr, /INTENTIONAL_CALLBACK_THROW/, 
+  'setupHistory callback error did NOT propagate');
+