test: add test for debugger restart message issue

Running "restart" in the debugger confusingly prints an out-of-date
"Debugger listening on..." message before printing a second updated one.

Refs: #39272

Author: Trott

test/known_issues/test-debugger-restart-message.js

@@ -0,0 +1,41 @@
+'use strict';
+
+// Refs: https://github.com/nodejs/node/issues/39272
+
+const common = require('../common');
+
+common.skipIfInspectorDisabled();
+
+const fixtures = require('../common/fixtures');
+const startCLI = require('../common/debugger');
+
+const assert = require('assert');
+
+// Using `restart` should result in only one "Connect/For help" message.
+{
+  const script = fixtures.path('debugger', 'three-lines.js');
+  const cli = startCLI([script]);
+
+  function onFatal(error) {
+    cli.quit();
+    throw error;
+  }
+
+  const listeningRegExp = /Debugger listening on/g;
+
+  cli.waitForInitialBreak()
+    .then(() => cli.waitForPrompt())
+    .then(() => {
+      assert.strictEqual(cli.output.match(listeningRegExp).length, 1);
+    })
+    .then(() => cli.flushOutput())
+    .then(() => {
+      assert.strictEqual(cli.output.match(listeningRegExp), null);
+    })
+    .then(() => cli.stepCommand('restart'))
+    .then(() => {
+      assert.strictEqual(cli.output.match(listeningRegExp).length, 1);
+    })
+    .then(() => cli.quit())
+    .then(null, onFatal);
+}