test: add repl preview timeout test

test/parallel/test-repl-preview-timeout.js

@@ -0,0 +1,27 @@
+'use strict';
+
+const common = require('../common');
+const ArrayStream = require('../common/arraystream');
+const assert = require('assert');
+const repl = require('repl');
+
+common.skipIfInspectorDisabled();
+
+const inputStream = new ArrayStream();
+const outputStream = new ArrayStream();
+repl.start({
+  input: inputStream,
+  output: outputStream,
+  useGlobal: false,
+  terminal: true,
+  useColors: true
+});
+
+let output = '';
+outputStream.write = (chunk) => output += chunk;
+
+// Input without '\n' triggering actual run.
+const input = 'while (true) {}';
+inputStream.emit('data', input);
+// No preview available when timed out.
+assert.strictEqual(output, input);