test: add regression test for 13557

Fixes: #13557
PR-URL: #13560
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

test/parallel/test-readline-reopen.js

@@ -0,0 +1,44 @@
+'use strict';
+
+// Regression test for https://github.com/nodejs/node/issues/13557
+// Tests that multiple subsequent readline instances can re-use an input stream.
+
+const common = require('../common');
+const assert = require('assert');
+const readline = require('readline');
+const { PassThrough } = require('stream');
+
+const input = new PassThrough();
+const output = new PassThrough();
+
+const rl1 = readline.createInterface({
+ input,
+ output,
+ terminal: true
+});
+
+rl1.on('line', common.mustCall(rl1OnLine));
+
+// Write a line plus the first byte of a UTF-8 multibyte character to make sure
+// that it doesn’t get lost when closing the readline instance.
+input.write(Buffer.concat([
+ Buffer.from('foo\n'),
+ Buffer.from([ 0xe2 ]) // Exactly one third of a ☃ snowman.
+]));
+
+function rl1OnLine(line) {
+ assert.strictEqual(line, 'foo');
+ rl1.close();
+ const rl2 = readline.createInterface({
+ input,
+ output,
+ terminal: true
+ });
+
+ rl2.on('line', common.mustCall((line) => {
+ assert.strictEqual(line, '☃bar');
+ rl2.close();
+ }));
+ input.write(Buffer.from([0x98, 0x83])); // The rest of the ☃ snowman.
+ input.write('bar\n');
+}