test: improve readline/emitKeypressEvents.js coverage

PR-URL: #42908
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com>

test/parallel/test-readline-emit-keypress-events.js

@@ -7,22 +7,66 @@ require('../common');
 const assert = require('assert');
 const readline = require('readline');
 const PassThrough = require('stream').PassThrough;
-const stream = new PassThrough();
-const sequence = [];
-const keys = [];
 
-readline.emitKeypressEvents(stream);
-
-stream.on('keypress', (s, k) => {
-  sequence.push(s);
-  keys.push(k);
-});
-
-stream.write('foo');
-
-assert.deepStrictEqual(sequence, ['f', 'o', 'o']);
-assert.deepStrictEqual(keys, [
+const expectedSequence = ['f', 'o', 'o'];
+const expectedKeys = [
   { sequence: 'f', name: 'f', ctrl: false, meta: false, shift: false },
   { sequence: 'o', name: 'o', ctrl: false, meta: false, shift: false },
   { sequence: 'o', name: 'o', ctrl: false, meta: false, shift: false },
-]);
+];
+
+{
+  const stream = new PassThrough();
+  const sequence = [];
+  const keys = [];
+
+  readline.emitKeypressEvents(stream);
+  stream.on('keypress', (s, k) => {
+    sequence.push(s);
+    keys.push(k);
+  });
+  stream.write('foo');
+
+  assert.deepStrictEqual(sequence, expectedSequence);
+  assert.deepStrictEqual(keys, expectedKeys);
+}
+
+{
+  const stream = new PassThrough();
+  const sequence = [];
+  const keys = [];
+
+  stream.on('keypress', (s, k) => {
+    sequence.push(s);
+    keys.push(k);
+  });
+  readline.emitKeypressEvents(stream);
+  stream.write('foo');
+
+  assert.deepStrictEqual(sequence, expectedSequence);
+  assert.deepStrictEqual(keys, expectedKeys);
+}
+
+{
+  const stream = new PassThrough();
+  const sequence = [];
+  const keys = [];
+  const keypressListener = (s, k) => {
+    sequence.push(s);
+    keys.push(k);
+  };
+
+  stream.on('keypress', keypressListener);
+  readline.emitKeypressEvents(stream);
+  stream.removeListener('keypress', keypressListener);
+  stream.write('foo');
+
+  assert.deepStrictEqual(sequence, []);
+  assert.deepStrictEqual(keys, []);
+
+  stream.on('keypress', keypressListener);
+  stream.write('foo');
+
+  assert.deepStrictEqual(sequence, expectedSequence);
+  assert.deepStrictEqual(keys, expectedKeys);
+}