1 files changed, 67 insertions, 0 deletions
diff --git a/tests/node_compat/test/parallel/test-stream-readable-setEncoding-existing-buffers.js b/tests/node_compat/test/parallel/test-stream-readable-setEncoding-existing-buffers.js
new file mode 100644
index 000000000..c99a39819
--- /dev/null
+++ b/tests/node_compat/test/parallel/test-stream-readable-setEncoding-existing-buffers.js
@@ -0,0 +1,67 @@
+// deno-fmt-ignore-file
+// deno-lint-ignore-file
+
+// Copyright Joyent and Node contributors. All rights reserved. MIT license.
+// Taken from Node 18.12.1
+// This file is automatically generated by `tools/node_compat/setup.ts`. Do not modify this file manually.
+
+'use strict';
+require('../common');
+const { Readable } = require('stream');
+const assert = require('assert');
+
+{
+  // Call .setEncoding() while there are bytes already in the buffer.
+  const r = new Readable({ read() {} });
+
+  r.push(Buffer.from('a'));
+  r.push(Buffer.from('b'));
+
+  r.setEncoding('utf8');
+  const chunks = [];
+  r.on('data', (chunk) => chunks.push(chunk));
+
+  process.nextTick(() => {
+    assert.deepStrictEqual(chunks, ['ab']);
+  });
+}
+
+{
+  // Call .setEncoding() while the buffer contains a complete,
+  // but chunked character.
+  const r = new Readable({ read() {} });
+
+  r.push(Buffer.from([0xf0]));
+  r.push(Buffer.from([0x9f]));
+  r.push(Buffer.from([0x8e]));
+  r.push(Buffer.from([0x89]));
+
+  r.setEncoding('utf8');
+  const chunks = [];
+  r.on('data', (chunk) => chunks.push(chunk));
+
+  process.nextTick(() => {
+    assert.deepStrictEqual(chunks, ['🎉']);
+  });
+}
+
+{
+  // Call .setEncoding() while the buffer contains an incomplete character,
+  // and finish the character later.
+  const r = new Readable({ read() {} });
+
+  r.push(Buffer.from([0xf0]));
+  r.push(Buffer.from([0x9f]));
+
+  r.setEncoding('utf8');
+
+  r.push(Buffer.from([0x8e]));
+  r.push(Buffer.from([0x89]));
+
+  const chunks = [];
+  r.on('data', (chunk) => chunks.push(chunk));
+
+  process.nextTick(() => {
+    assert.deepStrictEqual(chunks, ['🎉']);
+  });
+}