3 files changed, 101 insertions, 0 deletions
diff --git a/test/bun.js/process-stdio.test.ts b/test/bun.js/process-stdio.test.ts
new file mode 100644
index 000000000..886bf9dac
--- /dev/null
+++ b/test/bun.js/process-stdio.test.ts
@@ -0,0 +1,69 @@
+import { spawnSync } from "bun";
+import { describe, expect, it, test } from "bun:test";
+import { bunExe } from "bunExe";
+import { isatty } from "tty";
+
+test("process.stdout", () => {
+  expect(process.stdout).toBeDefined();
+  expect(process.stdout.isTTY).toBe(isatty(1));
+});
+
+test("process.stderr", () => {
+  expect(process.stderr).toBeDefined();
+  expect(process.stderr.isTTY).toBe(isatty(2));
+});
+
+test("process.stdout - write", () => {
+  const { stdout } = spawnSync({
+    cmd: [bunExe(), import.meta.dir + "/stdio-test-instance.js"],
+    stdout: "pipe",
+    stdin: null,
+    stderr: null,
+    env: {
+      ...process.env,
+      BUN_DEBUG_QUIET_LOGS: "1",
+    },
+  });
+
+  expect(stdout?.toString()).toBe(
+    `hello worldhello again|😋 Get Emoji — All Emojis to ✂️ Copy and 📋 Paste 👌`,
+  );
+});
+
+test("process.stdout - write a lot (string)", () => {
+  const { stdout } = spawnSync({
+    cmd: [bunExe(), import.meta.dir + "/stdio-test-instance-a-lot.js"],
+    stdout: "pipe",
+    stdin: null,
+    stderr: null,
+    env: {
+      ...process.env,
+      BUN_DEBUG_QUIET_LOGS: "1",
+      TEST_STDIO_STRING: "1",
+    },
+  });
+
+  expect(stdout?.toString()).toBe(
+    `hello worldhello again|😋 Get Emoji — All Emojis to ✂️ Copy and 📋 Paste 👌`.repeat(
+      9999,
+    ),
+  );
+});
+
+test("process.stdout - write a lot (bytes)", () => {
+  const { stdout } = spawnSync({
+    cmd: [bunExe(), import.meta.dir + "/stdio-test-instance-a-lot.js"],
+    stdout: "pipe",
+    stdin: null,
+    stderr: null,
+    env: {
+      ...process.env,
+      BUN_DEBUG_QUIET_LOGS: "1",
+    },
+  });
+  expect(stdout?.toString()).toBe(
+    `hello worldhello again|😋 Get Emoji — All Emojis to ✂️ Copy and 📋 Paste 👌`.repeat(
+      9999,
+    ),
+  );
+});
diff --git a/test/bun.js/stdio-test-instance-a-lot.js b/test/bun.js/stdio-test-instance-a-lot.js
new file mode 100644
index 000000000..2b65d786c
--- /dev/null
+++ b/test/bun.js/stdio-test-instance-a-lot.js
@@ -0,0 +1,23 @@
+import { ArrayBufferSink } from "bun";
+
+const sink = new ArrayBufferSink();
+
+sink.write("hello");
+sink.write(" ");
+sink.write("world");
+sink.write(new TextEncoder().encode("hello again|"));
+sink.write(
+  new TextEncoder().encode(
+    "😋 Get Emoji — All Emojis to ✂️ Copy and 📋 Paste 👌",
+  ),
+);
+
+const string = Buffer.from(sink.end()).toString().repeat(9999);
+
+if (process.env.TEST_STDIO_STRING) {
+  const result = string;
+  process.stdout.write(result);
+} else {
+  const result = Buffer.from(string);
+  process.stdout.write(result);
+}
diff --git a/test/bun.js/stdio-test-instance.js b/test/bun.js/stdio-test-instance.js
new file mode 100644
index 000000000..36e48f472
--- /dev/null
+++ b/test/bun.js/stdio-test-instance.js
@@ -0,0 +1,9 @@
+process.stdout.write("hello");
+process.stdout.write(" ");
+process.stdout.write("world");
+process.stdout.write(new TextEncoder().encode("hello again|"));
+process.stdout.write(
+  new TextEncoder().encode(
+    "😋 Get Emoji — All Emojis to ✂️ Copy and 📋 Paste 👌",
+  ),
+);