Fixes #5465 (#5468)

* Fixes #5465

Fixes #5465

* Update tty.js

* Update InternalModuleRegistryConstants.h

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/test/js/node/tt.y.test.ts b/test/js/node/tt.y.test.ts
new file mode 100644
index 000000000..c1723ad48
--- /dev/null
+++ b/test/js/node/tt.y.test.ts
@@ -0,0 +1,25 @@
+import { describe, it, expect } from "bun:test";
+import { WriteStream } from "node:tty";
+
+describe("WriteStream.prototype.getColorDepth", () => {
+  it("iTerm ancient", () => {
+    expect(
+      WriteStream.prototype.getColorDepth.call(undefined, {
+        TERM_PROGRAM: "iTerm.app",
+      }),
+    ).toBe(8);
+  });
+
+  it("iTerm modern", () => {
+    expect(
+      WriteStream.prototype.getColorDepth.call(undefined, {
+        TERM_PROGRAM: "iTerm.app",
+        TERM_PROGRAM_VERSION: 3,
+      }),
+    ).toBe(24);
+  });
+
+  it("empty", () => {
+    expect(WriteStream.prototype.getColorDepth.call(undefined, {})).toBe(1);
+  });
+});