fix(node): make `process.stdout.isTTY` writable (#26130)

Fixes https://github.com/denoland/deno/issues/26123

1 files changed, 9 insertions, 1 deletions

diff --git a/ext/node/polyfills/_process/streams.mjs b/ext/node/polyfills/_process/streams.mjs
index 19c1c9c18..7936e82aa 100644
--- a/ext/node/polyfills/_process/streams.mjs
+++ b/ext/node/polyfills/_process/streams.mjs
@@ -63,6 +63,10 @@ export function createWritableStdioStream(writer, name, warmup = false) {
   stream.destroySoon = stream.destroy;
   stream._isStdio = true;
   stream.once("close", () => writer?.close());
+
+  // We cannot call `writer?.isTerminal()` eagerly here
+  let getIsTTY = () => writer?.isTerminal();
+
   ObjectDefineProperties(stream, {
     columns: {
       __proto__: null,
@@ -81,7 +85,11 @@ export function createWritableStdioStream(writer, name, warmup = false) {
       __proto__: null,
       enumerable: true,
       configurable: true,
-      get: () => writer?.isTerminal(),
+      // Allow users to overwrite it
+      get: () => getIsTTY(),
+      set: (value) => {
+        getIsTTY = () => value;
+      },
     },
     getWindowSize: {
       __proto__: null,