Tweak CommonJS output (#3320)

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

1 files changed, 65 insertions, 0 deletions

diff --git a/bench/snippets/module-exports-putter.cjs b/bench/snippets/module-exports-putter.cjs
new file mode 100644
index 000000000..9bef17b90
--- /dev/null
+++ b/bench/snippets/module-exports-putter.cjs
@@ -0,0 +1,65 @@
+// This is a stress test of some internals in How Bun does the module.exports assignment.
+// If it crashes or throws then this fails
+import("./runner.mjs").then(({ bench, run }) => {
+  bench("Object.defineProperty(module, 'exports', { get() { return 42; } })", () => {
+    Object.defineProperty(module, "exports", {
+      get() {
+        return 42;
+      },
+      set() {
+        throw new Error("bad");
+      },
+      configurable: true,
+    });
+    if (module.exports !== 42) throw new Error("bad");
+    if (!Object.getOwnPropertyDescriptor(module, "exports").get) throw new Error("bad");
+  });
+
+  bench("Object.defineProperty(module.exports = {})", () => {
+    Object.defineProperty(module, "exports", {
+      value: { abc: 123 },
+    });
+
+    if (!module.exports.abc) throw new Error("bad");
+    if (Object.getOwnPropertyDescriptor(module, "exports").value !== module.exports) throw new Error("bad");
+  });
+
+  bench("module.exports = {}", () => {
+    module.exports = { abc: 123 };
+
+    if (!module.exports.abc) throw new Error("bad");
+    if (Object.getOwnPropertyDescriptor(module, "exports").value !== module.exports) throw new Error("bad");
+  });
+
+  run().then(() => {
+    module.exports = {
+      a: 1,
+    };
+
+    console.log(
+      module?.exports,
+      require.cache[module.id].exports,
+      module?.exports === require.cache[module.id],
+      __dirname,
+      Object.keys(require(module.id)),
+      require(module.id),
+    );
+
+    module.exports = function lol() {
+      return 42;
+    };
+
+    console.log(module.exports, module.exports());
+
+    queueMicrotask(() => {
+      console.log(
+        module?.exports,
+        require.cache[module.id].exports,
+        module?.exports === require.cache[module.id]?.exports,
+        __dirname,
+        Object.keys(require(module.id)),
+        require(module.id),
+      );
+    });
+  });
+});