2 files changed, 40 insertions, 2 deletions
diff --git a/src/bun.js/api/bun/subprocess.zig b/src/bun.js/api/bun/subprocess.zig
index 0444ef927..6bf839ca1 100644
--- a/src/bun.js/api/bun/subprocess.zig
+++ b/src/bun.js/api/bun/subprocess.zig
@@ -1188,7 +1188,7 @@ pub const Subprocess = struct {
                     try actions.dup2(fd, std_fileno);
                 },
                 .path => |pathlike| {
-                    const flag = if (std_fileno == std.os.STDIN_FILENO) @as(u32, os.O.WRONLY) else @as(u32, std.os.O.RDONLY);
+                    const flag = if (std_fileno == std.os.STDIN_FILENO) @as(u32, os.O.RDONLY) else @as(u32, std.os.O.WRONLY);
                     try actions.open(std_fileno, pathlike.slice(), flag | std.os.O.CREAT, 0o664);
                 },
                 .inherit => {
diff --git a/test/bun.js/spawn.test.ts b/test/bun.js/spawn.test.ts
index f7426660f..e03de2662 100644
--- a/test/bun.js/spawn.test.ts
+++ b/test/bun.js/spawn.test.ts
@@ -1,9 +1,47 @@
-import { readableStreamToText, spawn } from "bun";
+import { readableStreamToText, spawn, write } from "bun";
 import { describe, expect, it } from "bun:test";
+import { rmdirSync, unlinkSync, rmSync } from "node:fs";
 
 describe("spawn", () => {
   const hugeString = "hello".repeat(10000).slice();
 
+  it("Bun.file() works as stdout", async () => {
+    rmSync("/tmp/out.123.txt", { force: true });
+    const { exited } = spawn({
+      cmd: ["echo", "hello"],
+      stdout: Bun.file("/tmp/out.123.txt"),
+    });
+
+    await exited;
+    expect(await Bun.file("/tmp/out.123.txt").text()).toBe("hello\n");
+  });
+
+  it("Bun.file() works as stdin", async () => {
+    await write(Bun.file("/tmp/out.456.txt"), "hello there!");
+    const { stdout } = spawn({
+      cmd: ["cat"],
+      stdout: "pipe",
+      stdin: Bun.file("/tmp/out.456.txt"),
+    });
+
+    expect(await readableStreamToText(stdout)).toBe("hello there!");
+  });
+
+  it("Bun.file() works as stdin and stdout", async () => {
+    await write(Bun.file("/tmp/out.456.txt"), "hello!");
+    await write(Bun.file("/tmp/out.123.txt"), "wrong!");
+
+    const { exited } = spawn({
+      cmd: ["cat"],
+      stdout: Bun.file("/tmp/out.123.txt"),
+      stdin: Bun.file("/tmp/out.456.txt"),
+    });
+
+    await exited;
+    expect(await Bun.file("/tmp/out.456.txt").text()).toBe("hello!");
+    expect(await Bun.file("/tmp/out.123.txt").text()).toBe("hello!");
+  });
+
   it("stdout can be read", async () => {
     await Bun.write("/tmp/out.txt", hugeString);
     const { stdout } = spawn({