cleanup logic

Author: fraidev

ext/node/polyfills/fs.ts

@@ -111,6 +111,7 @@ import {
 } from "ext:core/ops";
 import {
   getRid,
+  hasFd,
   registerFd,
   unregisterFd,
 } from "ext:deno_node/internal/fs/fd_map.ts";
@@ -2215,7 +2216,11 @@ async function _writeFileGetOpenInfo(
   flag: string = "w",
 ): Promise<{ rid: number; openedFd: number | null }> {
   if (typeof pathOrRid === "number") {
-    return { rid: getRid(pathOrRid), openedFd: null };
+    // If fd is not yet mapped, getRid will dup it (creating a new rid).
+    // Track that so the caller can clean up the dup'd rid.
+    const wasMapped = hasFd(pathOrRid);
+    const rid = getRid(pathOrRid);
+    return { rid, openedFd: wasMapped ? null : pathOrRid };
   }
   try {
     const { rid, fd } = await op_node_open(
@@ -2238,7 +2243,11 @@ function _writeFileGetOpenInfoSync(
   flag: string = "w",
 ): { rid: number; openedFd: number | null } {
   if (typeof pathOrRid === "number") {
-    return { rid: getRid(pathOrRid), openedFd: null };
+    // If fd is not yet mapped, getRid will dup it (creating a new rid).
+    // Track that so the caller can clean up the dup'd rid.
+    const wasMapped = hasFd(pathOrRid);
+    const rid = getRid(pathOrRid);
+    return { rid, openedFd: wasMapped ? null : pathOrRid };
   }
   try {
     const { rid, fd } = op_node_open_sync(

ext/node/polyfills/internal/fs/fd_map.ts

@@ -60,6 +60,10 @@ export function getRid(fd: number): number {
   return fd;
 }
 
+export function hasFd(fd: number): boolean {
+  return MapPrototypeGet(fdMap, fd) !== undefined;
+}
+
 export function unregisterFd(fd: number): void {
   MapPrototypeDelete(fdMap, fd);
 }

tests/specs/node/node_fs_write_file_fd/__test__.jsonc

@@ -0,0 +1,4 @@
+{
+  "args": "run --allow-read --allow-write main.ts",
+  "output": "main.out"
+}

tests/specs/node/node_fs_write_file_fd/main.out

@@ -0,0 +1,5 @@
+sync: sync write via fdsync overwrite
+async: async write via fdasync overwrite
+path: via path
+multi: write 0write 1write 2write 3write 4write 5write 6write 7write 8write 9
+ok

tests/specs/node/node_fs_write_file_fd/main.ts

@@ -0,0 +1,50 @@
+import { closeSync, openSync, readFileSync, writeFileSync } from "node:fs";
+import { writeFile } from "node:fs/promises";
+
+const tmp = Deno.makeTempDirSync();
+
+// Test 1: writeFileSync with a numeric fd cleans up properly
+{
+  const path = `${tmp}/sync.txt`;
+  Deno.writeTextFileSync(path, "");
+  const fd = openSync(path, "w");
+  writeFileSync(fd, "sync write via fd");
+  // fd should still be usable after writeFileSync (not closed)
+  writeFileSync(fd, "sync overwrite");
+  closeSync(fd);
+  console.log("sync:", readFileSync(path, "utf8"));
+}
+
+// Test 2: writeFile (async) with a numeric fd cleans up properly
+{
+  const path = `${tmp}/async.txt`;
+  Deno.writeTextFileSync(path, "");
+  const fd = openSync(path, "w");
+  await writeFile(fd, "async write via fd");
+  // fd should still be usable after writeFile
+  await writeFile(fd, "async overwrite");
+  closeSync(fd);
+  console.log("async:", readFileSync(path, "utf8"));
+}
+
+// Test 3: writeFileSync with a path (string) still works
+{
+  const path = `${tmp}/path.txt`;
+  writeFileSync(path, "via path");
+  console.log("path:", readFileSync(path, "utf8"));
+}
+
+// Test 4: multiple writeFileSync calls with same fd don't leak
+{
+  const path = `${tmp}/multi.txt`;
+  Deno.writeTextFileSync(path, "");
+  const fd = openSync(path, "w");
+  for (let i = 0; i < 10; i++) {
+    writeFileSync(fd, `write ${i}`);
+  }
+  closeSync(fd);
+  console.log("multi:", readFileSync(path, "utf8"));
+}
+
+Deno.removeSync(tmp, { recursive: true });
+console.log("ok");