feat(ext/node): Promisify fstat and implement FileHandle#stat

ext/node/polyfills/_fs/_fs_common.ts

@@ -243,3 +243,5 @@ export function makeCallback(
 
   return (...args: unknown[]) => Reflect.apply(cb!, this, args);
 }
+
+export type { BigIntStats, Stats } from "ext:deno_node/_fs/_fs_stat.ts";

ext/node/polyfills/_fs/_fs_fstat.ts

@@ -63,3 +63,24 @@ export function fstatSync(
   const origin = new FsFile(fd, Symbol.for("Deno.internal.FsFile")).statSync();
   return CFISBIS(origin, options?.bigint || false);
 }
+
+export function fstatPromise(fd: number): Promise<Stats>;
+export function fstatPromise(
+  fd: number,
+  options: { bigint: false },
+): Promise<Stats>;
+export function fstatPromise(
+  fd: number,
+  options: { bigint: true },
+): Promise<BigIntStats>;
+export function fstatPromise(
+  fd: number,
+  options?: statOptions,
+): Stats | BigIntStats {
+  return new Promise((resolve, reject) => {
+    fstat(fd, options, (err, stats) => {
+      if (err) reject(err);
+      else resolve(stats);
+    });
+  });
+}

ext/node/polyfills/fs.ts

@@ -23,7 +23,7 @@ import Dir from "ext:deno_node/_fs/_fs_dir.ts";
 import Dirent from "ext:deno_node/_fs/_fs_dirent.ts";
 import { exists, existsSync } from "ext:deno_node/_fs/_fs_exists.ts";
 import { fdatasync, fdatasyncSync } from "ext:deno_node/_fs/_fs_fdatasync.ts";
-import { fstat, fstatSync } from "ext:deno_node/_fs/_fs_fstat.ts";
+import { fstat, fstatPromise, fstatSync } from "ext:deno_node/_fs/_fs_fstat.ts";
 import { fsync, fsyncSync } from "ext:deno_node/_fs/_fs_fsync.ts";
 import { ftruncate, ftruncateSync } from "ext:deno_node/_fs/_fs_ftruncate.ts";
 import { futimes, futimesSync } from "ext:deno_node/_fs/_fs_futimes.ts";
@@ -174,6 +174,7 @@ const promises = {
   lstat: lstatPromise,
   stat: statPromise,
   statfs: statfsPromise,
+  fstat: fstatPromise,
   link: linkPromise,
   unlink: unlinkPromise,
   chmod: chmodPromise,

ext/node/polyfills/fs/promises.ts

@@ -16,6 +16,7 @@ export const readlink = fsPromises.readlink;
 export const symlink = fsPromises.symlink;
 export const lstat = fsPromises.lstat;
 export const stat = fsPromises.stat;
+export const fstat = fsPromises.fstat;
 export const link = fsPromises.link;
 export const unlink = fsPromises.unlink;
 export const chmod = fsPromises.chmod;

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

@@ -7,9 +7,11 @@ import { EventEmitter } from "node:events";
 import { Buffer } from "node:buffer";
 import { promises, read, write } from "node:fs";
 import {
+  BigIntStats,
   BinaryOptionsArgument,
   FileOptionsArgument,
   ReadOptions,
+  Stats,
   TextOptionsArgument,
 } from "ext:deno_node/_fs/_fs_common.ts";
 import { core } from "ext:core/mod.js";
@@ -141,6 +143,13 @@ export class FileHandle extends EventEmitter {
     // Note that Deno.close is not async
     return Promise.resolve(core.close(this.fd));
   }
+
+  stat(): Promise<Stats>;
+  stat(options: { bigint: false }): Promise<Stats>;
+  stat(options: { bigint: true }): Promise<BigIntStats>;
+  stat(options?: { bigint: boolean }): Promise<Stats | BigIntStats> {
+    return fsCall(promises.fstat, this, options);
+  }
 }
 
 function fsCall(fn, handle, ...args) {
@@ -152,7 +161,7 @@ function fsCall(fn, handle, ...args) {
     });
   }
 
-  return fn(handle, ...args);
+  return fn(handle.fd, ...args);
 }
 
 export default {

tests/unit_node/_fs/_fs_handle_test.ts

@@ -93,3 +93,27 @@ Deno.test("[node/fs filehandle.write] Write from string", async function () {
   assertEquals(res.bytesWritten, 11);
   assertEquals(decoder.decode(data), "hello world");
 });
+
+Deno.test("[node/fs filehandle.stat] Get file status", async function () {
+  const fileHandle = await fs.open(testData);
+  const stat = await fileHandle.stat();
+
+  assertEquals(stat.isFile(), true);
+  assertEquals(stat.size, "hello world".length);
+
+  await fileHandle.close();
+});
+
+Deno.test("[node/fs filehandle.writeFile] Write to file", async function () {
+  const tempFile: string = await Deno.makeTempFile();
+  const fileHandle = await fs.open(tempFile, "w");
+
+  const str = "hello world";
+  await fileHandle.writeFile(str);
+
+  const data = Deno.readFileSync(tempFile);
+  await Deno.remove(tempFile);
+  await fileHandle.close();
+
+  assertEquals(decoder.decode(data), "hello world");
+});