feat(fs/unstable): add statSync and lstatSync (#6300)

Author: kt3k

_tools/check_docs.ts

@@ -62,6 +62,9 @@ const ENTRY_POINTS = [
   "../front_matter/mod.ts",
   "../front_matter/unstable_yaml.ts",
   "../fs/mod.ts",
+  "../fs/unstable_lstat.ts",
+  "../fs/unstable_stat.ts",
+  "../fs/unstable_types.ts",
   "../html/mod.ts",
   "../html/unstable_is_valid_custom_element_name.ts",
   "../http/mod.ts",

fs/_utils.ts

@@ -21,6 +21,9 @@ function checkWindows(): boolean {
   return false;
 }
 
-export function getNodeFsPromises() {
-  return (globalThis as any).process.getBuiltinModule("node:fs/promises");
+/**
+ * @returns The Node.js `fs` module.
+ */
+export function getNodeFs() {
+  return (globalThis as any).process.getBuiltinModule("node:fs");
 }

fs/deno.json

@@ -13,8 +13,9 @@
     "./exists": "./exists.ts",
     "./expand-glob": "./expand_glob.ts",
     "./move": "./move.ts",
-    "./unstable-stat": "./unstable_stat.ts",
     "./unstable-lstat": "./unstable_lstat.ts",
+    "./unstable-stat": "./unstable_stat.ts",
+    "./unstable-types": "./unstable_types.ts",
     "./walk": "./walk.ts"
   }
 }

fs/unstable_lstat.ts

@@ -1,32 +1,68 @@
 // Copyright 2018-2025 the Deno authors. MIT license.
 
-import { getNodeFsPromises, isDeno } from "./_utils.ts";
+import { getNodeFs, isDeno } from "./_utils.ts";
 import { mapError } from "./_map_error.ts";
 import { toFileInfo } from "./_to_file_info.ts";
 import type { FileInfo } from "./unstable_types.ts";
 
-/** Resolves to a {@linkcode FileInfo} for the specified `path`. If `path` is a symlink, information for the symlink will be returned instead of what it points to.
+/**
+ * Resolves to a {@linkcode FileInfo} for the specified `path`. If `path` is a symlink, information for the symlink will be returned instead of what it points to.
  *
+ * Requires `allow-read` permission in Deno.
+ *
+ * @example Usage
  * ```ts
  * import { assert } from "@std/assert";
  * import { lstat } from "@std/fs/unstable-lstat";
  * const fileInfo = await lstat("README.md");
  * assert(fileInfo.isFile);
  * ```
  *
- * Requires `allow-read` permission.
- *
  * @tags allow-read
- * @category File System
+ *
+ * @param path The path to the file or directory.
+ * @returns A promise that resolves to a {@linkcode FileInfo} for the specified `path`.
  */
 export async function lstat(path: string | URL): Promise<FileInfo> {
   if (isDeno) {
     return Deno.lstat(path);
   } else {
-    const fsPromises = getNodeFsPromises();
     try {
-      const stat = await fsPromises.lstat(path);
-      return toFileInfo(stat);
+      return toFileInfo(await getNodeFs().promises.lstat(path));
+    } catch (error) {
+      throw mapError(error);
+    }
+  }
+}
+
+/**
+ * Synchronously returns a {@linkcode FileInfo} for the specified
+ * `path`. If `path` is a symlink, information for the symlink will be
+ * returned instead of what it points to.
+ *
+ * Requires `allow-read` permission in Deno.
+ *
+ * @example Usage
+ *
+ * ```ts
+ * import { assert } from "@std/assert";
+ * import { lstatSync } from "@std/fs/unstable-lstat";
+ *
+ * const fileInfo = lstatSync("README.md");
+ * assert(fileInfo.isFile);
+ * ```
+ *
+ * @tags allow-read
+ *
+ * @param path The path to the file or directory.
+ * @returns A {@linkcode FileInfo} for the specified `path`.
+ */
+export function lstatSync(path: string | URL): FileInfo {
+  if (isDeno) {
+    return Deno.lstatSync(path);
+  } else {
+    try {
+      return toFileInfo(getNodeFs().lstatSync(path));
     } catch (error) {
       throw mapError(error);
     }

fs/unstable_lstat_test.ts

@@ -1,30 +1,48 @@
 // Copyright 2018-2025 the Deno authors. MIT license.
 
-import { assert, assertRejects } from "@std/assert";
-import { lstat } from "./unstable_lstat.ts";
+import { assert, assertRejects, assertThrows } from "@std/assert";
+import { lstat, lstatSync } from "./unstable_lstat.ts";
 import { NotFound } from "./unstable_errors.js";
 
-Deno.test("lstat() returns FileInfo for a file", async () => {
-  const fileInfo = await lstat("README.md");
-
-  assert(fileInfo.isFile);
+Deno.test("lstat() and lstatSync() return FileInfo for a file", async () => {
+  {
+    const fileInfo = await lstat("README.md");
+    assert(fileInfo.isFile);
+  }
+  {
+    const fileInfo = lstatSync("README.md");
+    assert(fileInfo.isFile);
+  }
 });
 
-Deno.test("lstat() does not follow symlinks", async () => {
-  const linkFile = `${import.meta.dirname}/testdata/0-link`;
-  const fileInfo = await lstat(linkFile);
-
-  assert(fileInfo.isSymlink);
+Deno.test("lstat() and lstatSync() do not follow symlinks", async () => {
+  const linkFile = new URL("testdata/0-link", import.meta.url);
+  {
+    const fileInfo = await lstat(linkFile);
+    assert(fileInfo.isSymlink);
+  }
+  {
+    const fileInfo = lstatSync(linkFile);
+    assert(fileInfo.isSymlink);
+  }
 });
 
-Deno.test("lstat() returns FileInfo for a directory", async () => {
-  const fileInfo = await lstat("fs");
-
-  assert(fileInfo.isDirectory);
+Deno.test("lstat() and lstatSync() return FileInfo for a directory", async () => {
+  {
+    const fileInfo = await lstat("fs");
+    assert(fileInfo.isDirectory);
+  }
+  {
+    const fileInfo = lstatSync("fs");
+    assert(fileInfo.isDirectory);
+  }
 });
 
-Deno.test("lstat() rejects with NotFound for a non-existent file", async () => {
+Deno.test("lstat() and lstatSync() throw with NotFound for a non-existent file", async () => {
   await assertRejects(async () => {
     await lstat("non_existent_file");
   }, NotFound);
+  assertThrows(() => {
+    lstatSync("non_existent_file");
+  }, NotFound);
 });

fs/unstable_stat.ts

@@ -1,33 +1,67 @@
 // Copyright 2018-2025 the Deno authors. MIT license.
 
-import { getNodeFsPromises, isDeno } from "./_utils.ts";
+import { getNodeFs, isDeno } from "./_utils.ts";
 import { mapError } from "./_map_error.ts";
 import { toFileInfo } from "./_to_file_info.ts";
 import type { FileInfo } from "./unstable_types.ts";
 
-/** Resolves to a {@linkcode FileInfo} for the specified `path`. Will
+/**
+ * Resolves to a {@linkcode FileInfo} for the specified `path`. Will
  * always follow symlinks.
  *
+ * Requires `allow-read` permission in Deno.
+ *
+ * @example Usage
  * ```ts
  * import { assert } from "@std/assert";
  * import { stat } from "@std/fs/unstable-stat";
  * const fileInfo = await stat("README.md");
  * assert(fileInfo.isFile);
  * ```
  *
- * Requires `allow-read` permission.
- *
  * @tags allow-read
- * @category File System
+ *
+ * @param path The path to the file or directory.
+ * @returns A promise that resolves to a {@linkcode FileInfo} for the specified `path`.
  */
 export async function stat(path: string | URL): Promise<FileInfo> {
   if (isDeno) {
     return Deno.stat(path);
   } else {
-    const fsPromises = getNodeFsPromises();
     try {
-      const stat = await fsPromises.stat(path);
-      return toFileInfo(stat);
+      return toFileInfo(await getNodeFs().promises.stat(path));
+    } catch (error) {
+      throw mapError(error);
+    }
+  }
+}
+
+/**
+ * Synchronously returns a {@linkcode FileInfo} for the specified
+ * `path`. Will always follow symlinks.
+ *
+ * Requires `allow-read` permission in Deno.
+ *
+ * @example Usage
+ * ```ts
+ * import { assert } from "@std/assert";
+ * import { statSync } from "@std/fs/unstable-stat";
+ *
+ * const fileInfo = statSync("README.md");
+ * assert(fileInfo.isFile);
+ * ```
+ *
+ * @tags allow-read
+ *
+ * @param path The path to the file or directory.
+ * @returns A {@linkcode FileInfo} for the specified `path`.
+ */
+export function statSync(path: string | URL): FileInfo {
+  if (isDeno) {
+    return Deno.statSync(path);
+  } else {
+    try {
+      return toFileInfo(getNodeFs().statSync(path));
     } catch (error) {
       throw mapError(error);
     }

fs/unstable_stat_test.ts

@@ -1,23 +1,37 @@
 // Copyright 2018-2025 the Deno authors. MIT license.
 
-import { assert, assertRejects } from "@std/assert";
-import { stat } from "./unstable_stat.ts";
+import { assert, assertRejects, assertThrows } from "@std/assert";
+import { stat, statSync } from "./unstable_stat.ts";
 import { NotFound } from "./unstable_errors.js";
 
-Deno.test("stat() returns FileInfo for a file", async () => {
-  const fileInfo = await stat("README.md");
+Deno.test("stat() and statSync() return FileInfo for a file", async () => {
+  {
+    const fileInfo = await stat("README.md");
+    assert(fileInfo.isFile);
+  }
 
-  assert(fileInfo.isFile);
+  {
+    const fileInfo = statSync("README.md");
+    assert(fileInfo.isFile);
+  }
 });
 
-Deno.test("stat() returns FileInfo for a directory", async () => {
-  const fileInfo = await stat("fs");
-
-  assert(fileInfo.isDirectory);
+Deno.test("stat() and statSync() return FileInfo for a directory", async () => {
+  {
+    const fileInfo = await stat("fs");
+    assert(fileInfo.isDirectory);
+  }
+  {
+    const fileInfo = statSync("fs");
+    assert(fileInfo.isDirectory);
+  }
 });
 
-Deno.test("stat() rejects with NotFound for a non-existent file", async () => {
+Deno.test("stat() and statSync() throw with NotFound for a non-existent file", async () => {
   await assertRejects(async () => {
     await stat("non_existent_file");
   }, NotFound);
+  assertThrows(() => {
+    statSync("non_existent_file");
+  }, NotFound);
 });

fs/unstable_types.ts

@@ -1,5 +1,13 @@
 // Copyright 2018-2025 the Deno authors. MIT license.
 
+/**
+ * Provides information about a file and is returned by
+ * {@linkcode stat}, {@linkcode lstat}, {@linkcode statSync},
+ * and {@linkcode lstatSync} or from calling `stat()` and `statSync()`
+ * on an {@linkcode FsFile} instance.
+ *
+ * @category File System
+ */
 export interface FileInfo {
   /** True if this is info for a regular file. Mutually exclusive to
    * `FileInfo.isDirectory` and `FileInfo.isSymlink`. */