feat(std/node/fs): add realpath and realpathSync (#8169)

std/node/_fs/_fs_realpath.ts

@@ -0,0 +1,22 @@
+type Options = { encoding: string };
+type Callback = (err: Error | null, path?: string) => void;
+
+export function realpath(
+  path: string,
+  options?: Options | Callback,
+  callback?: Callback,
+) {
+  if (typeof options === "function") {
+    callback = options;
+  }
+  if (!callback) {
+    throw new Error("No callback function supplied");
+  }
+  Deno.realPath(path)
+    .then((path) => callback!(null, path))
+    .catch((err) => callback!(err));
+}
+
+export function realpathSync(path: string): string {
+  return Deno.realPathSync(path);
+}

std/node/_fs/_fs_realpath_test.ts

@@ -0,0 +1,36 @@
+import { assertEquals } from "../../testing/asserts.ts";
+import { realpath, realpathSync } from "./_fs_realpath.ts";
+
+Deno.test("realpath", async function () {
+  const tempFile = await Deno.makeTempFile();
+  const tempFileAlias = tempFile + ".alias";
+  await Deno.symlink(tempFile, tempFileAlias);
+  const realPath = await new Promise((resolve, reject) => {
+    realpath(tempFile, (err, path) => {
+      if (err) {
+        reject(err);
+        return;
+      }
+      resolve(path);
+    });
+  });
+  const realSymLinkPath = await new Promise((resolve, reject) => {
+    realpath(tempFileAlias, (err, path) => {
+      if (err) {
+        reject(err);
+        return;
+      }
+      resolve(path);
+    });
+  });
+  assertEquals(realPath, realSymLinkPath);
+});
+
+Deno.test("realpathSync", function () {
+  const tempFile = Deno.makeTempFileSync();
+  const tempFileAlias = tempFile + ".alias";
+  Deno.symlinkSync(tempFile, tempFileAlias);
+  const realPath = realpathSync(tempFile);
+  const realSymLinkPath = realpathSync(tempFileAlias);
+  assertEquals(realPath, realSymLinkPath);
+});

std/node/fs.ts

@@ -12,6 +12,7 @@ import { mkdir, mkdirSync } from "./_fs/_fs_mkdir.ts";
 import { copyFile, copyFileSync } from "./_fs/_fs_copy.ts";
 import { writeFile, writeFileSync } from "./_fs/_fs_writeFile.ts";
 import { readdir, readdirSync } from "./_fs/_fs_readdir.ts";
+import { realpath, realpathSync } from "./_fs/_fs_realpath.ts";
 import { rename, renameSync } from "./_fs/_fs_rename.ts";
 import { rmdir, rmdirSync } from "./_fs/_fs_rmdir.ts";
 import { unlink, unlinkSync } from "./_fs/_fs_unlink.ts";
@@ -51,6 +52,8 @@ export {
   readFileSync,
   readlink,
   readlinkSync,
+  realpath,
+  realpathSync,
   rename,
   renameSync,
   rmdir,