feat(utils): add pathToFileURL

README.md

@@ -424,6 +424,20 @@ console.log(fileURLToPath("file:///foo/bar.js"));
 console.log(fileURLToPath("file:///C:/path/"));
 ```
 
+### `pathToFileURL`
+
+Similar to [url.pathToFileURL](https://nodejs.org/api/url.html#urlpathtofileurlpath) but also handles `URL` input and returns a **string** with `file://` protocol.
+
+```js
+import { pathToFileURL } from "mlly";
+
+// /foo/bar.js
+console.log(pathToFileURL("foo/bar.js"));
+
+// C:/path
+console.log(pathToFileURL("C:\\path"));
+```
+
 ### `normalizeid`
 
 Ensures id has either of `node:`, `data:`, `http:`, `https:` or `file:` protocols.

src/utils.ts

@@ -1,4 +1,7 @@
-import { fileURLToPath as _fileURLToPath } from "node:url";
+import {
+  fileURLToPath as _fileURLToPath,
+  pathToFileURL as _pathToFileURL,
+} from "node:url";
 import { promises as fsp } from "node:fs";
 import { normalizeSlash, BUILTIN_MODULES } from "./_utils";
 
@@ -9,6 +12,10 @@ export function fileURLToPath(id: string | URL): string {
   return normalizeSlash(_fileURLToPath(id));
 }
 
+export function pathToFileURL(id: string | URL): string {
+  return _pathToFileURL(fileURLToPath(id)).toString();
+}
+
 // https://datatracker.ietf.org/doc/html/rfc2396
 // eslint-disable-next-line no-control-regex
 const INVALID_CHAR_RE = /[\u0000-\u001F"#$&*+,/:;<=>?@[\]^`{|}\u007F]+/g;

test/resolve.test.ts

@@ -1,7 +1,6 @@
 import { existsSync } from "node:fs";
-import { fileURLToPath } from "node:url";
 import { describe, it, expect } from "vitest";
-import { resolveSync, resolvePathSync } from "../src";
+import { resolveSync, resolvePathSync, fileURLToPath } from "../src";
 
 const tests = [
   // Resolve to path

test/utils.test.ts

@@ -6,6 +6,8 @@ import {
   getProtocol,
   parseNodeModulePath,
   lookupNodeModuleSubpath,
+  fileURLToPath,
+  pathToFileURL,
 } from "../src";
 
 describe("isNodeBuiltin", () => {
@@ -155,3 +157,29 @@ describe("lookupNodeModuleSubpath", () => {
     });
   }
 });
+
+describe("fileURLToPath", () => {
+  const tests = [
+    // ["file:///C:/path/", "C:\\path\\"], // TODO
+    // ["file://nas/foo.txt", "\\\\nas\\foo.txt"], // TODO
+    ["file:///你好.txt", "/你好.txt"],
+    ["file:///hello world", "/hello world"],
+  ] as const;
+  for (const t of tests) {
+    it(`${t[0]} should resolve to ${t[1]}`, () => {
+      expect(fileURLToPath(t[0])).toBe(t[1]);
+    });
+  }
+});
+
+describe("pathToFileURL", () => {
+  const tests = [
+    ["/foo#1", "file:///foo%231"],
+    ["/some/path%.c", "file:///some/path%25.c"],
+  ] as const;
+  for (const t of tests) {
+    it(`${t[0]} should resolve to ${t[1]}`, () => {
+      expect(pathToFileURL(t[0])).toBe(t[1]);
+    });
+  }
+});