3 files changed, 78 insertions, 4 deletions
diff --git a/ext/ffi/00_ffi.js b/ext/ffi/00_ffi.js
index a63a027e8..a1b177122 100644
--- a/ext/ffi/00_ffi.js
+++ b/ext/ffi/00_ffi.js
@@ -2,7 +2,6 @@
 
 const core = globalThis.Deno.core;
 const ops = core.ops;
-const internals = globalThis.__bootstrap.internals;
 const primordials = globalThis.__bootstrap.primordials;
 const {
   ArrayPrototypeMap,
@@ -28,6 +27,7 @@ const {
   SymbolFor,
   WeakMap,
 } = primordials;
+import { pathFromURL } from "internal:deno_web/00_infra.js";
 
 const promiseIdSymbol = SymbolFor("Deno.core.internalPromiseId");
 
@@ -542,9 +542,6 @@ class DynamicLibrary {
 }
 
 function dlopen(path, symbols) {
-  // TODO(@crowlKats): remove me
-  // URL support is progressively enhanced by util in `runtime/js`.
-  const pathFromURL = internals.pathFromURL ?? ((p) => p);
   return new DynamicLibrary(pathFromURL(path), symbols);
 }
 
diff --git a/ext/ffi/lib.rs b/ext/ffi/lib.rs
index b8e3ac503..38a5a7eb2 100644
--- a/ext/ffi/lib.rs
+++ b/ext/ffi/lib.rs
@@ -83,6 +83,7 @@ pub(crate) struct FfiState {
 
 pub fn init<P: FfiPermissions + 'static>(unstable: bool) -> Extension {
   Extension::builder(env!("CARGO_PKG_NAME"))
+    .dependencies(vec!["deno_web"])
     .esm(include_js_files!("00_ffi.js",))
     .ops(vec![
       op_ffi_load::decl::<P>(),
diff --git a/ext/web/00_infra.js b/ext/web/00_infra.js
index cff0f66d8..0c062f89c 100644
--- a/ext/web/00_infra.js
+++ b/ext/web/00_infra.js
@@ -7,14 +7,17 @@
 /// <reference path="../web/lib.deno_web.d.ts" />
 
 const core = globalThis.Deno.core;
+const internals = globalThis.__bootstrap.internals;
 const ops = core.ops;
 const primordials = globalThis.__bootstrap.primordials;
 const {
   ArrayPrototypeJoin,
   ArrayPrototypeMap,
+  decodeURIComponent,
   Error,
   JSONStringify,
   NumberPrototypeToString,
+  ObjectPrototypeIsPrototypeOf,
   SafeArrayIterator,
   SafeRegExp,
   String,
@@ -29,6 +32,7 @@ const {
   StringPrototypeToUpperCase,
   TypeError,
 } = primordials;
+import { URLPrototype } from "internal:deno_url/00_url.js";
 
 const ASCII_DIGIT = ["\u0030-\u0039"];
 const ASCII_UPPER_ALPHA = ["\u0041-\u005A"];
@@ -362,6 +366,77 @@ function serializeJSValueToJSONString(value) {
   return result;
 }
 
+const PATHNAME_WIN_RE = new SafeRegExp(/^\/*([A-Za-z]:)(\/|$)/);
+const SLASH_WIN_RE = new SafeRegExp(/\//g);
+const PERCENT_RE = new SafeRegExp(/%(?![0-9A-Fa-f]{2})/g);
+
+// Keep in sync with `fromFileUrl()` in `std/path/win32.ts`.
+/**
+ * @param {URL} url
+ * @returns {string}
+ */
+function pathFromURLWin32(url) {
+  let p = StringPrototypeReplace(
+    url.pathname,
+    PATHNAME_WIN_RE,
+    "$1/",
+  );
+  p = StringPrototypeReplace(
+    p,
+    SLASH_WIN_RE,
+    "\\",
+  );
+  p = StringPrototypeReplace(
+    p,
+    PERCENT_RE,
+    "%25",
+  );
+  let path = decodeURIComponent(p);
+  if (url.hostname != "") {
+    // Note: The `URL` implementation guarantees that the drive letter and
+    // hostname are mutually exclusive. Otherwise it would not have been valid
+    // to append the hostname and path like this.
+    path = `\\\\${url.hostname}${path}`;
+  }
+  return path;
+}
+
+// Keep in sync with `fromFileUrl()` in `std/path/posix.ts`.
+/**
+ * @param {URL} url
+ * @returns {string}
+ */
+function pathFromURLPosix(url) {
+  if (url.hostname !== "") {
+    throw new TypeError(`Host must be empty.`);
+  }
+
+  return decodeURIComponent(
+    StringPrototypeReplace(
+      url.pathname,
+      PERCENT_RE,
+      "%25",
+    ),
+  );
+}
+
+function pathFromURL(pathOrUrl) {
+  if (ObjectPrototypeIsPrototypeOf(URLPrototype, pathOrUrl)) {
+    if (pathOrUrl.protocol != "file:") {
+      throw new TypeError("Must be a file URL.");
+    }
+
+    return core.build.os == "windows"
+      ? pathFromURLWin32(pathOrUrl)
+      : pathFromURLPosix(pathOrUrl);
+  }
+  return pathOrUrl;
+}
+
+// NOTE(bartlomieju): this is exposed on `internals` so we can test
+// it in unit tests
+internals.pathFromURL = pathFromURL;
+
 export {
   ASCII_ALPHA,
   ASCII_ALPHANUMERIC,
@@ -389,6 +464,7 @@ export {
   HTTP_WHITESPACE_PREFIX_RE,
   HTTP_WHITESPACE_SUFFIX_RE,
   httpTrim,
+  pathFromURL,
   regexMatcher,
   serializeJSValueToJSONString,
 };