diff --git a/test/common/README.md b/test/common/README.md
index 009263a7c4fd0b..515e92325edb4d 100644
--- a/test/common/README.md
+++ b/test/common/README.md
@@ -1027,11 +1027,15 @@ The `tmpdir` module supports the use of a temporary directory for testing.
 
 The realpath of the testing temporary directory.
 
-### `url`
+### `fileURL([...paths])`
 
-* [\<string>][<string>]
+* `...paths` [\<string>][<string>]
+* return [\<URL>][<URL>]
+
+Resolves a sequence of paths into absolute url in the temporary directory.
 
-The absolute url of the testing temporary directory with trailing `/`.
+When called without arguments, returns absolute url of the testing
+temporary directory with explicit trailing `/`.
 
 ### `refresh(useSpawn)`
 
@@ -1098,6 +1102,7 @@ See [the WPT tests README][] for details.
 [<Function>]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function
 [<Object>]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object
 [<RegExp>]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp
+[<URL>]: https://developer.mozilla.org/en-US/docs/Web/API/URL
 [<any>]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types
 [<bigint>]: https://github.com/tc39/proposal-bigint
 [<boolean>]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type