Handle a drive-less file URL instead of throwing

packages/launch-editor/parse-file.js

@@ -1,11 +1,23 @@
 const path = require('path')
+const { fileURLToPath } = require('url')
 
 const positionRE = /:(\d+)(:(\d+))?$/
+const windowsDriveRE = /^\/[a-z](?::|%3a)/i
 
 module.exports = function parseFile(file) {
   // support `file://` protocol
   if (file.startsWith('file://')) {
-    file = require('url').fileURLToPath(file)
+    const url = new URL(file)
+    // On Windows, `fileURLToPath` rejects file URLs without a drive letter
+    // (e.g. `file:///src/main.js`) because they are not valid Windows paths.
+    // Parse them as POSIX file URLs and let the path resolution below map
+    // them onto the current drive.
+    file =
+      process.platform === 'win32' &&
+      url.hostname === '' &&
+      !windowsDriveRE.test(url.pathname)
+        ? fileURLToPath(url, { windows: false })
+        : fileURLToPath(url)
   }
 
   const unresolvedFileName = file.replace(positionRE, '')

packages/launch-editor/parse-file.test.js

@@ -17,6 +17,14 @@ describe('launchEditor path resolution', () => {
     })
   })
 
+  test('parses file URLs without a drive letter', () => {
+    assert.deepEqual(parseFile('file:///foo/bar.js:10:5'), {
+      fileName: path.resolve('/foo/bar.js'),
+      lineNumber: '10',
+      columnNumber: '5',
+    })
+  })
+
   test('resolves a parent-directory component created by a position suffix', () => {
     const project = path.resolve('project')
     const file = `${project}${path.sep}attacker-controlled${path.sep}..:1:1`