Fix getModule so it correctly handles Windows paths

Author: timfish

packages/node/src/module.ts

@@ -6,15 +6,19 @@ export function getModule(filename: string | undefined): string | undefined {
     return;
   }
 
+  const normalizedFilename = filename
+    .replace(/^[A-Z]:/, '') // remove Windows-style prefix
+    .replace(/\\/g, '/'); // replace all `\` instances with `/`;
+
   // We could use optional chaining here but webpack does like that mixed with require
   const base = `${
     (require && require.main && require.main.filename && dirname(require.main.filename)) || global.process.cwd()
   }/`;
 
   // It's specifically a module
-  const file = basename(filename, '.js');
+  const file = basename(normalizedFilename, '.js');
 
-  const path = dirname(filename);
+  const path = dirname(normalizedFilename);
   let n = path.lastIndexOf('/node_modules/');
   if (n > -1) {
     // /node_modules/ is 14 chars