initial commit. phase 1 complete

frontend/node_modules/@jridgewell/trace-mapping/src/resolve.ts

@@ -0,0 +1,16 @@
+import resolveUri from '@jridgewell/resolve-uri';
+import stripFilename from './strip-filename';
+
+type Resolve = (source: string | null) => string;
+export default function resolver(
+  mapUrl: string | null | undefined,
+  sourceRoot: string | undefined,
+): Resolve {
+  const from = stripFilename(mapUrl);
+  // The sourceRoot is always treated as a directory, if it's not empty.
+  // https://github.com/mozilla/source-map/blob/8cb3ee57/lib/util.js#L327
+  // https://github.com/chromium/chromium/blob/da4adbb3/third_party/blink/renderer/devtools/front_end/sdk/SourceMap.js#L400-L401
+  const prefix = sourceRoot ? sourceRoot + '/' : '';
+
+  return (source) => resolveUri(prefix + (source || ''), from);
+}