finish file-graph and solve jest ts

packages/file-graph/src/utils.ts

@@ -0,0 +1,13 @@
+export function dirname(path: string) {
+  const parts = path.split('/')
+  if (parts.length <= 2) {
+    return '/'
+  }
+  parts.pop()
+  return parts.join('/')
+}
+
+export function basename(path: string): string {
+  const parts = path.split('/')
+  return parts.pop() ?? ''
+}