refactor(artifacts): isolate JavaScript file acquisition (#916)

src/artifacts/javascript/JavaScriptArtifactReader.ts

@@ -0,0 +1,12 @@
+import { AsarArtifactReader } from "../AsarArtifactReader.js";
+import type { ArtifactReader } from "../ArtifactReader.js";
+import { DirectoryArtifactReader } from "../DirectoryArtifactReader.js";
+
+/** Create the reader for an admitted JavaScript artifact format. */
+export const createJavaScriptArtifactReader = (
+  path: string,
+  format: "asar" | "directory",
+): ArtifactReader =>
+  format === "asar"
+    ? new AsarArtifactReader(path)
+    : new DirectoryArtifactReader(path);