fix(artifacts): verify MFT source before publishing metadata

Co-authored-by: gensokyo-dev <342580529+gensokyo-dev@users.noreply.github.com>

src/artifacts/NtfsMftArtifactReader.test.ts

@@ -1,7 +1,10 @@
 import { writeFile } from "node:fs/promises";
 import { join } from "node:path";
 
-import { expect, it } from "vitest";
+import { expect, it, vi } from "vitest";
+
+import { ArtifactFileSource } from "./ArtifactFileSource.js";
+import { NtfsMftArtifactReader } from "./NtfsMftArtifactReader.js";
 
 import { MFT_DEFAULT_RECORD_BYTES } from "../domain/windows/ntfsMft.js";
 import { createTestTempDirectory } from "../../tests/fixtures/temporaryDirectory.js";
@@ -98,3 +101,25 @@ it("reports incomplete coverage when FILE extents contradict the record slots",
     fixup_unverified_record_count: 0,
   });
 });
+
+it("does not publish metadata when final source verification fails", async () => {
+  const reader = new NtfsMftArtifactReader(
+    await writeMft("$MFT", recordBytes({})),
+  );
+  const read = ArtifactFileSource.prototype.read;
+  const spy = vi
+    .spyOn(ArtifactFileSource.prototype, "read")
+    .mockImplementationOnce(function (this: ArtifactFileSource, signal) {
+      return read.call(this, signal);
+    })
+    .mockRejectedValueOnce(new Error("final source verification failed"));
+  try {
+    await expect(reader.entries().next()).rejects.toThrow(
+      "final source verification failed",
+    );
+    expect(reader.formatMetadata()).toBeUndefined();
+  } finally {
+    spy.mockRestore();
+    await reader.close();
+  }
+});

src/artifacts/NtfsMftArtifactReader.ts

@@ -93,9 +93,9 @@ export class NtfsMftArtifactReader implements ArtifactReader {
 
   async #prepare(signal?: AbortSignal): Promise<void> {
     const image = await this.#decode(signal);
+    await this.#source.read(signal);
     this.#metadata = image.metadata;
     this.#limitations = image.limitations;
-    await this.#source.read(signal);
   }
 
   async #decode(signal?: AbortSignal): Promise<MftImage> {