Release Archive Tools 0.2.0

tests/archive/tar-gzip.test.ts

@@ -1,7 +1,11 @@
 // @vitest-environment node
 import { File } from "node:buffer";
 import { describe, expect, it } from "vitest";
-import { gzipDeterministic, gunzipBounded } from "../../src/archive/gzip";
+import {
+  gzipDeterministic,
+  gunzipBounded,
+  gunzipBoundedDetailed,
+} from "../../src/archive/gzip";
 import { createTar, parseTar } from "../../src/archive/tar";
 
 function input(path: string, text: string) {
@@ -73,16 +77,81 @@ describe("TAR, USTAR, PAX and gzip", () => {
     expect(() => gunzipBounded(compressed, 1024)).toThrow(/expanded-byte/iu);
   });
 
-  it("explicitly rejects concatenated gzip members", () => {
+  it("decodes concatenated gzip members and validates each footer", () => {
     const left = gzipDeterministic(new TextEncoder().encode("left"));
     const right = gzipDeterministic(new TextEncoder().encode("right"));
     const joined = new Uint8Array(left.length + right.length);
     joined.set(left);
     joined.set(right, left.length);
-    expect(() => gunzipBounded(joined, 1024)).toThrow(/multi-member/iu);
+    expect(new TextDecoder().decode(gunzipBounded(joined, 1024))).toBe(
+      "leftright",
+    );
+    expect(gunzipBoundedDetailed(joined, 1024).members).toMatchObject([
+      { index: 0, expandedBytes: 4 },
+      { index: 1, expandedBytes: 5 },
+    ]);
+    joined[left.length - 8] = joined[left.length - 8]! ^ 1;
+    expect(() => gunzipBounded(joined, 1024)).toThrow(/member 1/iu);
+  });
+
+  it("reads bounded GNU long-name and long-link metadata", async () => {
+    const regular = await createTar([input("placeholder", "data")]);
+    const longPath = `${"gnu/".repeat(35)}entry.txt`;
+    const named = prependGnuMetadata(regular, 0x4c, longPath);
+    expect(parseTar(named).entries[0]?.path).toBe(longPath);
+
+    const linkTarget = `${"target/".repeat(24)}file.txt`;
+    const linked = prependGnuMetadata(regular.slice(), 0x4b, linkTarget);
+    linked[512 + paddedPayloadSize(linkTarget) + 156] = 0x32;
+    rewriteChecksum(
+      linked.subarray(
+        512 + paddedPayloadSize(linkTarget),
+        1024 + paddedPayloadSize(linkTarget),
+      ),
+    );
+    expect(parseTar(linked).entries[0]).toMatchObject({
+      kind: "symlink",
+      linkTarget,
+      extractable: false,
+    });
   });
 });
 
+function paddedPayloadSize(value: string): number {
+  return (
+    Math.ceil(new TextEncoder().encode(`${value}\0`).byteLength / 512) * 512
+  );
+}
+
+function prependGnuMetadata(
+  tar: Uint8Array,
+  type: number,
+  value: string,
+): Uint8Array {
+  const payload = new TextEncoder().encode(`${value}\0`);
+  const padded = Math.ceil(payload.byteLength / 512) * 512;
+  const output = new Uint8Array(512 + padded + tar.byteLength);
+  const header = output.subarray(0, 512);
+  header.set(new TextEncoder().encode("././@LongLink"), 0);
+  header.set(new TextEncoder().encode("0000644\0"), 100);
+  header.set(new TextEncoder().encode("0000000\0"), 108);
+  header.set(new TextEncoder().encode("0000000\0"), 116);
+  header.set(
+    new TextEncoder().encode(
+      `${payload.byteLength.toString(8).padStart(11, "0")}\0`,
+    ),
+    124,
+  );
+  header.set(new TextEncoder().encode("00000000000\0"), 136);
+  header[156] = type;
+  header.set(new TextEncoder().encode("ustar\0"), 257);
+  header.set(new TextEncoder().encode("00"), 263);
+  rewriteChecksum(header);
+  output.set(payload, 512);
+  output.set(tar, 512 + padded);
+  return output;
+}
+
 function rewriteChecksum(header: Uint8Array) {
   header.fill(0x20, 148, 156);
   const checksum = header.reduce((sum, byte) => sum + byte, 0);