node: fix test-zlib-from-gzip-with-trailing-garbage.js (#15757)

src/bun.js/node/node_zlib_binding.zig

@@ -497,7 +497,17 @@ const ZlibContext = struct {
         return .{
             .msg = message,
             .err = @intFromEnum(this.err),
-            .code = @tagName(this.err),
+            .code = switch (this.err) {
+                .Ok => "Z_OK",
+                .StreamEnd => "Z_STREAM_END",
+                .NeedDict => "Z_NEED_DICT",
+                .ErrNo => "Z_ERRNO",
+                .StreamError => "Z_STREAM_ERROR",
+                .DataError => "Z_DATA_ERROR",
+                .MemError => "Z_MEM_ERROR",
+                .BufError => "Z_BUF_ERROR",
+                .VersionError => "Z_VERSION_ERROR",
+            },
         };
     }
 

test/js/node/test/parallel/test-zlib-from-gzip-with-trailing-garbage.js

@@ -0,0 +1,66 @@
+'use strict';
+// Test unzipping a gzip file that has trailing garbage
+
+const common = require('../common');
+const assert = require('assert');
+const zlib = require('zlib');
+
+// Should ignore trailing null-bytes
+let data = Buffer.concat([
+  zlib.gzipSync('abc'),
+  zlib.gzipSync('def'),
+  Buffer.alloc(10),
+]);
+
+assert.strictEqual(zlib.gunzipSync(data).toString(), 'abcdef');
+
+zlib.gunzip(data, common.mustSucceed((result) => {
+  assert.strictEqual(
+    result.toString(),
+    'abcdef',
+    `result '${result.toString()}' should match original string`
+  );
+}));
+
+// If the trailing garbage happens to look like a gzip header, it should
+// throw an error.
+data = Buffer.concat([
+  zlib.gzipSync('abc'),
+  zlib.gzipSync('def'),
+  Buffer.from([0x1f, 0x8b, 0xff, 0xff]),
+  Buffer.alloc(10),
+]);
+
+assert.throws(
+  () => zlib.gunzipSync(data),
+  /^Error: unknown compression method$/
+);
+
+zlib.gunzip(data, common.mustCall((err, result) => {
+  common.expectsError({
+    code: 'Z_DATA_ERROR',
+    name: 'Error',
+    message: 'unknown compression method'
+  })(err);
+  assert.strictEqual(result, undefined);
+}));
+
+// In this case the trailing junk is too short to be a gzip segment
+// So we ignore it and decompression succeeds.
+data = Buffer.concat([
+  zlib.gzipSync('abc'),
+  zlib.gzipSync('def'),
+  Buffer.from([0x1f, 0x8b, 0xff, 0xff]),
+]);
+
+assert.throws(
+  () => zlib.gunzipSync(data),
+  /^Error: unknown compression method$/
+);
+
+zlib.gunzip(data, common.mustCall((err, result) => {
+  assert(err instanceof Error);
+  assert.strictEqual(err.code, 'Z_DATA_ERROR');
+  assert.strictEqual(err.message, 'unknown compression method');
+  assert.strictEqual(result, undefined);
+}));