This is a testharness.js-based test.
[FAIL] the unchanged input for 'brotli' should decompress successfully
  promise_test: Unhandled rejection with value: object "TypeError: Failed to construct 'DecompressionStream': Unsupported compression format: 'brotli'"
[FAIL] truncating the input for 'brotli' should give an error
  promise_test: Unhandled rejection with value: object "TypeError: Failed to construct 'DecompressionStream': Unsupported compression format: 'brotli'"
[FAIL] trailing junk for 'brotli' should give an error
  promise_test: Unhandled rejection with value: object "TypeError: Failed to construct 'DecompressionStream': Unsupported compression format: 'brotli'"
Harness: the test ran to completion.