No spec vector tests validating `sum()` against official test vectors

There are no tests that validate sum() output against the official multihash test vectors. go-multihash has TestSpecVectors that runs vectors from spec/multihash/tests/values/test_cases.csv.

Problem

The current test suite uses hardcoded test fixtures. There is no automated validation against the official test vectors that cover edge cases, truncation, and all supported hash functions.

go-multihash runs the official vectors:

func TestSpecVectors(t *testing.T) {
    file, _ := os.Open("spec/multihash/tests/values/test_cases.csv")
    // CSV format: algorithm, bits, input, multihash
    for _, testCase := range values[1:] {
        actual, _ := multihash.Sum([]byte(input), code, int(length/8))
        if actual.HexString() != expectedStr {
            t.Fatalf("got the wrong hash")
        }
    }
}

Proposed Solution

1. Add the multihash spec submodule:

   git submodule add https://github.com/multiformats/multihash spec/multihash
   

2. Create test:

   import csv
   import pytest
   from multihash import sum
   
   def test_spec_vectors():
       with open("spec/multihash/tests/values/test_cases.csv") as f:
           reader = csv.reader(f)
           header = next(reader)
           for algorithm, bits_str, input_str, expected_hex in reader:
               length_bits = int(bits_str)
               length_bytes = length_bits // 8
               try:
                   actual = sum(input_str.encode(), algorithm, length=length_bytes)
               except (KeyError, ValueError):
                   pytest.skip(f"Hash {algorithm} not supported")
                   continue
               assert actual.encode("hex").decode() == expected_hex
   

Related

• Go spec vector test: go-multihash spec_test.go TestSpecVectors
• Official vectors: multihash/tests/values/test_cases.csv

Start by reviewing the existing test suite and the proposed multihash spec submodule path, spec/multihash/tests/values/test_cases.csv. Add a test that reads the CSV vectors, invokes sum(), and compares the encoded result while handling unsupported algorithms as described. Run the full test suite; done means the official vectors validate supported hash functions and edge cases.