Improve test_verify_cell_proof_batch()

Author: asn-d6

specs/_features/eip7594/polynomial-commitments-sampling.md

@@ -438,7 +438,10 @@ def verify_cell_proof_batch(row_commitments_bytes: Sequence[Bytes48],
                             cells_bytes: Sequence[Vector[Bytes32, FIELD_ELEMENTS_PER_CELL]],
                             proofs_bytes: Sequence[Bytes48]) -> bool:
     """
-    Check multiple cell proofs. This function implements the naive algorithm of checking every cell
+    Verify a set of cells, given their corresponding proofs and their coordinates (row_id, column_id) in the blob
+    matrix. The list of all commitments is also provided in row_commitments_bytes.
+
+    This function implements the naive algorithm of checking every cell
     individually; an efficient algorithm can be found here:
     https://ethresear.ch/t/a-universal-verification-equation-for-data-availability-sampling/13240
 
@@ -448,6 +451,8 @@ def verify_cell_proof_batch(row_commitments_bytes: Sequence[Bytes48],
 
     Public method.
     """
+    assert len(cells_bytes) == len(proofs_bytes) == len(row_ids) == len(column_ids)
+
     # Get commitments via row IDs
     commitments_bytes = [row_commitments_bytes[row_id] for row_id in row_ids]
 

tests/core/pyspec/eth2spec/test/eip7594/unittests/polynomial_commitments/test_polynomial_commitments.py

@@ -54,15 +54,16 @@ def test_verify_cell_proof_batch(spec):
     blob = get_sample_blob(spec)
     commitment = spec.blob_to_kzg_commitment(blob)
     cells, proofs = spec.compute_cells_and_proofs(blob)
-
     cells_bytes = [[field_element_bytes(element) for element in cell] for cell in cells]
 
+    assert len(cells) == len(proofs)
+
     assert spec.verify_cell_proof_batch(
         row_commitments_bytes=[commitment],
-        row_ids=[0],
-        column_ids=[0, 1],
-        cells_bytes=cells_bytes[0:1],
-        proofs_bytes=proofs,
+        row_ids=[0, 0],
+        column_ids=[0, 4],
+        cells_bytes=[cells_bytes[0], cells_bytes[4]],
+        proofs_bytes=[proofs[0], proofs[4]],
     )