test: use assert.CheckCircuit directly

Until #1422 is resolved

Author: ivokub

std/hash/poseidon2/poseidon2_test.go

@@ -1,29 +1,41 @@
 package poseidon2
 
 import (
-	"github.com/consensys/gnark-crypto/ecc"
 	"testing"
 
+	"github.com/consensys/gnark-crypto/ecc"
 	"github.com/consensys/gnark-crypto/ecc/bls12-377/fr/poseidon2"
 	"github.com/consensys/gnark/frontend"
 	"github.com/consensys/gnark/test"
-	"github.com/stretchr/testify/require"
 )
 
+type Poseidon2Circuit struct {
+	Input    []frontend.Variable
+	Expected frontend.Variable `gnark:",public"`
+}
+
+func (c *Poseidon2Circuit) Define(api frontend.API) error {
+	hsh, err := NewMerkleDamgardHasher(api)
+	if err != nil {
+		return err
+	}
+	hsh.Write(c.Input...)
+	api.AssertIsEqual(hsh.Sum(), c.Expected)
+	return nil
+}
+
 func TestPoseidon2Hash(t *testing.T) {
+	assert := test.NewAssert(t)
+
+	const nbInputs = 5
 	// prepare expected output
 	h := poseidon2.NewMerkleDamgardHasher()
-	for i := range 5 {
+	circInput := make([]frontend.Variable, nbInputs)
+	for i := range nbInputs {
 		_, err := h.Write([]byte{byte(i)})
-		require.NoError(t, err)
+		assert.NoError(err)
+		circInput[i] = i
 	}
 	res := h.Sum(nil)
-
-	test.Function(func(api frontend.API) error {
-		hsh, err := NewMerkleDamgardHasher(api)
-		require.NoError(t, err)
-		hsh.Write(0, 1, 2, 3, 4)
-		api.AssertIsEqual(hsh.Sum(), res)
-		return nil
-	}, test.WithCurves(ecc.BLS12_377))(t)
+	assert.CheckCircuit(&Poseidon2Circuit{Input: make([]frontend.Variable, nbInputs)}, test.WithValidAssignment(&Poseidon2Circuit{Input: circInput, Expected: res}), test.WithCurves(ecc.BLS12_377)) // we have parametrized currently only for BLS12-377
 }