github.com/consensys/gnark@v0.11.0/test/engine_test.go (about)

     1  package test
     2  
     3  import (
     4  	"fmt"
     5  	"math/big"
     6  	"testing"
     7  
     8  	"github.com/consensys/gnark"
     9  	"github.com/consensys/gnark-crypto/ecc"
    10  
    11  	"github.com/consensys/gnark/constraint/solver"
    12  	"github.com/consensys/gnark/frontend"
    13  	"github.com/consensys/gnark/std/math/bits"
    14  )
    15  
    16  type hintCircuit struct {
    17  	A, B frontend.Variable
    18  }
    19  
    20  func (circuit *hintCircuit) Define(api frontend.API) error {
    21  	res, err := api.Compiler().NewHint(bits.GetHints()[0], 1, circuit.A, 3)
    22  	if err != nil {
    23  		return fmt.Errorf("IthBit circuitA 3: %w", err)
    24  	}
    25  	a3b := res[0]
    26  	res, err = api.Compiler().NewHint(bits.GetHints()[0], 1, circuit.A, 25)
    27  	if err != nil {
    28  		return fmt.Errorf("IthBit circuitA 25: %w", err)
    29  	}
    30  	a25b := res[0]
    31  
    32  	res, err = api.Compiler().NewHint(solver.InvZeroHint, 1, circuit.A)
    33  	if err != nil {
    34  		return fmt.Errorf("IsZero CircuitA: %w", err)
    35  	}
    36  	aInvZero := res[0]
    37  
    38  	res, err = api.Compiler().NewHint(solver.InvZeroHint, 1, circuit.B)
    39  	if err != nil {
    40  		return fmt.Errorf("IsZero, CircuitB")
    41  	}
    42  	bInvZero := res[0]
    43  
    44  	// good witness
    45  	expectedA := big.NewInt(8)
    46  	expectedA.ModInverse(expectedA, api.Compiler().Field())
    47  
    48  	api.AssertIsEqual(aInvZero, expectedA)
    49  	api.AssertIsEqual(bInvZero, 0) // b == 0, invZero(b) == 0
    50  	api.AssertIsEqual(a3b, 1)
    51  	api.AssertIsEqual(a25b, 0)
    52  
    53  	return nil
    54  }
    55  
    56  func TestBuiltinHints(t *testing.T) {
    57  	for _, curve := range gnark.Curves() {
    58  		if err := IsSolved(&hintCircuit{}, &hintCircuit{
    59  			A: (0b1000),
    60  			B: (0),
    61  		}, curve.ScalarField()); err != nil {
    62  			t.Fatal(err)
    63  		}
    64  
    65  		if err := IsSolved(&hintCircuit{}, &hintCircuit{
    66  			A: (0b10),
    67  			B: (1),
    68  		}, curve.ScalarField()); err == nil {
    69  			t.Fatal("witness shouldn't solve circuit")
    70  		}
    71  	}
    72  
    73  }
    74  
    75  var isDeferCalled bool
    76  
    77  type EmptyCircuit struct {
    78  	X frontend.Variable
    79  }
    80  
    81  func (c *EmptyCircuit) Define(api frontend.API) error {
    82  	api.AssertIsEqual(c.X, 0)
    83  	api.Compiler().Defer(func(api frontend.API) error {
    84  		isDeferCalled = true
    85  		return nil
    86  	})
    87  	return nil
    88  }
    89  
    90  func TestPreCompileHook(t *testing.T) {
    91  	c := &EmptyCircuit{}
    92  	w := &EmptyCircuit{
    93  		X: 0,
    94  	}
    95  	isDeferCalled = false
    96  	err := IsSolved(c, w, ecc.BN254.ScalarField())
    97  	if err != nil {
    98  		t.Fatal(err)
    99  	}
   100  	if !isDeferCalled {
   101  		t.Error("callback not called")
   102  	}
   103  }