Implemented LTE, GTE opcode (#260)

* Implemented LTE, GTE opcode

pkg/vm/stack/Int.go

@@ -100,6 +100,20 @@ func (i *Int) Value() *big.Int {
 	return i.val
 }
 
+// Lte returns a bool value from the comparison of two integers, a and b.
+// value is true if a <= b.
+// value is false if a > b.
+func (i *Int) Lte(s *Int) bool {
+	return i.Value().Cmp(s.Value()) != 1
+}
+
+// Gte returns a bool value from the comparison of two integers, a and b.
+// value is true if a >= b.
+// value is false if a < b.
+func (i *Int) Gte(s *Int) bool {
+	return i.Value().Cmp(s.Value()) != -1
+}
+
 // Abs returns a stack integer whose underlying value is
 // the absolute value of the original stack integer.
 func (i *Int) Abs() (*Int, error) {

pkg/vm/vm_ops.go

@@ -10,7 +10,9 @@ var opFunc = map[stack.Instruction]stackInfo{
 	stack.BOOLAND:     BoolAnd,
 	stack.BOOLOR:      BoolOr,
 	stack.LT:          Lt,
+	stack.LTE:         Lte,
 	stack.GT:          Gt,
+	stack.GTE:         Gte,
 	stack.SHR:         Shr,
 	stack.SHL:         Shl,
 	stack.INC:         Inc,

pkg/vm/vm_ops_maths.go

@@ -317,17 +317,36 @@ func Negate(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation,
 	return NONE, nil
 }
 
-func popTwoIntegers(ctx *stack.Context) (*stack.Int, *stack.Int, error) {
-	operandA, err := ctx.Estack.PopInt()
+// Lte pops two integers, a and b, off of the stack and pushes a boolean the stack
+// whose value is true if a's value is less than or equal to b's value.
+// Returns an error if either items cannot be casted to an integer
+func Lte(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
+
+	operandA, operandB, err := popTwoIntegers(ctx)
 	if err != nil {
-		return nil, nil, err
+		return FAULT, err
 	}
-	operandB, err := ctx.Estack.PopInt()
-	if err != nil {
-		return nil, nil, err
+	res := operandB.Lte(operandA)
+
+	ctx.Estack.Push(stack.NewBoolean(res))
+
+	return NONE, nil
 }
 
-	return operandA, operandB, nil
+// Gte pops two integers, a and b, off of the stack and pushes a boolean the stack
+// whose value is true if a's value is greated than or equal to b's value.
+// Returns an error if either items cannot be casted to an integer
+func Gte(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
+
+	operandA, operandB, err := popTwoIntegers(ctx)
+	if err != nil {
+		return FAULT, err
+	}
+	res := operandB.Gte(operandA)
+
+	ctx.Estack.Push(stack.NewBoolean(res))
+
+	return NONE, nil
 }
 
 // Shl pops two integers, a and b, off of the stack and pushes an integer to the stack
@@ -402,6 +421,19 @@ func Gt(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rsta
 	return NONE, nil
 }
 
+func popTwoIntegers(ctx *stack.Context) (*stack.Int, *stack.Int, error) {
+	operandA, err := ctx.Estack.PopInt()
+	if err != nil {
+		return nil, nil, err
+	}
+	operandB, err := ctx.Estack.PopInt()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return operandA, operandB, nil
+}
+
 func popTwoByteArrays(ctx *stack.Context) (*stack.ByteArray, *stack.ByteArray, error) {
 	// Pop first stack item and cast as byte array
 	ba1, err := ctx.Estack.PopByteArray()

pkg/vm/vm_ops_maths_test.go

@@ -385,6 +385,64 @@ func TestNegateOp(t *testing.T) {
 	assert.Equal(t, int64(20), item.Value().Int64())
 }
 
+func TestLteOp(t *testing.T) {
+
+	v := VM{}
+
+	a, err := stack.NewInt(big.NewInt(10))
+	assert.Nil(t, err)
+
+	b, err := stack.NewInt(big.NewInt(10))
+	assert.Nil(t, err)
+
+	ctx := stack.NewContext([]byte{})
+	ctx.Estack.Push(a).Push(b)
+
+	// b is the first item pop.
+	// a is the second item pop.
+	// we perform a <= b and place
+	// the result on top of the evaluation
+	// stack
+	v.executeOp(stack.LTE, ctx)
+
+	// Stack should have one item
+	assert.Equal(t, 1, ctx.Estack.Len())
+
+	item, err := ctx.Estack.PopBoolean()
+	assert.Nil(t, err)
+
+	assert.Equal(t, true, item.Value())
+}
+
+func TestGteOp(t *testing.T) {
+
+	v := VM{}
+
+	a, err := stack.NewInt(big.NewInt(10))
+	assert.Nil(t, err)
+
+	b, err := stack.NewInt(big.NewInt(2))
+	assert.Nil(t, err)
+
+	ctx := stack.NewContext([]byte{})
+	ctx.Estack.Push(a).Push(b)
+
+	// b is the first item pop.
+	// a is the second item pop.
+	// we perform a >= b and place
+	// the result on top of the evaluation
+	// stack
+	v.executeOp(stack.GTE, ctx)
+
+	// Stack should have one item
+	assert.Equal(t, 1, ctx.Estack.Len())
+
+	item, err := ctx.Estack.PopBoolean()
+	assert.Nil(t, err)
+
+	assert.Equal(t, true, item.Value())
+}
+
 func TestShlOp(t *testing.T) {
 
 	v := VM{}
@@ -556,4 +614,3 @@ func TestGtOp(t *testing.T) {
 
 	assert.Equal(t, true, item.Value())
 }
-