Add basic tests for vm

pkg/vm/vm_ops.go

@@ -2,11 +2,14 @@ package vm
 
 import "github.com/CityOfZion/neo-go/pkg/vm/stack"
 
-var opFunc = map[stack.Instruction]func(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation) error{
+var opFunc = map[stack.Instruction]func(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation) (Vmstate, error){
 	stack.ADD:         Add,
 	stack.SUB:         Sub,
 	stack.PUSHBYTES1:  PushNBytes,
 	stack.PUSHBYTES75: PushNBytes,
+	stack.RET:         RET,
+	stack.EQUAL:       EQUAL,
+	stack.THROWIFNOT:  THROWIFNOT,
 }
 
 func init() {

pkg/vm/vm_ops_maths_test.go

@@ -24,7 +24,7 @@ func TestAddOp(t *testing.T) {
 	ctx := stack.NewContext([]byte{})
 	ctx.Estack.Push(a).Push(b)
 
-	v.ExecuteOp(stack.ADD, ctx)
+	v.executeOp(stack.ADD, ctx)
 
 	// Stack should have one item
 	assert.Equal(t, 1, ctx.Estack.Len())
@@ -54,7 +54,7 @@ func TestSubOp(t *testing.T) {
 	ctx := stack.NewContext([]byte{})
 	ctx.Estack.Push(a).Push(b)
 
-	v.ExecuteOp(stack.SUB, ctx)
+	v.executeOp(stack.SUB, ctx)
 
 	// Stack should have one item
 	assert.Equal(t, 1, ctx.Estack.Len())

pkg/vm/vm_test.go

@@ -0,0 +1,113 @@
+package vm
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/CityOfZion/neo-go/pkg/vm/stack"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPushAdd(t *testing.T) {
+	builder := stack.NewBuilder()
+
+	// PUSH TWO NUMBER
+	// ADD THEM TOGETHER
+	builder.EmitInt(20).EmitInt(34).EmitOpcode(stack.ADD)
+
+	// Pass program to VM
+	vm := NewVM(builder.Bytes())
+
+	// Execute first OPCODE
+	// Should be PUSH(20)
+	state, err := vm.step()
+	assert.Equal(t, NONE, int(state))
+	assert.Nil(t, err)
+
+	// We should have the number 20 on stack
+	ok := peekTopEStackIsValue(t, vm, 20)
+	assert.True(t, ok)
+
+	// Excute second OPCODE
+	// Should be PUSH(34)
+	state, err = vm.step()
+	assert.Equal(t, NONE, int(state))
+	assert.Nil(t, err)
+
+	// We should have the number 34 at the top of the stack
+	ok = peekTopEStackIsValue(t, vm, 34)
+	assert.True(t, ok)
+
+	// Excute third OPCODE
+	// Should Add both values on the stack
+	state, err = vm.step()
+	assert.Equal(t, NONE, int(state))
+	assert.Nil(t, err)
+
+	// We should now have one value on the stack
+	//It should be equal to 20+34 = 54
+	ok = EstackLen(t, vm, 1)
+	assert.True(t, ok)
+	ok = peekTopEStackIsValue(t, vm, 54)
+	assert.True(t, ok)
+
+	// If we try to step again, we should get an error and HALT
+	// because we have gone over the instruction pointer
+	state, err = vm.step()
+	assert.Equal(t, HALT, int(state))
+	assert.NotNil(t, err)
+
+}
+
+func TestSimpleRun(t *testing.T) {
+
+	// Program pushes 20 and 34 to the stack
+	// Adds them together
+	// pushes 54 to the stack
+	// Checks if result of addition and 54 are equal
+	// Faults if not
+
+	// Push(20)
+	// Push(34)
+	// Add
+	// Push(54)
+	// Equal
+	//THROWIFNOT
+	builder := stack.NewBuilder()
+	builder.EmitInt(20).EmitInt(34).EmitOpcode(stack.ADD)
+	builder.EmitInt(54).EmitOpcode(stack.EQUAL).EmitOpcode(stack.THROWIFNOT)
+	// Pass program to VM
+	vm := NewVM(builder.Bytes())
+
+	_, err := vm.Run()
+	assert.Nil(t, err)
+
+}
+
+// returns true if the value at the top of the evaluation stack is a integer
+// and equals the value passed in
+func peekTopEStackIsValue(t *testing.T, vm *VM, value int64) bool {
+	item := peakTopEstack(t, vm)
+	integer, err := item.Integer()
+	assert.Nil(t, err)
+	return value == integer.Value().Int64()
+}
+
+// peaks the stack item on the top of the evaluation stack
+// if the current context and returns it
+func peakTopEstack(t *testing.T, vm *VM) stack.Item {
+	ctx, err := vm.InvocationStack.CurrentContext()
+	fmt.Println(err)
+	assert.Nil(t, err)
+	item, err := ctx.Estack.Peek(0)
+	assert.Nil(t, err)
+	return item
+}
+
+// returns true if the total number of items on the evaluation stack
+// is equal to value
+func EstackLen(t *testing.T, vm *VM, value int) bool {
+	ctx, err := vm.InvocationStack.CurrentContext()
+	assert.Nil(t, err)
+	return value == ctx.Estack.Len()
+}