Fix issue with large binary numbers (#43)

src/expression/NumericOperand.test.ts

@@ -1,4 +1,4 @@
-import NumericOperand from './NumericOperand';
+import NumericOperand, { INT_MAX_VALUE } from './NumericOperand';
 
 it('parsed from string', () => {
     var op = NumericOperand.parse('123');
@@ -10,4 +10,17 @@ it('can get other kind', () => {
     var op = new NumericOperand(10, 'dec');
     expect(op.getOtherBase('hex')).toBe('dec');
     expect(op.getOtherBase('bin')).toBe('hex');    
-});
+});
+
+it('negtive value binary string', () => {
+    expect(NumericOperand.toBaseString(-1, 'bin')).toBe('11111111111111111111111111111111');
+});
+
+it('64 bit operand binary string', () => {
+    expect(NumericOperand.toBaseString(68719476735, 'bin')).toBe('111111111111111111111111111111111111');
+});
+
+it('throws on negative 64 bit numbers', () => {
+    var bigN = -(INT_MAX_VALUE+1);
+    expect(() => new NumericOperand(bigN)).toThrowError("BitwiseCmd currently doesn't support 64 bit negative numbers such as " + bigN);
+})

src/expression/NumericOperand.ts

@@ -3,6 +3,10 @@ import { ExpressionInputItem, NumberBase } from './expression-interfaces';
 
 var globalId : number = 1;
 
+const INT_MAX_VALUE = 2147483647;
+
+export {INT_MAX_VALUE};
+
 // Represents numeric value
 export default class NumericOperand implements ExpressionInputItem {
     id: number;
@@ -17,6 +21,9 @@ export default class NumericOperand implements ExpressionInputItem {
         this.base = base || "dec";
         this.lengthInBits = NumericOperand.getBitLength(this.value);
         this.isExpression = false;
+
+        if(value < 0 && !NumericOperand.is32Bit(value))
+            throw new Error("BitwiseCmd currently doesn't support 64 bit negative numbers such as " + value);
     }
             
     getLengthInBits() {
@@ -102,7 +109,10 @@ export default class NumericOperand implements ExpressionInputItem {
                 var hexVal = Math.abs(value).toString(16);
                 return value >= 0 ? '0x' + hexVal : '-0x' + hexVal;
             case 'bin':
-                return (value>>>0).toString(2);
+                // >>> 0 is used to get an actual bit representation of the negative numbers
+                // https://stackoverflow.com/questions/5747123/strange-javascript-operator-expr-0
+                const is32Bit = NumericOperand.is32Bit(value);
+                return (is32Bit && value < 0 ? (value >>> 0) : value).toString(2);
             case 'dec':
                 return value.toString(10);
             default:
@@ -113,4 +123,8 @@ export default class NumericOperand implements ExpressionInputItem {
      static toHexString (hex : string) {
             return hex.indexOf('-') === 0 ? '-0x' + hex.substr(1) : '0x' + hex;
      };
+
+     static is32Bit(n: number) {
+        return Math.abs(n) <= INT_MAX_VALUE
+     }
 }

src/expression/components/BitwiseOperationExpressionView.tsx

@@ -85,8 +85,9 @@ class ExpressionRow extends React.Component<ExpressionRowProps> {
                 </tr>;;
     }
 
-    getBinaryString() : string {            
-        return this.props.expressionItem.evaluate().toBinaryString();
+    getBinaryString() : string {       
+        var binary = this.props.expressionItem.evaluate().toBinaryString();
+        return binary;
     }
 
     getLabel(): string {