fixes #206, add checking for unary ops

lib/runtime/dart/_interceptors.js

 var _interceptors = dart.defineLibrary(_interceptors, {});
 var core = dart.import(core);
 var _internal = dart.import(_internal);
 var _js_helper = dart.lazyImport(_js_helper);
 var collection = dart.import(collection);
 var math = dart.import(math);
 (function(exports, core, _internal, _js_helper, collection, math) {
   'use strict';
   let JSArray$ = dart.generic(function(E) {
     class JSArray extends core.Object {
@@ skipping 416 matching lines @@
   let _shrReceiverPositive = Symbol('_shrReceiverPositive');
   let _shrOtherPositive = Symbol('_shrOtherPositive');
   let _shrBothPositive = Symbol('_shrBothPositive');
   class JSNumber extends Interceptor {
     JSNumber() {
       super.Interceptor();
     }
     compareTo(b) {
       if (!dart.is(b, core.num))
         throw new core.ArgumentError(b);
-      if (this[dartx['<']](b)) {
+      if (dart.notNull(this[dartx['<']](b))) {
         return -1;
-      } else if (this[dartx['>']](b)) {
+      } else if (dart.notNull(this[dartx['>']](b))) {
         return 1;
       } else if (dart.equals(this, b)) {
         if (dart.equals(this, 0)) {
           let bIsNegative = b[dartx.isNegative];
           if (this[dartx.isNegative] == bIsNegative)
             return 0;
-          if (this[dartx.isNegative])
+          if (dart.notNull(this[dartx.isNegative]))
             return -1;
           return 1;
         }
         return 0;
-      } else if (this[dartx.isNaN]) {
-        if (b[dartx.isNaN]) {
+      } else if (dart.notNull(this[dartx.isNaN])) {
+        if (dart.notNull(b[dartx.isNaN])) {
           return 0;
         }
         return 1;
       } else {
         return -1;
       }
     }
     get isNegative() {
       return dart.equals(this, 0) ? (1)[dartx['/']](this) < 0 : this[dartx['<']](0);
     }
     get isNaN() {
       return isNaN(this);
     }
     get isInfinite() {
       return this == Infinity || this == -Infinity;
     }
     get isFinite() {
       return isFinite(this);
     }
     remainder(b) {
       _js_helper.checkNull(b);
       if (!dart.is(b, core.num))
         throw new core.ArgumentError(b);
       return this % b;
     }
     abs() {
       return Math.abs(this);
     }
     get sign() {
-      return this[dartx['>']](0) ? 1 : this[dartx['<']](0) ? -1 : this;
+      return dart.notNull(this[dartx['>']](0)) ? 1 : dart.notNull(this[dartx['<']](0)) ? -1 : this;
     }
     toInt() {
       if (dart.notNull(this[dartx['>=']](JSNumber._MIN_INT32)) && dart.notNull(this[dartx['<=']](JSNumber._MAX_INT32))) {
         return this | 0;
       }
       if (isFinite(this)) {
         return this[dartx.truncateToDouble]() + 0;
       }
       throw new core.UnsupportedError('' + this);
     }
     truncate() {
       return this[dartx.toInt]();
     }
     ceil() {
       return this[dartx.ceilToDouble]()[dartx.toInt]();
     }
     floor() {
       return this[dartx.floorToDouble]()[dartx.toInt]();
     }
     round() {
       return this[dartx.roundToDouble]()[dartx.toInt]();
     }
     ceilToDouble() {
       return Math.ceil(this);
     }
     floorToDouble() {
       return Math.floor(this);
     }
     roundToDouble() {
-      if (this[dartx['<']](0)) {
+      if (dart.notNull(this[dartx['<']](0))) {
         return -Math.round(-this);
       } else {
         return Math.round(this);
       }
     }
     truncateToDouble() {
-      return this[dartx['<']](0) ? this[dartx.ceilToDouble]() : this[dartx.floorToDouble]();
+      return dart.notNull(this[dartx['<']](0)) ? this[dartx.ceilToDouble]() : this[dartx.floorToDouble]();
     }
     clamp(lowerLimit, upperLimit) {
       if (!dart.is(lowerLimit, core.num))
         throw new core.ArgumentError(lowerLimit);
       if (!dart.is(upperLimit, core.num))
         throw new core.ArgumentError(upperLimit);
       if (dart.notNull(lowerLimit[dartx.compareTo](upperLimit)) > 0) {
         throw new core.ArgumentError(lowerLimit);
       }
       if (dart.notNull(this[dartx.compareTo](lowerLimit)) < 0)
         return lowerLimit;
       if (dart.notNull(this[dartx.compareTo](upperLimit)) > 0)
         return upperLimit;
       return this;
     }
     toDouble() {
       return this;
     }
     toStringAsFixed(fractionDigits) {
       _js_helper.checkInt(fractionDigits);
       if (dart.notNull(fractionDigits) < 0 || dart.notNull(fractionDigits) > 20) {
         throw new core.RangeError(fractionDigits);
       }
       let result = this.toFixed(fractionDigits);
-      if (dart.notNull(dart.equals(this, 0)) && dart.notNull(this[dartx.isNegative]))
+      if (dart.equals(this, 0) && dart.notNull(this[dartx.isNegative]))
         return `-${result}`;
       return result;
     }
     toStringAsExponential(fractionDigits) {
       if (fractionDigits === void 0)
         fractionDigits = null;
       let result = null;
       if (fractionDigits != null) {
         _js_helper.checkInt(fractionDigits);
         if (dart.notNull(fractionDigits) < 0 || dart.notNull(fractionDigits) > 20) {
           throw new core.RangeError(fractionDigits);
         }
         result = this.toExponential(fractionDigits);
       } else {
         result = this.toExponential();
       }
-      if (dart.notNull(dart.equals(this, 0)) && dart.notNull(this[dartx.isNegative]))
+      if (dart.equals(this, 0) && dart.notNull(this[dartx.isNegative]))
         return `-${result}`;
       return result;
     }
     toStringAsPrecision(precision) {
       _js_helper.checkInt(precision);
       if (dart.notNull(precision) < 1 || dart.notNull(precision) > 21) {
         throw new core.RangeError(precision);
       }
       let result = this.toPrecision(precision);
-      if (dart.notNull(dart.equals(this, 0)) && dart.notNull(this[dartx.isNegative]))
+      if (dart.equals(this, 0) && dart.notNull(this[dartx.isNegative]))
         return `-${result}`;
       return result;
     }
     toRadixString(radix) {
       _js_helper.checkInt(radix);
       if (dart.notNull(radix) < 2 || dart.notNull(radix) > 36)
         throw new core.RangeError(radix);
       let result = this.toString(radix);
       let rightParenCode = 41;
       if (result[dartx.codeUnitAt](dart.notNull(result.length) - 1) != rightParenCode) {
         return result;
       }
       return JSNumber._handleIEtoString(result);
     }
     static _handleIEtoString(result) {
       let match = /^([\da-z]+)(?:\.([\da-z]+))?\(e\+(\d+)\)$/.exec(result);
       if (match == null) {
         throw new core.UnsupportedError(`Unexpected toString result: ${result}`);
       }
       result = dart.dindex(match, 1);
       let exponent = +dart.dindex(match, 3);
       if (dart.dindex(match, 2) != null) {
         result = result + dart.dindex(match, 2);
         exponent = dart.notNull(exponent) - dart.dindex(match, 2).length;
       }
       return dart.notNull(result) + "0"[dartx['*']](exponent);
     }
     toString() {
-      if (dart.notNull(dart.equals(this, 0)) && 1 / this < 0) {
+      if (dart.equals(this, 0) && 1 / this < 0) {
         return '-0.0';
       } else {
         return "" + this;
       }
     }
     get hashCode() {
       return this & 0x1FFFFFFF;
     }
     ['unary-']() {
       return -this;
@@ skipping 38 matching lines @@
     ['~/'](other) {
       if (false)
         this[_tdivFast](other);
       if (dart.notNull(this[_isInt32](this)) && dart.notNull(this[_isInt32](other)) && 0 != other && -1 != other) {
         return this / other | 0;
       } else {
         return this[_tdivSlow](other);
       }
     }
     [_tdivFast](other) {
-      return this[_isInt32](this) ? this / other | 0 : (this / other)[dartx.toInt]();
+      return dart.notNull(this[_isInt32](this)) ? this / other | 0 : (this / other)[dartx.toInt]();
     }
     [_tdivSlow](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       return (this / other)[dartx.toInt]();
     }
     ['<<'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       if (other < 0)
@@ skipping 124 matching lines @@
       return this[dartx['&']](1) == 1;
     }
     toUnsigned(width) {
       return this[dartx['&']]((1 << dart.notNull(width)) - 1);
     }
     toSigned(width) {
       let signMask = 1 << dart.notNull(width) - 1;
       return dart.notNull(this[dartx['&']](dart.notNull(signMask) - 1)) - dart.notNull(this[dartx['&']](signMask));
     }
     get bitLength() {
-      let nonneg = this[dartx['<']](0) ? dart.notNull(this[dartx['unary-']]()) - 1 : this;
+      let nonneg = dart.notNull(this[dartx['<']](0)) ? dart.notNull(this[dartx['unary-']]()) - 1 : this;
       if (dart.notNull(nonneg) >= 4294967296) {
         nonneg = (dart.notNull(nonneg) / 4294967296).truncate();
         return dart.notNull(JSInt._bitCount(JSInt._spread(nonneg))) + 32;
       }
       return JSInt._bitCount(JSInt._spread(nonneg));
     }
     static _bitCount(i) {
       i = dart.notNull(JSInt._shru(i, 0)) - (dart.notNull(JSInt._shru(i, 1)) & 1431655765);
       i = (dart.notNull(i) & 858993459) + (dart.notNull(JSInt._shru(i, 2)) & 858993459);
       i = 252645135 & dart.notNull(i) + dart.notNull(JSInt._shru(i, 4));
@@ skipping 614 matching lines @@
   exports.JSString = JSString;
   exports.getInterceptor = getInterceptor;
   exports.JSBool = JSBool;
   exports.JSIndexable = JSIndexable;
   exports.JSMutableIndexable = JSMutableIndexable;
   exports.JSObject = JSObject;
   exports.JavaScriptObject = JavaScriptObject;
   exports.PlainJavaScriptObject = PlainJavaScriptObject;
   exports.UnknownJavaScriptObject = UnknownJavaScriptObject;
 })(_interceptors, core, _internal, _js_helper, collection, math);