Don't alter value of global variables in test. Tests are not isolated…

… from each other

test/specs/core.controller.tests.js

@@ -64,13 +64,7 @@ describe('Chart', function() {
 		});
 
 		it('should initialize config with default options', function() {
-			var callback = function() {};
-
 			var defaults = Chart.defaults;
-			defaults.global.responsiveAnimationDuration = 42;
-			defaults.global.hover.onHover = callback;
-			defaults.line.hover.mode = 'x-axis';
-			defaults.line.spanGaps = true;
 
 			var chart = acquireChart({
 				type: 'line'
@@ -79,18 +73,13 @@ describe('Chart', function() {
 			var options = chart.options;
 			expect(options.defaultFontSize).toBe(defaults.global.defaultFontSize);
 			expect(options.showLines).toBe(defaults.line.showLines);
-			expect(options.spanGaps).toBe(true);
-			expect(options.responsiveAnimationDuration).toBe(42);
-			expect(options.hover.onHover).toBe(callback);
-			expect(options.hover.mode).toBe('x-axis');
+			expect(options.spanGaps).toBe(defaults.line.spanGaps);
+			expect(options.responsiveAnimationDuration).toBe(defaults.global.responsiveAnimationDuration);
+			expect(options.hover.onHover).toBe(defaults.global.hover.onHover);
+			expect(options.hover.mode).toBe(defaults.line.hover.mode);
 		});
 
 		it('should override default options', function() {
-			var defaults = Chart.defaults;
-			defaults.global.responsiveAnimationDuration = 42;
-			defaults.line.hover.mode = 'x-axis';
-			defaults.line.spanGaps = true;
-
 			var chart = acquireChart({
 				type: 'line',
 				options: {