Spy at warnings consistently inside test cases

We move any spies on `console.error()` from `beforeEach()` to the individual `it()` tests. This means that if a new test is introduced in these suites, it does not ignore warnings by default, but fails on any unexpected warning, which is Jest's default behavior.

We also change a few old instances of direct `console.error = jest.genMockFn()` assignment to use `spyOn()` for consistency with the rest of the tests.

src/isomorphic/classic/__tests__/ReactContextValidator-test.js

@@ -31,8 +31,6 @@ describe('ReactContextValidator', function() {
     ReactDOM = require('ReactDOM');
     ReactTestUtils = require('ReactTestUtils');
     reactComponentExpect = require('reactComponentExpect');
-
-    spyOn(console, 'error');
   });
 
   // TODO: This behavior creates a runtime dependency on propTypes. We should
@@ -133,6 +131,8 @@ describe('ReactContextValidator', function() {
   });
 
   it('should check context types', function() {
+    spyOn(console, 'error');
+
     var Component = React.createClass({
       contextTypes: {
         foo: React.PropTypes.string.isRequired,
@@ -202,6 +202,8 @@ describe('ReactContextValidator', function() {
   });
 
   it('should check child context types', function() {
+    spyOn(console, 'error');
+
     var Component = React.createClass({
       childContextTypes: {
         foo: React.PropTypes.string.isRequired,

src/isomorphic/classic/class/__tests__/ReactClass-test.js

@@ -21,7 +21,6 @@ describe('ReactClass-spec', function() {
     React = require('React');
     ReactDOM = require('ReactDOM');
     ReactTestUtils = require('ReactTestUtils');
-    spyOn(console, 'error');
   });
 
   it('should throw when `render` is not specified', function() {
@@ -60,76 +59,62 @@ describe('ReactClass-spec', function() {
   });
 
   it('should warn on invalid prop types', function() {
-    var warn = console.error;
-    console.error = jest.genMockFn();
-    try {
-
-      React.createClass({
-        displayName: 'Component',
-        propTypes: {
-          prop: null,
-        },
-        render: function() {
-          return <span>{this.props.prop}</span>;
-        },
-      });
-      expect(console.error.mock.calls.length).toBe(1);
-      expect(console.error.mock.calls[0][0]).toBe(
-        'Warning: Component: prop type `prop` is invalid; ' +
-        'it must be a function, usually from React.PropTypes.'
-      );
-    } finally {
-      console.error = warn;
-    }
+    spyOn(console, 'error');
+    React.createClass({
+      displayName: 'Component',
+      propTypes: {
+        prop: null,
+      },
+      render: function() {
+        return <span>{this.props.prop}</span>;
+      },
+    });
+    expect(console.error.argsForCall.length).toBe(1);
+    expect(console.error.argsForCall[0][0]).toBe(
+      'Warning: Component: prop type `prop` is invalid; ' +
+      'it must be a function, usually from React.PropTypes.'
+    );
   });
 
   it('should warn on invalid context types', function() {
-    var warn = console.error;
-    console.error = jest.genMockFn();
-    try {
-      React.createClass({
-        displayName: 'Component',
-        contextTypes: {
-          prop: null,
-        },
-        render: function() {
-          return <span>{this.props.prop}</span>;
-        },
-      });
-      expect(console.error.mock.calls.length).toBe(1);
-      expect(console.error.mock.calls[0][0]).toBe(
-        'Warning: Component: context type `prop` is invalid; ' +
-        'it must be a function, usually from React.PropTypes.'
-      );
-    } finally {
-      console.error = warn;
-    }
+    spyOn(console, 'error');
+    React.createClass({
+      displayName: 'Component',
+      contextTypes: {
+        prop: null,
+      },
+      render: function() {
+        return <span>{this.props.prop}</span>;
+      },
+    });
+    expect(console.error.argsForCall.length).toBe(1);
+    expect(console.error.argsForCall[0][0]).toBe(
+      'Warning: Component: context type `prop` is invalid; ' +
+      'it must be a function, usually from React.PropTypes.'
+    );
   });
 
   it('should throw on invalid child context types', function() {
-    var warn = console.error;
-    console.error = jest.genMockFn();
-    try {
-      React.createClass({
-        displayName: 'Component',
-        childContextTypes: {
-          prop: null,
-        },
-        render: function() {
-          return <span>{this.props.prop}</span>;
-        },
-      });
-      expect(console.error.mock.calls.length).toBe(1);
-      expect(console.error.mock.calls[0][0]).toBe(
-        'Warning: Component: child context type `prop` is invalid; ' +
-        'it must be a function, usually from React.PropTypes.'
-      );
-    } finally {
-      console.error = warn;
-    }
+    spyOn(console, 'error');
+    React.createClass({
+      displayName: 'Component',
+      childContextTypes: {
+        prop: null,
+      },
+      render: function() {
+        return <span>{this.props.prop}</span>;
+      },
+    });
+    expect(console.error.argsForCall.length).toBe(1);
+    expect(console.error.argsForCall[0][0]).toBe(
+      'Warning: Component: child context type `prop` is invalid; ' +
+      'it must be a function, usually from React.PropTypes.'
+    );
   });
 
   it('should warn when mispelling shouldComponentUpdate', function() {
+    spyOn(console, 'error');
+
     React.createClass({
       componentShouldUpdate: function() {
         return false;
@@ -163,6 +148,7 @@ describe('ReactClass-spec', function() {
   });
 
   it('should warn when mispelling componentWillReceiveProps', function() {
+    spyOn(console, 'error');
     React.createClass({
       componentWillRecieveProps: function() {
         return false;
@@ -204,6 +190,7 @@ describe('ReactClass-spec', function() {
   // TODO: Consider actually moving these to statics or drop this unit test.
 
   xit('should warn when using deprecated non-static spec keys', function() {
+    spyOn(console, 'error');
     React.createClass({
       mixins: [{}],
       propTypes: {
@@ -348,6 +335,7 @@ describe('ReactClass-spec', function() {
   });
 
   it('should throw when using legacy factories', function() {
+    spyOn(console, 'error');
     var Component = React.createClass({
       render() {
         return <div />;
@@ -355,7 +343,7 @@ describe('ReactClass-spec', function() {
     });
 
     expect(() => Component()).toThrow();
-    expect(console.error.calls.length).toBe(1);
+    expect(console.error.argsForCall.length).toBe(1);
     expect(console.error.argsForCall[0][0]).toBe(
       'Warning: Something is calling a React component directly. Use a ' +
       'factory or JSX instead. See: https://fb.me/react-legacyfactory'

src/isomorphic/classic/types/__tests__/ReactPropTypes-test.js

@@ -241,7 +241,6 @@ describe('ReactPropTypes', function() {
           return <div>{this.props.label}</div>;
         },
       });
-      spyOn(console, 'error');
     });
 
     it('should support components', () => {
@@ -258,6 +257,8 @@ describe('ReactPropTypes', function() {
     });
 
     it('should be able to define a single child as label', () => {
+      spyOn(console, 'error');
+
       var instance = <Component label={<div />} />;
       instance = ReactTestUtils.renderIntoDocument(instance);
 
@@ -265,6 +266,8 @@ describe('ReactPropTypes', function() {
     });
 
     it('should warn when passing no label and isRequired is set', () => {
+      spyOn(console, 'error');
+
       var instance = <Component />;
       instance = ReactTestUtils.renderIntoDocument(instance);
 
@@ -782,7 +785,6 @@ describe('ReactPropTypes', function() {
   describe('Custom validator', function() {
     beforeEach(function() {
       jest.resetModuleRegistry();
-      spyOn(console, 'error');
     });
 
     it('should have been called with the right params', function() {
@@ -820,6 +822,8 @@ describe('ReactPropTypes', function() {
     });
 
     it('should have received the validator\'s return value', function() {
+      spyOn(console, 'error');
+
       var spy = jasmine.createSpy().andCallFake(
         function(props, propName, componentName) {
           if (props[propName] !== 5) {
@@ -845,6 +849,8 @@ describe('ReactPropTypes', function() {
 
     it('should not warn if the validator returned null',
       function() {
+        spyOn(console, 'error');
+
         var spy = jasmine.createSpy().andCallFake(
           function(props, propName, componentName) {
             return null;

src/renderers/shared/reconciler/__tests__/ReactCompositeComponent-test.js

@@ -68,8 +68,6 @@ describe('ReactCompositeComponent', function() {
           <b></b>;
       },
     });
-
-    spyOn(console, 'error');
   });
 
   it('should support module pattern components', function() {
@@ -123,7 +121,6 @@ describe('ReactCompositeComponent', function() {
     container.innerHTML = markup;
 
     ReactDOM.render(<Parent />, container);
-    expect(console.error).not.toHaveBeenCalled();
   });
 
   it('should react to state changes from callbacks', function() {
@@ -173,6 +170,8 @@ describe('ReactCompositeComponent', function() {
   });
 
   it('should auto bind methods and values correctly', function() {
+    spyOn(console, 'error');
+
     var ComponentClass = React.createClass({
       getInitialState: function() {
         return {valueToReturn: 'hi'};
@@ -273,6 +272,8 @@ describe('ReactCompositeComponent', function() {
   });
 
   it('should warn about `forceUpdate` on unmounted components', function() {
+    spyOn(console, 'error');
+
     var container = document.createElement('div');
     document.body.appendChild(container);
 
@@ -303,6 +304,8 @@ describe('ReactCompositeComponent', function() {
   });
 
   it('should warn about `setState` on unmounted components', function() {
+    spyOn(console, 'error');
+
     var container = document.createElement('div');
     document.body.appendChild(container);
 
@@ -367,17 +370,16 @@ describe('ReactCompositeComponent', function() {
     });
 
     var instance = ReactDOM.render(<Component />, container);
-
     instance.setState({value: 1});
-    expect(console.error.calls.length).toBe(0);
 
     ReactDOM.unmountComponentAtNode(container);
-    expect(console.error.calls.length).toBe(0);
     expect(cbCalled).toBe(false);
   });
 
 
   it('should warn about `setState` in render', function() {
+    spyOn(console, 'error');
+
     var container = document.createElement('div');
 
     var renderedState = -1;
@@ -425,6 +427,8 @@ describe('ReactCompositeComponent', function() {
   });
 
   it('should warn about `setState` in getChildContext', function() {
+    spyOn(console, 'error');
+
     var container = document.createElement('div');
 
     var renderPasses = 0;
@@ -499,6 +503,8 @@ describe('ReactCompositeComponent', function() {
   });
 
   it('should warn when shouldComponentUpdate() returns undefined', function() {
+    spyOn(console, 'error');
+
     var Component = React.createClass({
       getInitialState: function() {
         return {bogus: false};
@@ -524,6 +530,8 @@ describe('ReactCompositeComponent', function() {
   });
 
   it('should warn when componentDidUnmount method is defined', function() {
+    spyOn(console, 'error');
+
     var Component = React.createClass({
       componentDidUnmount: function() {
       },
@@ -659,8 +667,6 @@ describe('ReactCompositeComponent', function() {
     parentInstance.setState({flag: true});
     expect(parentInstance.state.flag).toBe(true);
 
-    expect(console.error.argsForCall.length).toBe(0);
-
     reactComponentExpect(childInstance).scalarContextEqual({foo: 'bar', flag: true});
   });
 
@@ -719,8 +725,6 @@ describe('ReactCompositeComponent', function() {
     // We update <Parent /> while <Child /> is still a static prop relative to this update
     wrapper.refs.parent.setState({flag: false});
 
-    expect(console.error.argsForCall.length).toBe(0);
-
     expect(wrapper.refs.parent.state.flag).toEqual(false);
     reactComponentExpect(wrapper.refs.child).scalarContextEqual({flag: false});
 
@@ -840,8 +844,6 @@ describe('ReactCompositeComponent', function() {
     });
     expect(parentInstance.state.flag).toBe(true);
 
-    expect(console.error.argsForCall.length).toBe(0);
-
     reactComponentExpect(childInstance).scalarContextEqual({foo: 'bar', depth: 0});
   });
 
@@ -1036,6 +1038,8 @@ describe('ReactCompositeComponent', function() {
   });
 
   it('should disallow nested render calls', function() {
+    spyOn(console, 'error');
+
     var Inner = React.createClass({
       render: function() {
         return <div />;
@@ -1176,8 +1180,6 @@ describe('ReactCompositeComponent', function() {
 
     var div = document.createElement('div');
     ReactDOM.render(<Parent><Component /></Parent>, div);
-
-    expect(console.error.argsForCall.length).toBe(0);
   });
 
   it('should replace state', function() {
@@ -1270,15 +1272,11 @@ describe('ReactCompositeComponent', function() {
     });
 
     ReactDOM.render(<Outer><Component /></Outer>, container);
-
-    expect(console.error.calls.length).toBe(0);
-
     ReactDOM.render(<Outer />, container);
-
-    expect(console.error.calls.length).toBe(0);
   });
 
   it('should warn when mutated props are passed', function() {
+    spyOn(console, 'error');
 
     var container = document.createElement('div');