Eslint prefer-object-spread (#9466)

* The rule.

* The result

superset-frontend/spec/javascripts/components/AlteredSliceTag_spec.jsx

@@ -116,7 +116,7 @@ describe('AlteredSliceTag', () => {
   let props;
 
   beforeEach(() => {
-    props = Object.assign({}, defaultProps);
+    props = { ...defaultProps };
     wrapper = shallow(<AlteredSliceTag {...props} />);
   });
 
@@ -140,8 +140,8 @@ describe('AlteredSliceTag', () => {
 
   it('sets new diffs when receiving new props', () => {
     const newProps = {
-      currentFormData: Object.assign({}, props.currentFormData),
-      origFormData: Object.assign({}, props.origFormData),
+      currentFormData: { ...props.currentFormData },
+      origFormData: { ...props.origFormData },
     };
     newProps.currentFormData.beta = 10;
     wrapper = shallow(<AlteredSliceTag {...props} />);

superset-frontend/spec/javascripts/components/Checkbox_spec.jsx

@@ -30,7 +30,7 @@ describe('Checkbox', () => {
 
   let wrapper;
   const factory = o => {
-    const props = Object.assign({}, defaultProps, o);
+    const props = { ...defaultProps, ...o };
     return shallow(<Checkbox {...props} />);
   };
   beforeEach(() => {

superset-frontend/spec/javascripts/components/ColumnOption_spec.jsx

@@ -39,7 +39,7 @@ describe('ColumnOption', () => {
   const factory = o => <ColumnOption {...o} />;
   beforeEach(() => {
     wrapper = shallow(factory(defaultProps));
-    props = Object.assign({}, defaultProps);
+    props = { ...defaultProps };
   });
   it('is a valid element', () => {
     expect(React.isValidElement(<ColumnOption {...defaultProps} />)).toBe(true);

superset-frontend/spec/javascripts/components/MetricOption_spec.jsx

@@ -40,7 +40,7 @@ describe('MetricOption', () => {
   const factory = o => <MetricOption {...o} />;
   beforeEach(() => {
     wrapper = shallow(factory(defaultProps));
-    props = Object.assign({}, defaultProps);
+    props = { ...defaultProps };
   });
   it('is a valid element', () => {
     expect(React.isValidElement(<MetricOption {...defaultProps} />)).toBe(true);

superset-frontend/spec/javascripts/components/OnPasteSelect_spec.jsx

@@ -54,9 +54,9 @@ describe('OnPasteSelect', () => {
   let evt;
   let expected;
   beforeEach(() => {
-    props = Object.assign({}, defaultProps);
+    props = { ...defaultProps };
     wrapper = shallow(<OnPasteSelect {...props} />);
-    evt = Object.assign({}, defaultEvt);
+    evt = { ...defaultEvt };
   });
 
   it('renders the supplied selectWrap component', () => {

superset-frontend/spec/javascripts/components/OptionDescription_spec.jsx

@@ -34,7 +34,7 @@ describe('OptionDescription', () => {
   let props;
 
   beforeEach(() => {
-    props = { option: Object.assign({}, defaultProps.option) };
+    props = { option: { ...defaultProps.option } };
     wrapper = shallow(<OptionDescription {...props} />);
   });
 

superset-frontend/spec/javascripts/components/PopoverSection_spec.jsx

@@ -32,7 +32,7 @@ describe('PopoverSection', () => {
 
   let wrapper;
   const factory = overrideProps => {
-    const props = Object.assign({}, defaultProps, overrideProps || {});
+    const props = { ...defaultProps, ...(overrideProps || {}) };
     return shallow(<PopoverSection {...props} />);
   };
   beforeEach(() => {

superset-frontend/spec/javascripts/components/VirtualizedRendererWrap_spec.jsx

@@ -48,7 +48,7 @@ describe('VirtualizedRendererWrap', () => {
   let props;
   beforeEach(() => {
     wrapper = shallow(<RendererWrap {...defaultProps} />);
-    props = Object.assign({}, defaultProps);
+    props = { ...defaultProps };
   });
 
   it('uses the provided renderer', () => {