[refactor] Migrate from Mocha+Chai to Jest (#6079)

* [refactor] Migrate from Mocha+Chai to Jest

This change migrates all the existing unit tests
- to Jest's global expect and matchers from chai's imported expect, asserts and matchers.
- to Jest's describe/test from mocha's describe/it

The majority of the mechanical changes to tests are achieved through running jest-codemods. The only two note-worthy manual tweaks:
1. Setting a testURL of http://localhost in jest config and adjusting a few tests to leverage this value instead of relying on about:blank.
2. Re-enabling ExploreChartPanel_spec which was previously commented out as we cannot have empty tests with nothing in it with Jest. :)

This change also removes dependencies to Mocha and Chai.

* Remove the test:one command as it now does the same thing as test.

* Fixing lint errors. The diff looks large but is large done through `yarn run lint --fix`

The only noteworthy change is the one in eslintrc for tests. The env has been updated from mocha to jest.

* Adding eslint-plugin-jest and further modify tests.

- One small fix in sqllab's Timer Spec for a test that is not using the spy it created for testing.
- Deletion of a duplicated test caught by eslint-plugin-jest.

* - Make istanbul coverage work with Jest.

- Remove dependency on stand-alone istanbul and babel-istanbul as they're built-into jest. Yes!

* Attempt to fix dynamic imports in tests.

* run sequentially and log heap usage

* - tweaking maxworkers for travis and specifying coverageDirectory for codecov

- remove dynamic import in shim.js now that it is set in babelrc for tests only.

superset/assets/spec/javascripts/visualizations/models/ChartPlugin_spec.js

@@ -1,5 +1,3 @@
-import { describe, it } from 'mocha';
-import { expect } from 'chai';
 import ChartPlugin from '../../../../src/visualizations/core/models/ChartPlugin';
 import ChartMetadata from '../../../../src/visualizations/core/models/ChartMetadata';
 
@@ -7,7 +5,7 @@ describe('ChartPlugin', () => {
   const metadata = new ChartMetadata({});
 
   it('exists', () => {
-    expect(ChartPlugin).to.not.equal(undefined);
+    expect(ChartPlugin).toBeDefined();
   });
 
   describe('new ChartPlugin()', () => {
@@ -16,13 +14,13 @@ describe('ChartPlugin', () => {
         metadata,
         Chart() {},
       });
-      expect(plugin).to.be.instanceof(ChartPlugin);
+      expect(plugin).toBeInstanceOf(ChartPlugin);
     });
     it('throws an error if metadata is not specified', () => {
-      expect(() => new ChartPlugin()).to.throw(Error);
+      expect(() => new ChartPlugin()).toThrowError(Error);
     });
     it('throws an error if none of Chart or loadChart is specified', () => {
-      expect(() => new ChartPlugin({ metadata })).to.throw(Error);
+      expect(() => new ChartPlugin({ metadata })).toThrowError(Error);
     });
   });
 
@@ -32,11 +30,11 @@ describe('ChartPlugin', () => {
       Chart() {},
     });
     it('throws an error if key is not provided', () => {
-      expect(() => plugin.register()).to.throw(Error);
-      expect(() => plugin.configure({ key: 'abc' }).register()).to.not.throw(Error);
+      expect(() => plugin.register()).toThrowError(Error);
+      expect(() => plugin.configure({ key: 'abc' }).register()).not.toThrowError(Error);
     });
     it('returns itself', () => {
-      expect(plugin.configure({ key: 'abc' }).register()).to.equal(plugin);
+      expect(plugin.configure({ key: 'abc' }).register()).toBe(plugin);
     });
   });
 });

superset/assets/spec/javascripts/visualizations/models/Plugin_spec.js

@@ -1,35 +1,39 @@
-import { describe, it } from 'mocha';
-import { expect } from 'chai';
 import Plugin from '../../../../src/visualizations/core/models/Plugin';
 
 describe('Plugin', () => {
   it('exists', () => {
-    expect(Plugin).to.not.equal(undefined);
+    expect(Plugin).toBeDefined();
   });
 
   describe('new Plugin()', () => {
     it('creates a new plugin', () => {
       const plugin = new Plugin();
-      expect(plugin).to.be.instanceof(Plugin);
+      expect(plugin).toBeInstanceOf(Plugin);
     });
   });
 
   describe('.configure(config, replace)', () => {
-    it('extends the default config with given config when replace is not set or false', () => {
-      const plugin = new Plugin();
-      plugin.configure({ key: 'abc', foo: 'bar' });
-      plugin.configure({ key: 'def' });
-      expect(plugin.config).to.deep.equal({ key: 'def', foo: 'bar' });
-    });
-    it('replaces the default config with given config when replace is true', () => {
-      const plugin = new Plugin();
-      plugin.configure({ key: 'abc', foo: 'bar' });
-      plugin.configure({ key: 'def' }, true);
-      expect(plugin.config).to.deep.equal({ key: 'def' });
-    });
+    it(
+      'extends the default config with given config when replace is not set or false',
+      () => {
+        const plugin = new Plugin();
+        plugin.configure({ key: 'abc', foo: 'bar' });
+        plugin.configure({ key: 'def' });
+        expect(plugin.config).toEqual({ key: 'def', foo: 'bar' });
+      },
+    );
+    it(
+      'replaces the default config with given config when replace is true',
+      () => {
+        const plugin = new Plugin();
+        plugin.configure({ key: 'abc', foo: 'bar' });
+        plugin.configure({ key: 'def' }, true);
+        expect(plugin.config).toEqual({ key: 'def' });
+      },
+    );
     it('returns the plugin itself', () => {
       const plugin = new Plugin();
-      expect(plugin.configure({ key: 'abc' })).to.equal(plugin);
+      expect(plugin.configure({ key: 'abc' })).toBe(plugin);
     });
   });
 
@@ -38,11 +42,11 @@ describe('Plugin', () => {
       const plugin = new Plugin();
       plugin.configure({ key: 'abc', foo: 'bar' });
       plugin.resetConfig();
-      expect(plugin.config).to.deep.equal({});
+      expect(plugin.config).toEqual({});
     });
     it('returns the plugin itself', () => {
       const plugin = new Plugin();
-      expect(plugin.resetConfig()).to.equal(plugin);
+      expect(plugin.resetConfig()).toBe(plugin);
     });
   });
 });

superset/assets/spec/javascripts/visualizations/models/Preset_spec.js

@@ -1,17 +1,15 @@
-import { describe, it } from 'mocha';
-import { expect } from 'chai';
 import Preset from '../../../../src/visualizations/core/models/Preset';
 import Plugin from '../../../../src/visualizations/core/models/Plugin';
 
 describe('Preset', () => {
   it('exists', () => {
-    expect(Preset).to.not.equal(undefined);
+    expect(Preset).toBeDefined();
   });
 
   describe('new Preset()', () => {
     it('creates new preset', () => {
       const preset = new Preset();
-      expect(preset).to.be.instanceOf(Preset);
+      expect(preset).toBeInstanceOf(Preset);
     });
   });
 
@@ -54,12 +52,12 @@ describe('Preset', () => {
         ],
       });
       preset3.register();
-      expect(values).to.deep.equal([1, 2, 3, 'abc']);
+      expect(values).toEqual([1, 2, 3, 'abc']);
     });
 
     it('returns itself', () => {
       const preset = new Preset();
-      expect(preset.register()).to.equal(preset);
+      expect(preset.register()).toBe(preset);
     });
   });
 });

superset/assets/spec/javascripts/visualizations/nvd3/utils_spec.js

@@ -1,5 +1,3 @@
-import { expect } from 'chai';
-
 import { formatLabel, tryNumify } from '../../../../src/visualizations/nvd3/utils';
 
 describe('nvd3/utils', () => {
@@ -9,27 +7,27 @@ describe('nvd3/utils', () => {
   };
   describe('formatLabel()', () => {
     it('formats simple labels', () => {
-      expect(formatLabel('foo')).to.equal('foo');
-      expect(formatLabel(['foo'])).to.equal('foo');
-      expect(formatLabel(['foo', 'bar'])).to.equal('foo, bar');
+      expect(formatLabel('foo')).toBe('foo');
+      expect(formatLabel(['foo'])).toBe('foo');
+      expect(formatLabel(['foo', 'bar'])).toBe('foo, bar');
     });
     it('formats simple labels with lookups', () => {
-      expect(formatLabel('foo', verboseMap)).to.equal('Foo');
-      expect(formatLabel('baz', verboseMap)).to.equal('baz');
-      expect(formatLabel(['foo'], verboseMap)).to.equal('Foo');
-      expect(formatLabel(['foo', 'bar', 'baz'], verboseMap)).to.equal('Foo, Bar, baz');
+      expect(formatLabel('foo', verboseMap)).toBe('Foo');
+      expect(formatLabel('baz', verboseMap)).toBe('baz');
+      expect(formatLabel(['foo'], verboseMap)).toBe('Foo');
+      expect(formatLabel(['foo', 'bar', 'baz'], verboseMap)).toBe('Foo, Bar, baz');
     });
     it('deals with time shift properly', () => {
-      expect(formatLabel(['foo', '1 hour offset'], verboseMap)).to.equal('Foo, 1 hour offset');
-      expect(formatLabel(['foo', 'bar', 'baz', '2 hours offset'], verboseMap)).to.equal('Foo, Bar, baz, 2 hours offset');
+      expect(formatLabel(['foo', '1 hour offset'], verboseMap)).toBe('Foo, 1 hour offset');
+      expect(formatLabel(['foo', 'bar', 'baz', '2 hours offset'], verboseMap)).toBe('Foo, Bar, baz, 2 hours offset');
     });
   });
   describe('tryNumify()', () => {
     it('tryNumify works as expected', () => {
-      expect(tryNumify(5)).to.equal(5);
-      expect(tryNumify('5')).to.equal(5);
-      expect(tryNumify('5.1')).to.equal(5.1);
-      expect(tryNumify('a string')).to.equal('a string');
+      expect(tryNumify(5)).toBe(5);
+      expect(tryNumify('5')).toBe(5);
+      expect(tryNumify('5.1')).toBe(5.1);
+      expect(tryNumify('a string')).toBe('a string');
     });
   });
 });

superset/assets/spec/javascripts/visualizations/table_spec.jsx

@@ -1,4 +1,3 @@
-import { expect } from 'chai';
 import $ from 'jquery';
 import '../../helpers/shim';
 import tableVis from '../../../src/visualizations/Table/adaptor';
@@ -33,24 +32,24 @@ describe('table viz', () => {
   it('renders into a container', () => {
     $('body').html(div);
     const container = $(baseSlice.selector);
-    expect(container.length).to.equal(1);
+    expect(container).toHaveLength(1);
   });
 
   it('renders header and body datatables in container', () => {
     $('body').html(div);
     const container = $(baseSlice.selector);
 
-    expect(container.find('.dataTable').length).to.equal(0);
+    expect(container.find('.dataTable')).toHaveLength(0);
     tableVis(baseSlice, basePayload);
-    expect(container.find('.dataTable').length).to.equal(2);
+    expect(container.find('.dataTable')).toHaveLength(2);
 
     const tableHeader = container.find('.dataTable')[0];
-    expect($(tableHeader).find('thead tr').length).to.equal(1);
-    expect($(tableHeader).find('th').length).to.equal(2);
+    expect($(tableHeader).find('thead tr')).toHaveLength(1);
+    expect($(tableHeader).find('th')).toHaveLength(2);
 
     const tableBody = container.find('.dataTable')[1];
-    expect($(tableBody).find('tbody tr').length).to.equal(2);
-    expect($(tableBody).find('th').length).to.equal(2);
+    expect($(tableBody).find('tbody tr')).toHaveLength(2);
+    expect($(tableBody).find('th')).toHaveLength(2);
   });
 
   it('hides the sort by column', () => {
@@ -74,7 +73,7 @@ describe('table viz', () => {
 
     const container = $(slice.selector);
     const tableHeader = container.find('.dataTable')[0];
-    expect($(tableHeader).find('th').length).to.equal(2);
+    expect($(tableHeader).find('th')).toHaveLength(2);
   });
 
   it('works with empty list for sort by', () => {
@@ -96,6 +95,6 @@ describe('table viz', () => {
 
     const container = $(slice.selector);
     const tableBody = container.find('.dataTable')[1];
-    expect($(tableBody).find('th').length).to.equal(3);
+    expect($(tableBody).find('th')).toHaveLength(3);
   });
 });