83a6a6ea32
* chore: make aware eslint that we use jest By setting up the jest environment, we no longer need to declare the 'test' global in the configuration. * chore: don't need to import expect, it's a jest environment global * chore: don't need to import expect when creating undefined test
12 lines
362 B
JavaScript
12 lines
362 B
JavaScript
const {countBy} = require('./_30s.js');
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test('countBy is a Function', () => {
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expect(countBy).toBeInstanceOf(Function);
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});
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test('Works for functions', () => {
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expect(countBy([6.1, 4.2, 6.3], Math.floor)).toEqual({ 4: 1, 6: 2 });
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});
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test('Works for property names', () => {
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expect(countBy(['one', 'two', 'three'], 'length')).toEqual({ 3: 2, 5: 1 });
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});
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