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
14 lines
358 B
JavaScript
14 lines
358 B
JavaScript
const {once} = require('./_30s.js');
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test('once is a Function', () => {
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expect(once).toBeInstanceOf(Function);
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});
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test('once returns Function', () => {
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expect(typeof once(x => 10)).toBe('function');
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});
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test('once returns the result only once', () => {
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let onced = once(x => x);
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expect(onced(10)).toBe(10);
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expect(onced(10)).toBe(undefined);
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});
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