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
39 lines
1.0 KiB
JavaScript
39 lines
1.0 KiB
JavaScript
const {head} = require('./_30s.js');
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test('head is a Function', () => {
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expect(head).toBeInstanceOf(Function);
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});
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test('head({ a: 1234}) returns undefined', () => {
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expect(head({ a: 1234 }) === undefined).toBeTruthy();
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});
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test('head([1, 2, 3]) returns 1', () => {
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expect(head([1, 2, 3])).toBe(1);
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});
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test('head({ 0: false}) returns false', () => {
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expect(head({ 0: false })).toBeFalsy();
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});
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test('head(String) returns S', () => {
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expect(head('String')).toBe('S');
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});
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test('head(null) throws an Error', () => {
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expect(() => {
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head(null);
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}).toThrow();
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});
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test('head(undefined) throws an Error', () => {
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expect(() => {
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head(undefined);
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}).toThrow();
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});
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test('head() throws an Error', () => {
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expect(() => {
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head();
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}).toThrow();
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});
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let start = new Date().getTime();
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head([1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 1122, 32124, 23232]);
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let end = new Date().getTime();
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test('head([1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 1122, 32124, 23232]) takes less than 2s to run', () => {
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expect(end - start < 2000).toBeTruthy();
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});
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