23 lines
485 B
JavaScript
23 lines
485 B
JavaScript
const expect = require('expect');
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const collatz = require('./collatz.js');
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test('collatz is a Function', () => {
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expect(collatz).toBeInstanceOf(Function);
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});
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test('When n is even, divide by 2', () => {
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expect(collatz(8)).toBe(4);
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});
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test('When n is odd, times by 3 and add 1', () => {
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expect(collatz(9)).toBe(28);
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});
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test('Eventually reaches 1', () => {
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let n = 9;
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while (true) {
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if (n === 1) {
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expect(n).toBe(1);
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break;
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}
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n = collatz(n);
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}
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});
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