import { describe, it, expect, xit } from '@jest/globals' import { keep, discard } from './strain.ts' describe('strain', () => { it('keeps on empty array returns empty array', () => { const predicate = (_: number): boolean => true expect(keep([], predicate)).toEqual([]) }) xit('keeps everything', () => { const predicate = (_: number): boolean => true expect(keep([1, 3, 5], predicate)).toEqual([1, 3, 5]) }) xit('keeps nothing', () => { const predicate = (_: number): boolean => false expect(keep([1, 3, 5], predicate)).toEqual([]) }) xit('keeps first and last', () => { const predicate = (e: number): boolean => e % 2 === 1 expect(keep([1, 2, 3], predicate)).toEqual([1, 3]) }) xit('keeps neither first nor last', () => { const predicate = (e: number): boolean => e % 2 === 0 expect(keep([1, 2, 3], predicate)).toEqual([2]) }) xit('keeps strings', () => { const words = ['apple', 'zebra', 'banana', 'zombies', 'cherimoya', 'zealot'] const predicate = (word: string): boolean => word.indexOf('z') === 0 const result = keep(words, predicate) expect(result).toEqual(['zebra', 'zombies', 'zealot']) }) xit('keeps arrays', () => { const rows = [ [1, 2, 3], [5, 5, 5], [5, 1, 2], [2, 1, 2], [1, 5, 2], [2, 2, 1], [1, 2, 5], ] const predicate = (row: number[]): boolean => row.indexOf(5) > -1 const result = keep(rows, predicate) expect(result).toEqual([ [5, 5, 5], [5, 1, 2], [1, 5, 2], [1, 2, 5], ]) }) xit('empty discard', () => { const predicate = (_: number): boolean => true expect(discard([], predicate)).toEqual([]) }) xit('discards everything', () => { const predicate = (_: number): boolean => true expect(discard([1, 3, 5], predicate)).toEqual([]) }) it('discards nothing', () => { const predicate = (_: number): boolean => false expect(discard([1, 3, 5], predicate)).toEqual([1, 3, 5]) }) xit('discards first and last', () => { const predicate = (e: number): boolean => e % 2 === 1 expect(discard([1, 2, 3], predicate)).toEqual([2]) }) xit('discards neither first nor last', () => { const predicate = (e: number): boolean => e % 2 === 0 const result = discard([1, 2, 3], predicate) expect(result).toEqual([1, 3]) }) xit('discards strings', () => { const words = ['apple', 'zebra', 'banana', 'zombies', 'cherimoya', 'zealot'] const predicate = (word: string): boolean => word.indexOf('z') === 0 const result = discard(words, predicate) expect(result).toEqual(['apple', 'banana', 'cherimoya']) }) xit('discards arrays', () => { const rows = [ [1, 2, 3], [5, 5, 5], [5, 1, 2], [2, 1, 2], [1, 5, 2], [2, 2, 1], [1, 2, 5], ] const predicate = (row: number[]): boolean => row.indexOf(5) > -1 const result = discard(rows, predicate) expect(result).toEqual([ [1, 2, 3], [2, 1, 2], [2, 2, 1], ]) }) })