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import { inc } from './inc.js'import { isNil } from './isNil.js'import { unless } from './unless.js'
test('happy', () => {  const safeInc = unless(isNil, inc)  expect(safeInc(null)).toBeNull()  expect(safeInc(1)).toBe(2)})
test('curried', () => {  const safeIncCurried = unless(isNil)(inc)  expect(safeIncCurried(null)).toBeNull()})
test('with 3 inputs', () => {  let result = unless(x => x.startsWith('/'), x=> x.concat('/'), '/api')  expect(result).toBe('/api')})