it('should call the matching pattern function with value when a pattern matches', () => {
const whenMock = createMockFunction().returns('pattern')
expect(pattern().when(String, whenMock)('value')).to.equal('pattern')
expect(whenMock.calls.length).to.equal(1)
expect(whenMock.calls[0].args).to.deep.equal(['value'])
})
it('should call the default function with value when no pattern matches', () => {
const defaultMock = createMockFunction().returns('default')
expect(pattern().default(defaultMock)('value')).to.equal('default')
expect(defaultMock.calls.length).to.equal(1)
expect(defaultMock.calls[0].args).to.deep.equal(['value'])
})
it('should support Array', () => {
const match = pattern()
.when(Array, true)
.default(false)
expect(match([])).to.be.true
expect(match({})).to.be.false
})
it('should not match non-objects', () => {
const match = pattern()
.when({}, true)
.default(false)
expect(match(1)).to.be.false
expect(match(false)).to.be.false
expect(match(null)).to.be.false
})
it('should not match non-arrays', () => {
const match = pattern()
.when([], true)
.default(false)
expect(match({})).to.be.false
expect(match(false)).to.be.false
expect(match(null)).to.be.false
})
it('should support catching all arrays', () => {
const match = pattern()
.when([], true)
.default(false)
expect(match([])).to.be.true
expect(match([1])).to.be.true
expect(match([[], {}])).to.be.true
})
it('should support catching all objects', () => {
const match = pattern()
.when({}, true)
.default(false)
expect(match({})).to.be.true
expect(match([])).to.be.true
expect(match({foo: 'bar'})).to.be.true
})
it('fibonacci', () => {
const fib = pattern()
.when(0, 0)
.when(1, 1)
.default(n => fib(n - 1) + fib(n - 2))
expect(fib(5)).to.equal(5)
expect(fib(8)).to.equal(21)
})
it('should support Number', () => {
const match = pattern()
.when(Number, true)
.default(false)
expect(match(1)).to.be.true
expect(match(0)).to.be.true
expect(match(true)).to.be.false
expect(match(null)).to.be.false
})
it('should pass extra parameters to the default function', () => {
const defaultMock = createMockFunction()
pattern()
.default(defaultMock)
('value', 'extra', 'parameters')
expect(defaultMock.calls.length).to.equal(1)
expect(defaultMock.calls[0].args).to.deep.equal(['value', 'extra', 'parameters'])
})
