RxLua/tests/takeWhile.lua
2016-10-15 10:31:23 -07:00

31 lines
1.2 KiB
Lua

describe('takeWhile', function()
it('produces an error if its parent errors', function()
local observable = Rx.Observable.of(''):map(function(x) return x() end)
expect(observable.subscribe).to.fail()
expect(observable:takeWhile(function() end).subscribe).to.fail()
end)
it('uses the identity function if no predicate is specified', function()
local observable = Rx.Observable.fromTable({true, true, false}):takeWhile()
expect(observable).to.produce(true, true)
end)
it('stops producing values once the predicate returns false', function()
local function isEven(x) return x % 2 == 0 end
local observable = Rx.Observable.fromTable({2, 3, 4}, ipairs):takeWhile(isEven)
expect(observable).to.produce(2)
end)
it('produces no values if the predicate never returns true', function()
local function isEven(x) return x % 2 == 0 end
local observable = Rx.Observable.fromTable({1, 3, 5}):takeWhile(isEven)
expect(observable).to.produce.nothing()
end)
it('calls onError if the predicate errors', function()
local onError = spy()
Rx.Observable.fromRange(3):takeWhile(error):subscribe(nil, onError, nil)
expect(#onError).to.equal(1)
end)
end)