/*
* Copyright 2016 Dennis Vriend
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.github.dnvriend.streams.stage.simple
import akka.stream.testkit.scaladsl.TestSink
import com.github.dnvriend.streams.TestSpec
class TakeWhileStageTest extends TestSpec {
/**
* Terminate processing (and cancel the upstream publisher) after predicate
* returns false for the first time. Due to input buffering some elements may have been
* requested from upstream publishers that will then not be processed downstream
* of this step.
*
* The stream will be completed without producing any elements if predicate is false for
* the first stream element.
*
* - Emits when: the predicate is true
* - Backpressures when: downstream backpressures
* - Completes when: predicate returned false or upstream completes
* - Cancels when predicate returned false or downstream cancels
*/
"TakeWhile" should "emit elements while the predicate is true, and completes when the predicate is false" in {
withIterator() { src ⇒
src.takeWhile(_ < 5)
.runWith(TestSink.probe[Int])
.request(Integer.MAX_VALUE)
.expectNext(0, 1, 2, 3, 4)
.expectComplete()
}
}
}
