func TestEach(t *testing.T) {
collect := func(items *[]stream.T) stream.EachFn {
return func(data stream.T) {
*items = append(*items, data)
}
}
Convey("Given I have a context", t, func() {
context := rivers.NewContext()
Convey("And a stream of data", func() {
in, out := stream.New(2)
out <- 1
out <- 2
close(out)
Convey("When I apply the transformer to the stream", func() {
var items []stream.T
transformer := transformers.Each(collect(&items))
transformer.Attach(context)
next := transformer.Transform(in)
Convey("Then all items are sent to the next stage", func() {
So(next.ReadAll(), ShouldResemble, []stream.T{1, 2})
Convey("And all items are transformed", func() {
So(items, ShouldResemble, []stream.T{1, 2})
})
})
})
Convey("When I close the context", func() {
context.Close(stream.Done)
Convey("And I apply the transformer to the stream", func() {
var items []stream.T
transformer := transformers.Each(collect(&items))
transformer.Attach(context)
next := transformer.Transform(in)
Convey("Then no item is sent to the next stage", func() {
So(next.ReadAll(), ShouldBeEmpty)
Convey("And no item is transformed", func() {
So(items, ShouldBeEmpty)
})
})
})
})
})
})
}
func (pipeline *Pipeline) Each(fn stream.EachFn) *Pipeline {
return pipeline.ApplyParallel(transformers.Each(fn))
}