Does anyone know how to correctly test a channel ``` corouti

Question

Does anyone know how to correctly test a channel ``` coroutinesTestRule testDispatcher runBlockingTest var latestNav NavEvent = null navChannel consumeEach latestNav = it vm handleAction NearbyListingClicked nearbyListing assertEquals latestNav OpenListing variant listing wmid toString ``` But I m just getting `java lang IllegalStateException This job has not completed yet` The `Channel consumeEach` appears to be blocking which I don t think it should be

streetsofboston · Answer

the `navChannel consumeEach` is not blocking It is likely suspending difference there slightly smiling face I don t see all of the code but if `navChannel` is never closed for sending the `consumeEach` just keeps being suspended

streetsofboston · Answer

You d need to `launch` a coroutine within your test scope and that coroutine should send values to `navChannel` and close it when needed

dan.the.man · Answer

Ah yes that did it thank you but question I m missing something in my understanding

dan.the.man · Answer

``` navChannel consumeEach latestNav = it navChannel close ``` So adding that block doesn t fix it same problem but wrapping it in a `launch` block does fix it which I understand is because the block is now on a different coroutine and not blocking the test

dan.the.man · Answer

But I m not sure why closing it didn t fix that as well

dan.the.man · Answer

It needs both the channel close and to be launched in a separate coroutine I get that it needs to be closed due to the way the test dispatcher works but not why it needs to be launched in a separate one

streetsofboston · Answer

The consumer should not close it The producer or some other manager should I think you are looking to just get one value from the channel Just do `latestNav = navChannel receive `

dan.the.man · Answer

Yup you re right it felt bad closing itself thanks

dan.the.man · Answer

```coroutinesTestRule testDispatcher runBlockingTest val latestEvent = async navChannel receive vm handleAction NearbyListingClicked nearbyListing assertEquals latestEvent await OpenListing variant listing wmid toString ``` Ended up going with this and it s all working as expected thanks