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Imagine I have a `suspend` function that feeds a `StateFlow` with one or two different values, in quick succession. How would I test this with Coroutines 1.6? Issue is that during the test I only see the second emitted value and the first is already gone. I tried different things using different dispatches, but nothing worked out unfortunately.

Hi! You could try collecting the `StateFlow` in an `UnconfinedTestDispatcher`. This will work unless the emissions themselves happen in an unconfined dispatcher.

However, could you share *why* you set `SharedFlow` to two values in quick succession? In production, the first value will typically be lost as well, because `SharedFlow` conflates values. If you rely on both elements being received in production, this is very tricky to actually ensure.

It’s basically a network follows cache-response scenario. The disk is quickly read and emitted, the network call could take up to 20 seconds. In my test of course I don’t have such delays, but still want to see that _both_, the cached and the real value are emitted in proper order.

Hrm… this blocks for 60s and then bails out, dammit, this API: <https://gist.github.com/realdadfish/25cb4d950cec6bfd6f6626cb32af1911>

(This uses FlowTurbine for collecting / asserting)

&gt; In my test of course I don’t have such delays
The recommended solution is to mock the network call with `delay(20.seconds)`. In the test framework, delays are performed using a virtual source of time. So, in fact, the delay will finish instantly, but the test will "think" that 20 seconds passed.

(I used a `CompletableDeferred` solution for this, which did not work)

Many thanks, this worked like a charm! I updated the gist accordingly and made it a bit simpler even: <https://gist.github.com/realdadfish/25cb4d950cec6bfd6f6626cb32af1911>

Turbine makes testing Flows much nicer <https://github.com/cashapp/turbine>