How to properly add mockk to android tests? The do...

# mockk

[Marek Kubiczek]

How to properly add mockk to android tests? The documentationsaus the following should suffice

androidTestImplementation "io.mockk:mockk-android:${mockkVersion}"
androidTestImplementation "io.mockk:mockk-agent:${mockkVersion}"

But neither mockk-android nor mock-agent does include dependencies for mockk-jvm that contains all the methods like every, coEvery, verify etc.
So how is it supposed to work?

[Adam S]

hmm, that’s strange. Adding a dependency on mockk-android should automatically bring in the core mockk dependency, because it’s exposed using API https://github.com/mockk/mockk/blob/6587d9bc616111eb3423aa1b9ba4c27f1e3addbf/modules/mockk-android/build.gradle.kts#L21-L25

[Adam S]

what version of MockK/Kotlin/Gradle/Android are you using? There was a change in the MockK layout about 6 months ago, so maybe you’re on an older version of MockK?

[Marek Kubiczek]

I have latest mockk 1.13.4.

[Marek Kubiczek]

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[Marek Kubiczek]

Also the pom file references mockk and not mockk-jvm. But actually mock itself doesn’t have much inside

[Adam S]

mockk vs mockk-jvm is a Kotlin Multiplatform ‘thing’, which is unusual in MockK’s case because everything is JVM. But that shouldn’t concern Gradle users, since Gradle is clever so the -jvm suffix can be dropped

[Adam S]

every, coEvery, verify etc should be inside the MockK file, a couple of files above the one you’ve selected

[Marek Kubiczek]

Apparently gradle is not that clever in my case as it didn’t work for me without the -jvm suffix. I have gradle 8.0 btw.

[Marek Kubiczek]

So now I wonder how does gradle determine which artifact it should pull

[Adam S]

what does “didn’t work for me” look like?

[Adam S]

the -jvm suffix really shouldn’t be necessary, unless you’re using some custom way of fetching dependencies.

I wrote about what -jvm means and how it works under the hood if you want to take a look :) https://stackoverflow.com/q/73914158/4161471

[Marek Kubiczek]

I think it didn’t work the same simply not seeing all the mockk functions. But I will try again.

[Adam S]

👍

[Adam S]

try to check if it’s a problem with IntelliJ vs Gradle, by running ./gradlew check on the command line

[Marek Kubiczek]

So switching back to just mockk without the -jvm didn’t help. The functions still cannot be resolved. And running from command line suffers the same problem

[Adam S]

hmmm interesting

[Adam S]

what’s the error message and/or stacktrace?

[Marek Kubiczek]

It’s basically kind of

file://...CricketRepositoryIntegrationTest.kt:44:35 Unresolved reference: mockk
e: file://...CricketRepositoryIntegrationTest.kt:45:9 Unresolved reference: coEvery
e: file://...CricketRepositoryIntegrationTest.kt:45:19 Unresolved reference: getPopularEvents
e: file://...CricketRepositoryIntegrationTest.kt:45:36 Unresolved reference. None of the following candidates is applicable because of receiver type mismatch:

[Marek Kubiczek]

I think the gradle doesn;t know it should pull the jvm suffixed artifact

[Adam S]

and those files are in src/test/kotlin?

[Adam S]

I’m asking because I think Android has multiple types of test, right? (I’m not an Android dev, so I only have a vague understanding)

[Marek Kubiczek]

these ones actually in src/androidTest/kotlin

[Marek Kubiczek]

but the same problems with unit tests

[Adam S]

can you try using testApi "io.mockk:mockk-android:${mockkVersion}"? I think that testApi should be available

[Adam S]

using testApi is a bit of a shotgun approach, just to try and make sure that MockK is always available as a dependency

[Marek Kubiczek]

Available, but didn’t help

[Adam S]

darn

[Adam S]

how many subprojects do you have?

[Marek Kubiczek]

~30

[Adam S]

how many of them are using Android and/or MockK?

[Marek Kubiczek]

most of them are android ones, part of the android ones are actually using Mockk

[Marek Kubiczek]

hmmm

[Adam S]

hmmm, well I’m not sure what else to suggest. If -jvm works for you, then it works 🤷‍♀️

[Adam S]

the only other thing I noticed this error

e: file://...CricketRepositoryIntegrationTest.kt:45:19 Unresolved reference: getPopularEvents

that’s not a MockK function, so it might indicate some other dependency is missing?

[Marek Kubiczek]

what if… I have a maven proxy, so whenever we pull something from maven is is first cached in our internal server… and what if the modules files are not fetched from the original proxy…

[Adam S]

that sounds unlikely… but not impossible!

[Adam S]

Gradle tends to be pretty good with caching and validating dependencies

[Marek Kubiczek]

I wonder what would happen if this file cannot be seen by gradle https://repo1.maven.org/maven2/io/mockk/mockk/1.13.4/mockk-1.13.4.module

[Marek Kubiczek]

So we were missing these module files on our maven, but still putting them there didn;t help

[Adam S]

ahh okay, yes if you were missing the .module files then you would need the -jvm suffix, because Gradle would have to rely on the Maven POM files which is missing the Gradle metadata

[Marek Kubiczek]

maybe I need to remove local gradle cache then

[Adam S]

I was about to suggest the same!

[Marek Kubiczek]

Thanks for the comprehensive answers 🙏 🍺

[Adam S]

my pleasure! Did you get it working?

[Marek Kubiczek]

Not yet, as I need to put my hands on the proxy server. But verified that it works fine if I use maven central directly. And that the .module files indeed are not queried from the original server and not stored on our proxy.

[Marek Kubiczek]

It also explains some issues we had with conflicting resources coming from META-INF directory. One was from the mock.jar which doesn't contain any classes but still contains some resources while the other one was from the mock-jvm.jar.

[Marek Kubiczek]

Normally when Gradle module metadata is considered the jar from the mock artifact is never downloaded but actually on the fly resolved to mockk-jvm. While when we fell back to POM we were getting both. The mockk.jar coming from transitive dependencies of the mock-android artifact. And the mockk-jvm.jar that we specified explicitly.