How to mock Build.VERSION.SDK_INT using mockk

Question

How can I mock Build.VERSION.SDK_INT in mockk?

I've done the following:

@Test
fun testFoo(){
    mockkStatic(Build::class)
    mockkStatic(Build.VERSION::class)
    every {
        Build.VERSION.SDK_INT
    } answers { 22 }
}

I end up getting io.mockk.MockKException: Missing calls inside every { ... } block. once the code hits the every block.

mocking the API level might lead to inaccurate results - compared to emulating it. — Martin Zeitler, Feb 10 '19 at 08:19

score 10 · Answer 1 · answered Feb 10 '19 at 07:56

10

You can build a wrapper around the Build config like this

object MyAppBuildConfig {
    fun getVersionSDKInt(): Int {
        return Build.VERSION.SDK_INT
    }
}

Then mock the MyAppBuildConfig with mockkObject and return your desire version number

    mockkObject(MyAppBuildConfig)
    every { MyAppBuildConfig.getVersionSDKInt() } returns 22

answered Feb 10 '19 at 07:56

Zakir

1,305
1
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14

This is more a workaround than a solution – Louis Jan 13 '21 at 17:35

HexAndBugs · Answer 2 · 2022-01-07T11:49:26.607

8

I ended up modifying Build.VERSION.SDK_INT using reflection. I added the following helper:

private fun setStaticFieldViaReflection(field: Field, value: Any) {
  field.isAccessible = true
  Field::class.java.getDeclaredField("modifiers").apply {
    isAccessible = true
    setInt(field, field.modifiers and Modifier.FINAL.inv())
  }
  field.set(null, value)
}

and then called it like this in my test:

setStaticFieldViaReflection(Build.VERSION::class.java.getField("SDK_INT"), 23)

edited Jan 07 '22 at 11:49

answered Jan 07 '22 at 11:32

HexAndBugs

5,549
2
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unfortunately this does not seem to work for BuildConfig fields, any idea why? – jteichert Aug 31 '22 at 21:13
I'd guess that the BuildConfig constants are inlined by the compiler because it knows the value at compile time, and that's why it won't work for them. – HexAndBugs Sep 05 '22 at 15:54
On Android use `accessFlags` instead of `modifers`. – Marvin Effing Feb 24 '23 at 14:55

score 0 · Answer 3 · answered Aug 01 '23 at 16:10

0

My answer in another thread https://stackoverflow.com/a/76813421/916826

Need to use a new version of setStaticFieldViaReflection
Add a --add-opens flags

answered Aug 01 '23 at 16:10

Sergei S

2,553
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How to mock Build.VERSION.SDK_INT using mockk

3 Answers3

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