Compilation error is not thrown from KSPLogger logging error in 1.6.10-1.0.3

[seankim-android]

I have a SymbolProcessor which was throwing a KotlinCompilation.ExitCode.Compilation.ExitCode.COMPILATION_ERROR from environment.logger.error() as expected in 1.0.2. I have some unit tests to catch the error, which is now failing with 1.0.3 because it returns KotlinCompilation.ExitCode.Compilation.ExitCode.OK, and the KSPLogger API doesn't fail the compilation.

Is this intended? If so, is there a more preferred way to fail the compilation?

[ting-yuan]

Yes it is. It is changed from returning COMPILATION_ERROR to OK to workaround this issue:
https://youtrack.jetbrains.com/issue/KT-30172

All callers to the AnalysisHandlerExtension compiler plugin (KSP is one of them) in the compiler handle errors by checking error logs. Therefore in Gradle and command line users shouldn't notice the difference.

This reminds me that there can be issues when running from kotlin-compile-testing, for example 😢 May I know how you run KSP?

[ting-yuan]

btw, the upstream fix to KT-30172 is here: JetBrains/kotlin#3950

We'll roll back to return COMPILATION_ERROR once it is merged.

[ZacSweers]

We run it via kotlin-compile-testing in unit tests

[seankim-android]

Adding some sample code snippet

Sample SymbolProcessorProvider

@AutoService(SymbolProcessorProvider::class)
class MySymbolProcessorProvider : SymbolProcessorProvider {
  override fun create(environment: SymbolProcessorEnvironment): SymbolProcessor {
    return object : SymbolProcessor {
      override fun process(resolver: Resolver): List<KSAnnotated> {
        environment.logger.error("throw an error")
        return emptyList()
      }
    }
  }
}

Sample test

@Test
fun `Compilation fails with KSPLogger error`() {
  val compilation = newCompilation(
    """
      package example.test

      interface SomeClass
      """
  )
  val result = compilation.compile()
  Truth.assertThat(result.exitCode).isEqualTo(KotlinCompilation.ExitCode.COMPILATION_ERROR)
}

Output from the test in 1.0.2

e: Error occurred in KSP, check log for detail
e: [ksp] throw an error

Test passed

Output from the test in 1.0.3

e: Error occurred in KSP, check log for detail
e: [ksp] throw an error

expected: COMPILATION_ERROR
but was : OK
expected: COMPILATION_ERROR
but was : OK
	at app//slack.guinness.compiler.MySymbolProcessorTest.Compilation fails with KSPLogger error(MySymbolProcessorTest.kt:25)

[seankim-android]

Thanks @ting-yuan for your response! Is there a workaround for raising the COMPILATION_ERROR with ksp for the example test case provided above, or do we have wait for the upstream fix for this? I'm trying to see if there is another way to fail compilation without changing the unit test.

[ting-yuan]

Here is a patch to KCT to partially fix this problem: Unfortunately INTERNAL_ERROR is no longer possible; Any previous INTERNAL_ERROR in KSP becomes COMPILATION_ERROR until the fix lands in Kotlin compiler and KSP switches back.

I cannot think of any workaround in processors or outside of kotlin-compile-testing, because KSP always returns OK. It returns OK even when processor throws an exception.

[ting-yuan]

Fixed in another way in #865.