Trouble getting exception type from kotlin throw statement

Permanently deleted user

Created May 12, 2018 13:20

Hello, I have trouble getting an exact class of exception from kotlin KtThrowExpression.

For example test data:

class ThrowRuntimeException {
    fun throws() {
        <caret>throw RuntimeException("")
    }
}

From this, what I expect to extract is java.lang.RuntimeException with this test code:

class ExtractExceptionTest : LightCodeInsightFixtureTestCase() {

 override fun getTestDataPath(): String = "tests"

 fun testExtractRuntimeException() {
 myFixture.configureByFile("ThrowRuntimeException.kt")
 val editor = myFixture.editor
 val psiFile = myFixture.file
 val offset = editor.caretModel.offset
 val element = psiFile.findElementAt(offset)?.parent as KtThrowExpression
 val thrownExpression = element.thrownExpression as KtCallExpression
 val nameExpression = thrownExpression.calleeExpression as KtNameReferenceExpression
 val descriptor = nameExpression.resolveToCall()?.resultingDescriptor
 val declarationDescriptor = descriptor?.containingDeclaration
 val exceptionName = DescriptorUtils.getFqName(declarationDescriptor!!).asString()
 Assert.assertEquals("java.lang.RuntimeException", exceptionName)
 }
}

fun KtElement.resolveToCall(bodyResolveMode: BodyResolveMode = BodyResolveMode.PARTIAL): ResolvedCall<out CallableDescriptor>? =
 getResolvedCall(analyze(bodyResolveMode))

@JvmOverloads
fun KtElement.analyze(bodyResolveMode: BodyResolveMode = BodyResolveMode.FULL): BindingContext =
 getResolutionFacade().analyze(this, bodyResolveMode)

The part that should extract exception is borrowed from kotlin source:

https://github.com/JetBrains/kotlin/blob/e329af093277f2d81a7ecbaa55ad451a0ededa01/idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/IfThenUtils.kt#L82

But in this part

val descriptor = nameExpression.resolveToCall()?.resultingDescriptor

I'm getting a null instead of a resolved descriptor, and do not understand, what is going wrong here

full code with gradle set up: https://www.dropbox.com/s/wb5enebocbebj3z/kotlin-exceptions.zip?dl=0

2 comments

Nikolay Krasko

Created May 17, 2018 12:23

Hello,

The test failure caused by invalid configuration of the dummy project. `LightCodeInsightFixtureTestCase.getProjectDescriptor()` tries to create a project with a mock JDK which is absent in IDEA distribution fetched by org.jetbrains.intellij.gralde plugin.(https://youtrack.jetbrains.com/issue/IJSDK-321)

Here is the possible fix (not very perfomant though, as full JDK is big) :

package some

import com.intellij.openapi.module.Module
import com.intellij.openapi.projectRoots.JavaSdk
import com.intellij.openapi.projectRoots.Sdk
import com.intellij.openapi.projectRoots.impl.JavaSdkImpl
import com.intellij.openapi.roots.ContentEntry
import com.intellij.openapi.roots.LanguageLevelModuleExtension
import com.intellij.openapi.roots.ModifiableRootModel
import com.intellij.pom.java.LanguageLevel
import com.intellij.testFramework.LightProjectDescriptor
import com.intellij.testFramework.fixtures.LightCodeInsightFixtureTestCase
import org.jetbrains.kotlin.idea.references.resolveMainReferenceToDescriptors
import org.jetbrains.kotlin.psi.KtElement
import org.jetbrains.kotlin.psi.psiUtil.parents
import org.jetbrains.kotlin.resolve.DescriptorUtils
import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstance
import org.junit.Assert

class ExtractExceptionTest : LightCodeInsightFixtureTestCase() {

  override fun getTestDataPath(): String = "tests"

  fun testExtractRuntimeException() {
    myFixture.configureByText(
        "Test.kt",
        """
            class ThrowRuntimeException {
                fun throws() {
                    throw <caret>RuntimeException("")
                }
            }
            """.trimIndent()
    )
    val editor = myFixture.editor
    val psiFile = myFixture.file
    val offset = editor.caretModel.offset

    val element = psiFile.findElementAt(offset)!!
    val ktElement = element.parents.firstIsInstance<KtElement>()

    val constructorDescriptor = ktElement.resolveMainReferenceToDescriptors().single()
    val declarationDescriptor = constructorDescriptor.containingDeclaration!!

    val exceptionName = DescriptorUtils.getFqName(declarationDescriptor).asString()
    Assert.assertEquals("java.lang.RuntimeException", exceptionName)
  }

  override fun getProjectDescriptor() = ProjectDescriptorWithFullJDK
}


object ProjectDescriptorWithFullJDK : LightProjectDescriptor() {
  override fun getSdk(): Sdk? {
    return (JavaSdk.getInstance() as JavaSdkImpl).createJdk(
        "JavaHomeJDK",
        System.getenv()["JDK_18"]!!, // Path to JDK on local machine.
        false
    )
  }

  public override fun configureModule(module: Module, model: ModifiableRootModel, contentEntry: ContentEntry) {
    model.getModuleExtension(LanguageLevelModuleExtension::class.java).languageLevel = LanguageLevel.JDK_1_8
  }
}

Permanently deleted user

Created May 21, 2018 05:51

Many thanks, now it working correctly

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