KT-13605 Find Usages fails to find usages of component function defined in Java

#KT-13605 Fixed

idea/idea-analysis/src/org/jetbrains/kotlin/idea/references/referenceUtil.kt

@@ -78,7 +78,7 @@ fun PsiReference.matchesTarget(candidateTarget: PsiElement): Boolean {
             if (candidateTarget !is KtNamedFunction) return false
         }
         is KtDestructuringDeclarationReference -> {
-            if (candidateTarget !is KtNamedFunction && candidateTarget !is KtParameter) return false
+            if (candidateTarget !is KtNamedFunction && candidateTarget !is KtParameter && candidateTarget !is PsiMethod) return false
         }
     }
 

idea/idea-analysis/src/org/jetbrains/kotlin/idea/search/usagesSearch/DestructuringDeclarationReferenceSearcher.kt

@@ -25,24 +25,16 @@ import org.jetbrains.kotlin.KtNodeTypes
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.idea.references.KtDestructuringDeclarationReference
 import org.jetbrains.kotlin.psi.*
-import org.jetbrains.kotlin.resolve.dataClassUtils.getComponentIndex
 import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstance
 
 class DestructuringDeclarationReferenceSearcher(
         targetDeclaration: PsiElement,
+        private val componentIndex: Int,
         searchScope: SearchScope,
         consumer: Processor<PsiReference>,
         optimizer: SearchRequestCollector
 ) : OperatorReferenceSearcher<KtDestructuringDeclaration>(targetDeclaration, searchScope, consumer, optimizer, wordsToSearch = listOf("(")) {
 
-    //TODO
-    private val componentIndex = when (targetDeclaration) {
-        is KtParameter -> targetDeclaration.dataClassComponentFunction()?.name?.asString()?.let { getComponentIndex(it) }
-        is KtFunction -> targetDeclaration.name?.let { getComponentIndex(it) }
-    //TODO: java component functions (see KT-13605)
-        else -> null
-    }
-
     override fun resolveTargetToDescriptor(): FunctionDescriptor? {
         if (targetDeclaration is KtParameter) {
             return targetDeclaration.dataClassComponentFunction()
@@ -52,15 +44,10 @@ class DestructuringDeclarationReferenceSearcher(
         }
     }
 
-    override fun run() {
-        if (componentIndex == null) return
-        super.run()
-    }
-
     override fun extractReference(element: PsiElement): PsiReference? {
         val destructuringDeclaration = element as? KtDestructuringDeclaration ?: return null
         val entries = destructuringDeclaration.entries
-        if (entries.size < componentIndex!!) return null
+        if (entries.size < componentIndex) return null
         return entries[componentIndex - 1].references.firstIsInstance<KtDestructuringDeclarationReference>()
     }
 

idea/idea-analysis/src/org/jetbrains/kotlin/idea/search/usagesSearch/OperatorReferenceSearch.kt

@@ -35,6 +35,7 @@ import org.jetbrains.kotlin.idea.util.fuzzyExtensionReceiverType
 import org.jetbrains.kotlin.idea.util.toFuzzyType
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.resolve.dataClassUtils.getComponentIndex
 import org.jetbrains.kotlin.resolve.dataClassUtils.isComponentLike
 import org.jetbrains.kotlin.resolve.descriptorUtil.isExtension
 import org.jetbrains.kotlin.types.expressions.OperatorConventions
@@ -105,7 +106,8 @@ abstract class OperatorReferenceSearcher<TReferenceElement : KtElement>(
         ): OperatorReferenceSearcher<*>? {
             if (isComponentLike(name)) {
                 if (!options.searchForComponentConventions) return null
-                return DestructuringDeclarationReferenceSearcher(declaration, searchScope, consumer, optimizer)
+                val componentIndex = getComponentIndex(name.asString())
+                return DestructuringDeclarationReferenceSearcher(declaration, componentIndex, searchScope, consumer, optimizer)
             }
 
             if (!options.searchForOperatorConventions) return null
@@ -160,7 +162,7 @@ abstract class OperatorReferenceSearcher<TReferenceElement : KtElement>(
         }  as? FunctionDescriptor
     }
 
-    open fun run() {
+    fun run() {
         val inProgress = SearchesInProgress.get()
         if (!inProgress.add(targetDeclaration)) return //TODO: it's not quite correct
 

idea/testData/findUsages/java/findJavaMethodUsages/javaComponentFunctions.0.java

@@ -0,0 +1,15 @@
+// PSI_ELEMENT: com.intellij.psi.PsiMethod
+// OPTIONS: usages
+
+public class A {
+}
+
+public class JavaClass {
+    public A <caret>component1() {
+        return new A();
+    }
+
+    public int component2() {
+        return 0;
+    }
+}

idea/testData/findUsages/java/findJavaMethodUsages/javaComponentFunctions.0.kt

@@ -0,0 +1,3 @@
+fun f(c: JavaClass) {
+    val (a, n) = c
+}

idea/testData/findUsages/java/findJavaMethodUsages/javaComponentFunctions.log

@@ -0,0 +1,3 @@
+Resolved (a, n)
+Searched references to JavaClass
+Searched references to parameter c of f(c: JavaClass) in Kotlin files

idea/testData/findUsages/java/findJavaMethodUsages/javaComponentFunctions.results.txt

@@ -0,0 +1 @@
+Value read 2 val (a, n) = c

idea/tests/org/jetbrains/kotlin/findUsages/FindUsagesTestGenerated.java

@@ -1569,6 +1569,12 @@ public class FindUsagesTestGenerated extends AbstractFindUsagesTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("javaComponentFunctions.0.java")
+            public void testJavaComponentFunctions() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/findUsages/java/findJavaMethodUsages/javaComponentFunctions.0.java");
+                doTest(fileName);
+            }
+
             @TestMetadata("OverriddenMethodSyntheticAccessor.0.java")
             public void testOverriddenMethodSyntheticAccessor() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("idea/testData/findUsages/java/findJavaMethodUsages/OverriddenMethodSyntheticAccessor.0.java");