Fix "Unused import" for 'provideDelegate'

#KT-31319 Fixed

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

@@ -37,9 +37,9 @@ class KtPropertyDelegationMethodsReference(element: KtPropertyDelegate) : KtMult
 
     override fun getTargetDescriptors(context: BindingContext): Collection<DeclarationDescriptor> {
         val property = expression.getStrictParentOfType<KtProperty>() ?: return emptyList()
-        val descriptor = context[BindingContext.DECLARATION_TO_DESCRIPTOR, property] as? VariableDescriptorWithAccessors ?: return emptyList()
+        val descriptor = context[BindingContext.DECLARATION_TO_DESCRIPTOR, property] as? VariableDescriptorWithAccessors
-        return (descriptor.accessors.mapNotNull {
+            ?: return emptyList()
-            accessor ->
+        return (descriptor.accessors.mapNotNull { accessor ->
             context.get(BindingContext.DELEGATED_PROPERTY_RESOLVED_CALL, accessor)?.candidateDescriptor
         } + listOfNotNull(context.get(BindingContext.PROVIDE_DELEGATE_RESOLVED_CALL, descriptor)?.candidateDescriptor))
     }
@@ -47,6 +47,10 @@ class KtPropertyDelegationMethodsReference(element: KtPropertyDelegate) : KtMult
     override val resolvesByNames: Collection<Name> get() = NAMES
 
     companion object {
-        private val NAMES = listOf(OperatorNameConventions.GET_VALUE, OperatorNameConventions.SET_VALUE)
+        private val NAMES = listOf(
+            OperatorNameConventions.GET_VALUE,
+            OperatorNameConventions.SET_VALUE,
+            OperatorNameConventions.PROVIDE_DELEGATE
+        )
     }
 }

idea/testData/editor/optimizeImports/common/ProvideDelegate.dependency.kt

@@ -0,0 +1,7 @@
+package a
+
+import kotlin.properties.ReadOnlyProperty
+import kotlin.reflect.KProperty
+
+class C
+operator fun C.provideDelegate(thisRef: Any, prop: KProperty<*>): ReadOnlyProperty<Any, C> = TODO()

idea/testData/editor/optimizeImports/common/ProvideDelegate.kt

@@ -0,0 +1,8 @@
+package b
+
+import a.C
+import a.provideDelegate
+
+class Example {
+    val c: C = C()
+}

idea/testData/editor/optimizeImports/common/ProvideDelegate.kt.after

@@ -0,0 +1,7 @@
+package b
+
+import a.C
+
+class Example {
+    val c: C = C()
+}

idea/testData/editor/optimizeImports/common/ProvideDelegate2.dependency.kt

@@ -0,0 +1,7 @@
+package a
+
+import kotlin.properties.ReadOnlyProperty
+import kotlin.reflect.KProperty
+
+class C
+operator fun C.provideDelegate(thisRef: Any, prop: KProperty<*>): ReadOnlyProperty<Any, C> = TODO()

idea/testData/editor/optimizeImports/common/ProvideDelegate2.kt

@@ -0,0 +1,8 @@
+package b
+
+import a.C
+import a.provideDelegate
+
+class Example {
+    val c: C by C()
+}

idea/testData/editor/optimizeImports/common/ProvideDelegate2.kt.after

@@ -0,0 +1,8 @@
+package b
+
+import a.C
+import a.provideDelegate
+
+class Example {
+    val c: C by C()
+}

idea/testData/inspections/unusedImport/inspectionData/expected.xml

@@ -106,4 +106,13 @@
         <problem_class severity="WARNING" attribute_key="NOT_USED_ELEMENT_ATTRIBUTES">Unused import directive</problem_class>
         <description>Unused import directive</description>
     </problem>
+
+    <problem>
+        <file>provideDelegate.kt</file>
+        <line>2</line>
+        <module>light_idea_test_case</module>
+        <entry_point TYPE="file" FQNAME="provideDelegate.kt" />
+        <problem_class severity="WARNING" attribute_key="NOT_USED_ELEMENT_ATTRIBUTES">Unused import directive</problem_class>
+        <description>Unused import directive</description>
+    </problem>
 </problems>

idea/testData/inspections/unusedImport/noUnusedProvideDelegate.Dependency.kt

@@ -0,0 +1,7 @@
+package onetwo
+
+import kotlin.properties.ReadOnlyProperty
+import kotlin.reflect.KProperty
+
+class C
+operator fun C.provideDelegate(thisRef: Any, prop: KProperty<*>): ReadOnlyProperty<Any, C> = TODO()

idea/testData/inspections/unusedImport/noUnusedProvideDelegate.kt

@@ -0,0 +1,6 @@
+import onetwo.C
+import onetwo.provideDelegate
+
+class Example {
+    val c: C by C()
+}

idea/testData/inspections/unusedImport/provideDelegate.Dependency.kt

@@ -0,0 +1,7 @@
+package a
+
+import kotlin.properties.ReadOnlyProperty
+import kotlin.reflect.KProperty
+
+class C
+operator fun C.provideDelegate(thisRef: Any, prop: KProperty<*>): ReadOnlyProperty<Any, C> = TODO()

idea/testData/inspections/unusedImport/provideDelegate.kt

@@ -0,0 +1,6 @@
+import a.C
+import a.provideDelegate
+
+class Example {
+    val c = C()
+}

idea/tests/org/jetbrains/kotlin/idea/imports/JsOptimizeImportsTestGenerated.java

@@ -179,6 +179,16 @@ public class JsOptimizeImportsTestGenerated extends AbstractJsOptimizeImportsTes
             runTest("idea/testData/editor/optimizeImports/common/Overloads.kt");
         }
 
+        @TestMetadata("ProvideDelegate.kt")
+        public void testProvideDelegate() throws Exception {
+            runTest("idea/testData/editor/optimizeImports/common/ProvideDelegate.kt");
+        }
+
+        @TestMetadata("ProvideDelegate2.kt")
+        public void testProvideDelegate2() throws Exception {
+            runTest("idea/testData/editor/optimizeImports/common/ProvideDelegate2.kt");
+        }
+
         @TestMetadata("TwoConstructors.kt")
         public void testTwoConstructors() throws Exception {
             runTest("idea/testData/editor/optimizeImports/common/TwoConstructors.kt");

idea/tests/org/jetbrains/kotlin/idea/imports/JvmOptimizeImportsTestGenerated.java

@@ -372,6 +372,16 @@ public class JvmOptimizeImportsTestGenerated extends AbstractJvmOptimizeImportsT
             runTest("idea/testData/editor/optimizeImports/common/Overloads.kt");
         }
 
+        @TestMetadata("ProvideDelegate.kt")
+        public void testProvideDelegate() throws Exception {
+            runTest("idea/testData/editor/optimizeImports/common/ProvideDelegate.kt");
+        }
+
+        @TestMetadata("ProvideDelegate2.kt")
+        public void testProvideDelegate2() throws Exception {
+            runTest("idea/testData/editor/optimizeImports/common/ProvideDelegate2.kt");
+        }
+
         @TestMetadata("TwoConstructors.kt")
         public void testTwoConstructors() throws Exception {
             runTest("idea/testData/editor/optimizeImports/common/TwoConstructors.kt");