Suspend call detector: fix delegated properties checking

idea/src/org/jetbrains/kotlin/idea/highlighter/KotlinSuspendCallLineMarkerProvider.kt

@@ -24,11 +24,14 @@ import com.intellij.openapi.editor.markup.GutterIconRenderer
 import com.intellij.openapi.progress.ProgressManager
 import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
+import org.jetbrains.kotlin.descriptors.VariableDescriptorWithAccessors
+import org.jetbrains.kotlin.descriptors.accessors
 import org.jetbrains.kotlin.idea.KotlinIcons
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.refactoring.getLineNumber
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.BindingContext.*
 import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
 
@@ -76,7 +79,7 @@ class KotlinSuspendCallLineMarkerProvider : LineMarkerProvider {
 }
 
 private fun KtExpression.isValidCandidateExpression(): Boolean {
-    if (this is KtOperationReferenceExpression || this is KtForExpression) return true
+    if (this is KtOperationReferenceExpression || this is KtForExpression || this is KtProperty) return true
     val parent = parent
     if (parent is KtCallExpression && parent.calleeExpression == this) return true
     return false
@@ -87,13 +90,26 @@ fun KtExpression.hasSuspendCalls(bindingContext: BindingContext = analyze(BodyRe
 
     return when (this) {
         is KtForExpression -> {
-            val iteratorResolvedCall = bindingContext[BindingContext.LOOP_RANGE_ITERATOR_RESOLVED_CALL, loopRange]
-            val loopRangeHasNextResolvedCall = bindingContext[BindingContext.LOOP_RANGE_HAS_NEXT_RESOLVED_CALL, loopRange]
-            val loopRangeNextResolvedCall = bindingContext[BindingContext.LOOP_RANGE_NEXT_RESOLVED_CALL, loopRange]
+            val iteratorResolvedCall = bindingContext[LOOP_RANGE_ITERATOR_RESOLVED_CALL, loopRange]
+            val loopRangeHasNextResolvedCall = bindingContext[LOOP_RANGE_HAS_NEXT_RESOLVED_CALL, loopRange]
+            val loopRangeNextResolvedCall = bindingContext[LOOP_RANGE_NEXT_RESOLVED_CALL, loopRange]
             listOf(iteratorResolvedCall, loopRangeHasNextResolvedCall, loopRangeNextResolvedCall).any {
                 it?.resultingDescriptor?.isSuspend == true
             }
         }
+        is KtProperty -> {
+            if (hasDelegateExpression()) {
+                val variableDescriptor = bindingContext[DECLARATION_TO_DESCRIPTOR, this] as? VariableDescriptorWithAccessors
+                val accessors = variableDescriptor?.accessors ?: emptyList()
+                accessors.any { accessor ->
+                    val delegatedFunctionDescriptor = bindingContext[DELEGATED_PROPERTY_RESOLVED_CALL, accessor]?.resultingDescriptor
+                    delegatedFunctionDescriptor?.isSuspend == true
+                }
+            }
+            else {
+                false
+            }
+        }
         else -> {
             val resolvedCall = getResolvedCall(bindingContext)
             (resolvedCall?.resultingDescriptor as? FunctionDescriptor)?.isSuspend == true

idea/testData/inspectionsLocal/redundantSuspend/.inspection

@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.inspections.RedundantSuspendModifierInspection

idea/testData/inspectionsLocal/redundantSuspend/getterDelegate.kt

@@ -0,0 +1,13 @@
+// PROBLEM: none
+// WITH_RUNTIME
+
+import kotlin.reflect.KProperty
+
+<caret>suspend fun bar(): String {
+    val x: String by Delegate()
+    return x
+}
+
+class Delegate {
+    suspend operator fun getValue(thisRef: Any?, property: KProperty<*>): String = ""
+}

idea/testData/inspectionsLocal/redundantSuspend/setterDelegate.kt

@@ -0,0 +1,16 @@
+// PROBLEM: none
+// WITH_RUNTIME
+
+import kotlin.reflect.KProperty
+
+<caret>suspend fun bar(): String {
+    var x: String by Delegate()
+    x = "Hello"
+    return x
+}
+
+class Delegate {
+    operator fun getValue(thisRef: Any?, property: KProperty<*>): String = ""
+
+    suspend operator fun setValue(thisRef: Any?, property: KProperty<*>, value: String) {}
+}

idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java

@@ -1977,6 +1977,27 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
         }
     }
 
+    @TestMetadata("idea/testData/inspectionsLocal/redundantSuspend")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class RedundantSuspend extends AbstractLocalInspectionTest {
+        public void testAllFilesPresentInRedundantSuspend() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/inspectionsLocal/redundantSuspend"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("getterDelegate.kt")
+        public void testGetterDelegate() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/redundantSuspend/getterDelegate.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("setterDelegate.kt")
+        public void testSetterDelegate() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/redundantSuspend/setterDelegate.kt");
+            doTest(fileName);
+        }
+    }
+
     @TestMetadata("idea/testData/inspectionsLocal/redundantUnitExpression")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)