From de3907e8cce008dc132a20f6e308c273b90c46b9 Mon Sep 17 00:00:00 2001
From: Toshiaki Kameyama <kmymtsak@gmail.com>
Date: Fri, 11 Sep 2020 09:50:57 +0900
Subject: [PATCH] Redundant nullable return type: fix false positive with
 non-local return

#KT-41800 Fixed
---
 .../RedundantNullableReturnTypeInspection.kt      |  9 +++++----
 .../returnNullableFromLambdaInBlockBody.kt        |  9 +++++++++
 ...urnNullableFromLambdaInSingleExpressionBody.kt |  5 +++++
 .../property/returnNullableFromLambdaInGetter.kt  |  6 ++++++
 .../inspections/LocalInspectionTestGenerated.java | 15 +++++++++++++++
 5 files changed, 40 insertions(+), 4 deletions(-)
 create mode 100644 idea/testData/inspectionsLocal/redundantNullableReturnType/function/returnNullableFromLambdaInBlockBody.kt
 create mode 100644 idea/testData/inspectionsLocal/redundantNullableReturnType/function/returnNullableFromLambdaInSingleExpressionBody.kt
 create mode 100644 idea/testData/inspectionsLocal/redundantNullableReturnType/property/returnNullableFromLambdaInGetter.kt

diff --git a/idea/src/org/jetbrains/kotlin/idea/inspections/RedundantNullableReturnTypeInspection.kt b/idea/src/org/jetbrains/kotlin/idea/inspections/RedundantNullableReturnTypeInspection.kt
index 3506e801664..33470bfc281 100644
--- a/idea/src/org/jetbrains/kotlin/idea/inspections/RedundantNullableReturnTypeInspection.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/inspections/RedundantNullableReturnTypeInspection.kt
@@ -74,12 +74,13 @@ class RedundantNullableReturnTypeInspection : AbstractKotlinInspection() {
         val dataFlowValueFactory = getResolutionFacade().getDataFlowValueFactory()
         val moduleDescriptor = findModuleDescriptor()
         val languageVersionSettings = languageVersionSettings
+        val returnTypes = collectDescendantsOfType<KtReturnExpression>().flatMap {
+            it.returnedExpression.types(context, dataFlowValueFactory, moduleDescriptor, languageVersionSettings)
+        }
         return if (this is KtBlockExpression) {
-            collectDescendantsOfType<KtReturnExpression>().flatMap {
-                it.returnedExpression.types(context, dataFlowValueFactory, moduleDescriptor, languageVersionSettings)
-            }
+            returnTypes
         } else {
-            types(context, dataFlowValueFactory, moduleDescriptor, languageVersionSettings)
+            returnTypes + types(context, dataFlowValueFactory, moduleDescriptor, languageVersionSettings)
         }
     }
 
diff --git a/idea/testData/inspectionsLocal/redundantNullableReturnType/function/returnNullableFromLambdaInBlockBody.kt b/idea/testData/inspectionsLocal/redundantNullableReturnType/function/returnNullableFromLambdaInBlockBody.kt
new file mode 100644
index 00000000000..d0f48e20cbe
--- /dev/null
+++ b/idea/testData/inspectionsLocal/redundantNullableReturnType/function/returnNullableFromLambdaInBlockBody.kt
@@ -0,0 +1,9 @@
+// PROBLEM: none
+class MyClass
+
+inline fun <T> acceptMyClass(m: (MyClass?) -> T) {}
+
+fun one(): MyClass?<caret> {
+    acceptMyClass { return it }
+    return MyClass()
+}
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/redundantNullableReturnType/function/returnNullableFromLambdaInSingleExpressionBody.kt b/idea/testData/inspectionsLocal/redundantNullableReturnType/function/returnNullableFromLambdaInSingleExpressionBody.kt
new file mode 100644
index 00000000000..c6a030fec11
--- /dev/null
+++ b/idea/testData/inspectionsLocal/redundantNullableReturnType/function/returnNullableFromLambdaInSingleExpressionBody.kt
@@ -0,0 +1,5 @@
+// PROBLEM: none
+// WITH_RUNTIME
+fun test(str: String): String?<caret> = str.run {
+    return null
+}
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/redundantNullableReturnType/property/returnNullableFromLambdaInGetter.kt b/idea/testData/inspectionsLocal/redundantNullableReturnType/property/returnNullableFromLambdaInGetter.kt
new file mode 100644
index 00000000000..1c20150e6fb
--- /dev/null
+++ b/idea/testData/inspectionsLocal/redundantNullableReturnType/property/returnNullableFromLambdaInGetter.kt
@@ -0,0 +1,6 @@
+// PROBLEM: none
+// WITH_RUNTIME
+val test: Int?<caret>
+    get() = run {
+        return null
+    }
\ No newline at end of file
diff --git a/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java b/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
index abd48238dde..e1183f17a25 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
+++ b/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
@@ -8249,6 +8249,16 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
                 runTest("idea/testData/inspectionsLocal/redundantNullableReturnType/function/overridable.kt");
             }
 
+            @TestMetadata("returnNullableFromLambdaInBlockBody.kt")
+            public void testReturnNullableFromLambdaInBlockBody() throws Exception {
+                runTest("idea/testData/inspectionsLocal/redundantNullableReturnType/function/returnNullableFromLambdaInBlockBody.kt");
+            }
+
+            @TestMetadata("returnNullableFromLambdaInSingleExpressionBody.kt")
+            public void testReturnNullableFromLambdaInSingleExpressionBody() throws Exception {
+                runTest("idea/testData/inspectionsLocal/redundantNullableReturnType/function/returnNullableFromLambdaInSingleExpressionBody.kt");
+            }
+
             @TestMetadata("singleExpressionBody.kt")
             public void testSingleExpressionBody() throws Exception {
                 runTest("idea/testData/inspectionsLocal/redundantNullableReturnType/function/singleExpressionBody.kt");
@@ -8287,6 +8297,11 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
                 runTest("idea/testData/inspectionsLocal/redundantNullableReturnType/property/initializer.kt");
             }
 
+            @TestMetadata("returnNullableFromLambdaInGetter.kt")
+            public void testReturnNullableFromLambdaInGetter() throws Exception {
+                runTest("idea/testData/inspectionsLocal/redundantNullableReturnType/property/returnNullableFromLambdaInGetter.kt");
+            }
+
             @TestMetadata("var.kt")
             public void testVar() throws Exception {
                 runTest("idea/testData/inspectionsLocal/redundantNullableReturnType/property/var.kt");