From c44cab4565dbec6a3d44349f2f959fa34337b420 Mon Sep 17 00:00:00 2001
From: Toshiaki Kameyama <kmymtsak@gmail.com>
Date: Wed, 25 Apr 2018 07:39:33 +0300
Subject: [PATCH] "Redundant Unit" inspection: Fix for labeled return #KT-23977
 Fixed

---
 .../RedundantUnitExpressionInspection.kt      | 21 ++++++++++++++++++-
 .../labeledReturnAny.kt                       |  9 ++++++++
 .../labeledReturnAnyInValueArgument.kt        |  7 +++++++
 .../labeledReturnGenericType.kt               |  7 +++++++
 .../labeledReturnGenericType.kt.after         |  7 +++++++
 .../labeledReturnUnit.kt                      |  7 +++++++
 .../labeledReturnUnit.kt.after                |  7 +++++++
 .../LocalInspectionTestGenerated.java         | 20 ++++++++++++++++++
 8 files changed, 84 insertions(+), 1 deletion(-)
 create mode 100644 idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnAny.kt
 create mode 100644 idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnAnyInValueArgument.kt
 create mode 100644 idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnGenericType.kt
 create mode 100644 idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnGenericType.kt.after
 create mode 100644 idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnUnit.kt
 create mode 100644 idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnUnit.kt.after

diff --git a/idea/src/org/jetbrains/kotlin/idea/inspections/RedundantUnitExpressionInspection.kt b/idea/src/org/jetbrains/kotlin/idea/inspections/RedundantUnitExpressionInspection.kt
index cdd92c39807..d5d7e15f54b 100644
--- a/idea/src/org/jetbrains/kotlin/idea/inspections/RedundantUnitExpressionInspection.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/inspections/RedundantUnitExpressionInspection.kt
@@ -10,10 +10,13 @@ import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiElementVisitor
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.idea.caches.resolve.resolveToCall
+import org.jetbrains.kotlin.idea.intentions.getCallableDescriptor
 import org.jetbrains.kotlin.idea.intentions.loopToCallChain.previousStatement
+import org.jetbrains.kotlin.js.descriptorUtils.nameIfStandardType
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.getParentOfType
 import org.jetbrains.kotlin.psi.psiUtil.getParentOfTypesAndPredicate
+import org.jetbrains.kotlin.psi.psiUtil.getStrictParentOfType
 import org.jetbrains.kotlin.psi.psiUtil.lastBlockStatementOrThis
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
 import org.jetbrains.kotlin.types.typeUtil.isUnit
@@ -36,7 +39,23 @@ class RedundantUnitExpressionInspection : AbstractKotlinInspection(), CleanupLoc
 private fun KtReferenceExpression.isRedundantUnit(): Boolean {
     if (!isUnitLiteral()) return false
     val parent = this.parent ?: return false
-    if (parent is KtReturnExpression) return true
+    if (parent is KtReturnExpression) {
+        if (parent.labeledExpression != null) {
+            val functionLiteral = parent.getStrictParentOfType<KtFunctionLiteral>()
+            val callExpression = functionLiteral?.getStrictParentOfType<KtCallExpression>()
+            if (functionLiteral != null && callExpression != null) {
+                val valueArgument = functionLiteral.getStrictParentOfType<KtValueArgument>()
+                val index = if (valueArgument != null)
+                    callExpression.valueArguments.indexOf(valueArgument)
+                else
+                    callExpression.valueArguments.size - 1
+                val parameter = callExpression.getCallableDescriptor()?.valueParameters?.getOrNull(index)
+                val returnType = parameter?.returnType?.arguments?.firstOrNull()?.type
+                if (returnType?.nameIfStandardType == KotlinBuiltIns.FQ_NAMES.any.shortName()) return false
+            }
+        }
+        return true
+    }
     if (parent is KtBlockExpression) {
         // Do not report just 'Unit' in function literals (return@label Unit is OK even in literals)
         if (parent.getParentOfType<KtFunctionLiteral>(strict = true) != null) return false
diff --git a/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnAny.kt b/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnAny.kt
new file mode 100644
index 00000000000..2221577c7c4
--- /dev/null
+++ b/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnAny.kt
@@ -0,0 +1,9 @@
+// PROBLEM: none
+
+fun foo(f: () -> Any) {}
+
+fun test() {
+    foo {
+        return@foo Unit<caret>
+    }
+}
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnAnyInValueArgument.kt b/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnAnyInValueArgument.kt
new file mode 100644
index 00000000000..102a2f4cae4
--- /dev/null
+++ b/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnAnyInValueArgument.kt
@@ -0,0 +1,7 @@
+// PROBLEM: none
+
+fun foo(f: () -> Unit, g: () -> Any) {}
+
+fun test() {
+    foo({ return@foo Unit }, { return@foo Unit<caret> })
+}
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnGenericType.kt b/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnGenericType.kt
new file mode 100644
index 00000000000..2853726c339
--- /dev/null
+++ b/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnGenericType.kt
@@ -0,0 +1,7 @@
+fun <T> foo(f: () -> T) {}
+
+fun test() {
+    foo {
+        return@foo Unit<caret>
+    }
+}
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnGenericType.kt.after b/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnGenericType.kt.after
new file mode 100644
index 00000000000..cc316b7b5d6
--- /dev/null
+++ b/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnGenericType.kt.after
@@ -0,0 +1,7 @@
+fun <T> foo(f: () -> T) {}
+
+fun test() {
+    foo {
+        return@foo
+    }
+}
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnUnit.kt b/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnUnit.kt
new file mode 100644
index 00000000000..dec8e22091d
--- /dev/null
+++ b/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnUnit.kt
@@ -0,0 +1,7 @@
+fun foo(f: () -> Unit) {}
+
+fun test() {
+    foo {
+        return@foo Unit<caret>
+    }
+}
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnUnit.kt.after b/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnUnit.kt.after
new file mode 100644
index 00000000000..0c5fc6f7dac
--- /dev/null
+++ b/idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnUnit.kt.after
@@ -0,0 +1,7 @@
+fun foo(f: () -> Unit) {}
+
+fun test() {
+    foo {
+        return@foo
+    }
+}
\ 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 1a531bfccdd..4cf35e3962a 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
+++ b/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
@@ -3358,6 +3358,26 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
             runTest("idea/testData/inspectionsLocal/redundantUnitExpression/atLastAfterVal.kt");
         }
 
+        @TestMetadata("labeledReturnAny.kt")
+        public void testLabeledReturnAny() throws Exception {
+            runTest("idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnAny.kt");
+        }
+
+        @TestMetadata("labeledReturnAnyInValueArgument.kt")
+        public void testLabeledReturnAnyInValueArgument() throws Exception {
+            runTest("idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnAnyInValueArgument.kt");
+        }
+
+        @TestMetadata("labeledReturnGenericType.kt")
+        public void testLabeledReturnGenericType() throws Exception {
+            runTest("idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnGenericType.kt");
+        }
+
+        @TestMetadata("labeledReturnUnit.kt")
+        public void testLabeledReturnUnit() throws Exception {
+            runTest("idea/testData/inspectionsLocal/redundantUnitExpression/labeledReturnUnit.kt");
+        }
+
         @TestMetadata("lambda.kt")
         public void testLambda() throws Exception {
             runTest("idea/testData/inspectionsLocal/redundantUnitExpression/lambda.kt");