From 7d89869c0214048566b6666e2d368e64b7acc3fa Mon Sep 17 00:00:00 2001
From: Denis Zharkov <denis.zharkov@jetbrains.com>
Date: Fri, 21 Oct 2016 13:13:28 +0300
Subject: [PATCH] Do not suggest "Remove parameter" quick-fix on lambdas

Only "Rename to _" should work in the case.

The problem is that removing lambda's parameter may lead behaviour changes.
This quick-fix was not being invoked run before KT-14347 had been implemented

# Conflicts:
#	idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixTestGenerated.java
---
 .../quickfix/RemoveUnusedFunctionParameterFix.kt   | 10 ++++++++--
 ...functionExpressionParameterNoRemoveParameter.kt | 13 +++++++++++++
 .../lambdaParameterNoRemoveParameter.kt            | 14 ++++++++++++++
 .../idea/quickfix/QuickFixTestGenerated.java       | 12 ++++++++++++
 4 files changed, 47 insertions(+), 2 deletions(-)
 create mode 100644 idea/testData/quickfix/renameToUnderscore/functionExpressionParameterNoRemoveParameter.kt
 create mode 100644 idea/testData/quickfix/renameToUnderscore/lambdaParameterNoRemoveParameter.kt

diff --git a/idea/src/org/jetbrains/kotlin/idea/quickfix/RemoveUnusedFunctionParameterFix.kt b/idea/src/org/jetbrains/kotlin/idea/quickfix/RemoveUnusedFunctionParameterFix.kt
index c535f27420d..326ee29668c 100644
--- a/idea/src/org/jetbrains/kotlin/idea/quickfix/RemoveUnusedFunctionParameterFix.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/quickfix/RemoveUnusedFunctionParameterFix.kt
@@ -23,6 +23,8 @@ import org.jetbrains.kotlin.diagnostics.Diagnostic
 import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.idea.caches.resolve.resolveToDescriptor
 import org.jetbrains.kotlin.psi.KtFile
+import org.jetbrains.kotlin.psi.KtFunctionLiteral
+import org.jetbrains.kotlin.psi.KtNamedFunction
 import org.jetbrains.kotlin.psi.KtParameter
 
 class RemoveUnusedFunctionParameterFix(parameter: KtParameter) : KotlinQuickFixAction<KtParameter>(parameter) {
@@ -38,8 +40,12 @@ class RemoveUnusedFunctionParameterFix(parameter: KtParameter) : KotlinQuickFixA
     }
 
     companion object : KotlinSingleIntentionActionFactory() {
-        override fun createAction(diagnostic: Diagnostic): KotlinQuickFixAction<KtParameter> {
-            return RemoveUnusedFunctionParameterFix(Errors.UNUSED_PARAMETER.cast(diagnostic).psiElement)
+        override fun createAction(diagnostic: Diagnostic): KotlinQuickFixAction<KtParameter>? {
+            val parameter = Errors.UNUSED_PARAMETER.cast(diagnostic).psiElement
+            val parameterOwner = parameter.parent.parent
+            if (parameterOwner is KtFunctionLiteral ||
+                    (parameterOwner is KtNamedFunction && parameterOwner.name == null)) return null
+            return RemoveUnusedFunctionParameterFix(parameter)
         }
     }
 }
diff --git a/idea/testData/quickfix/renameToUnderscore/functionExpressionParameterNoRemoveParameter.kt b/idea/testData/quickfix/renameToUnderscore/functionExpressionParameterNoRemoveParameter.kt
new file mode 100644
index 00000000000..1ede27f0275
--- /dev/null
+++ b/idea/testData/quickfix/renameToUnderscore/functionExpressionParameterNoRemoveParameter.kt
@@ -0,0 +1,13 @@
+// "Remove parameter 'x'" "false"
+// ACTION: Add 'block =' to argument
+// ACTION: Convert parameter to receiver
+// ACTION: Rename to _
+// ACTION: Specify return type explicitly
+
+fun foo(block: (String, Int) -> Unit) {
+    block("", 1)
+}
+
+fun bar() {
+    foo(fun(x<caret>: String, y: Int) = Unit)
+}
diff --git a/idea/testData/quickfix/renameToUnderscore/lambdaParameterNoRemoveParameter.kt b/idea/testData/quickfix/renameToUnderscore/lambdaParameterNoRemoveParameter.kt
new file mode 100644
index 00000000000..d61be95a8b0
--- /dev/null
+++ b/idea/testData/quickfix/renameToUnderscore/lambdaParameterNoRemoveParameter.kt
@@ -0,0 +1,14 @@
+// "Remove parameter 'x'" "false"
+// ACTION: Move lambda argument into parentheses
+// ACTION: Remove explicit lambda parameter types (may break code)
+// ACTION: Rename to _
+
+fun foo(block: (String, Int) -> Unit) {
+    block("", 1)
+}
+
+fun bar() {
+    foo { x<caret>: String, y: Int ->
+        y.hashCode()
+    }
+}
diff --git a/idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixTestGenerated.java b/idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixTestGenerated.java
index 9902af6f332..2171755b4b1 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixTestGenerated.java
+++ b/idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixTestGenerated.java
@@ -7439,6 +7439,12 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
             doTest(fileName);
         }
 
+        @TestMetadata("functionExpressionParameterNoRemoveParameter.kt")
+        public void testFunctionExpressionParameterNoRemoveParameter() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/renameToUnderscore/functionExpressionParameterNoRemoveParameter.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("lambdaDestructuring.kt")
         public void testLambdaDestructuring() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/renameToUnderscore/lambdaDestructuring.kt");
@@ -7451,6 +7457,12 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
             doTest(fileName);
         }
 
+        @TestMetadata("lambdaParameterNoRemoveParameter.kt")
+        public void testLambdaParameterNoRemoveParameter() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/renameToUnderscore/lambdaParameterNoRemoveParameter.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("noActionForCommonVal.kt")
         public void testNoActionForCommonVal() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/renameToUnderscore/noActionForCommonVal.kt");