From c8c485d27e23dab061b3bd7179ac7bd7a60bbc9c Mon Sep 17 00:00:00 2001
From: Mikhail Glukhikh <mikhail.glukhikh@jetbrains.com>
Date: Thu, 6 Dec 2018 16:15:35 +0300
Subject: [PATCH] Redundant arrow: support removing of 'it ->' #KT-28631 Fixed

---
 .../idea/inspections/RedundantLambdaArrowInspection.kt |  4 +++-
 .../inspectionsLocal/redundantLambdaArrow/it.kt        | 10 ++++++++++
 .../inspectionsLocal/redundantLambdaArrow/it.kt.after  | 10 ++++++++++
 .../redundantLambdaArrow/underscore.kt                 |  2 +-
 .../redundantLambdaArrow/underscore.kt.after           |  2 +-
 .../idea/inspections/LocalInspectionTestGenerated.java |  5 +++++
 6 files changed, 30 insertions(+), 3 deletions(-)
 create mode 100644 idea/testData/inspectionsLocal/redundantLambdaArrow/it.kt
 create mode 100644 idea/testData/inspectionsLocal/redundantLambdaArrow/it.kt.after

diff --git a/idea/src/org/jetbrains/kotlin/idea/inspections/RedundantLambdaArrowInspection.kt b/idea/src/org/jetbrains/kotlin/idea/inspections/RedundantLambdaArrowInspection.kt
index a6da84cf852..8712fea2408 100644
--- a/idea/src/org/jetbrains/kotlin/idea/inspections/RedundantLambdaArrowInspection.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/inspections/RedundantLambdaArrowInspection.kt
@@ -30,7 +30,9 @@ class RedundantLambdaArrowInspection : AbstractKotlinInspection() {
             val arrow = functionLiteral.arrow ?: return@lambdaExpressionVisitor
             val parameters = functionLiteral.valueParameters
             val singleParameter = parameters.singleOrNull()
-            if (parameters.isNotEmpty() && singleParameter?.isSingleUnderscore != true) return@lambdaExpressionVisitor
+            if (parameters.isNotEmpty() && singleParameter?.isSingleUnderscore != true && singleParameter?.name != "it") {
+                return@lambdaExpressionVisitor
+            }
 
             if (lambdaExpression.getStrictParentOfType<KtWhenEntry>()?.expression == lambdaExpression) return@lambdaExpressionVisitor
             if (lambdaExpression.getStrictParentOfType<KtContainerNodeForControlStructureBody>()?.let {
diff --git a/idea/testData/inspectionsLocal/redundantLambdaArrow/it.kt b/idea/testData/inspectionsLocal/redundantLambdaArrow/it.kt
new file mode 100644
index 00000000000..d572186d082
--- /dev/null
+++ b/idea/testData/inspectionsLocal/redundantLambdaArrow/it.kt
@@ -0,0 +1,10 @@
+fun foo(f: (String) -> Unit) {}
+
+fun print(s: String) {}
+
+fun bar() {
+    foo { <caret>it ->
+        print(it)
+        print(it)
+    }
+}
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/redundantLambdaArrow/it.kt.after b/idea/testData/inspectionsLocal/redundantLambdaArrow/it.kt.after
new file mode 100644
index 00000000000..122075de34f
--- /dev/null
+++ b/idea/testData/inspectionsLocal/redundantLambdaArrow/it.kt.after
@@ -0,0 +1,10 @@
+fun foo(f: (String) -> Unit) {}
+
+fun print(s: String) {}
+
+fun bar() {
+    foo {
+        print(it)
+        print(it)
+    }
+}
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/redundantLambdaArrow/underscore.kt b/idea/testData/inspectionsLocal/redundantLambdaArrow/underscore.kt
index dfaa06f2fae..c9d732d1160 100644
--- a/idea/testData/inspectionsLocal/redundantLambdaArrow/underscore.kt
+++ b/idea/testData/inspectionsLocal/redundantLambdaArrow/underscore.kt
@@ -1,4 +1,4 @@
-fun foo(f: () -> Unit) {}
+fun foo(f: (String) -> Unit) {}
 
 fun bar() {
     foo { <caret>_ -> }
diff --git a/idea/testData/inspectionsLocal/redundantLambdaArrow/underscore.kt.after b/idea/testData/inspectionsLocal/redundantLambdaArrow/underscore.kt.after
index 2f5053d30e2..38c94b39254 100644
--- a/idea/testData/inspectionsLocal/redundantLambdaArrow/underscore.kt.after
+++ b/idea/testData/inspectionsLocal/redundantLambdaArrow/underscore.kt.after
@@ -1,4 +1,4 @@
-fun foo(f: () -> Unit) {}
+fun foo(f: (String) -> Unit) {}
 
 fun bar() {
     foo { <caret>}
diff --git a/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java b/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
index 7f7a95f0773..92a6630d32a 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
+++ b/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
@@ -4482,6 +4482,11 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
             runTest("idea/testData/inspectionsLocal/redundantLambdaArrow/inIfWhenEntry2.kt");
         }
 
+        @TestMetadata("it.kt")
+        public void testIt() throws Exception {
+            runTest("idea/testData/inspectionsLocal/redundantLambdaArrow/it.kt");
+        }
+
         @TestMetadata("simple.kt")
         public void testSimple() throws Exception {
             runTest("idea/testData/inspectionsLocal/redundantLambdaArrow/simple.kt");