From f7a69d4aa7e3a4a47f4e6280dd2afed3cfbd4949 Mon Sep 17 00:00:00 2001
From: Toshiaki Kameyama <kmymtsak@gmail.com>
Date: Mon, 2 Mar 2020 10:22:27 +0900
Subject: [PATCH] Convert lambda to reference: suggest on lambda argument for
 suspend function parameter

#KT-34378 Fixed
---
 .../idea/intentions/ConvertLambdaToReferenceIntention.kt   | 7 ++++---
 .../convertLambdaToReference/suspendFunctionParameter2.kt  | 7 +++++++
 .../suspendFunctionParameter2.kt.after                     | 7 +++++++
 .../kotlin/idea/intentions/IntentionTestGenerated.java     | 5 +++++
 4 files changed, 23 insertions(+), 3 deletions(-)
 create mode 100644 idea/testData/intentions/convertLambdaToReference/suspendFunctionParameter2.kt
 create mode 100644 idea/testData/intentions/convertLambdaToReference/suspendFunctionParameter2.kt.after

diff --git a/idea/src/org/jetbrains/kotlin/idea/intentions/ConvertLambdaToReferenceIntention.kt b/idea/src/org/jetbrains/kotlin/idea/intentions/ConvertLambdaToReferenceIntention.kt
index ee5bfa99000..2a63d9f94d6 100644
--- a/idea/src/org/jetbrains/kotlin/idea/intentions/ConvertLambdaToReferenceIntention.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/intentions/ConvertLambdaToReferenceIntention.kt
@@ -72,19 +72,20 @@ open class ConvertLambdaToReferenceIntention(textGetter: () -> String) : SelfTar
         val calleeDescriptor = context[REFERENCE_TARGET, calleeReferenceExpression] as? CallableMemberDescriptor ?: return false
 
         val lambdaParameterType = lambdaExpression.lambdaParameterType(context)
-        if (lambdaParameterType?.isSuspendFunctionType == true) return false
         if (lambdaParameterType?.isExtensionFunctionType == true) {
             if (explicitReceiver != null && explicitReceiver !is KtThisExpression) return false
             val receiver = calleeDescriptor.dispatchReceiverParameter ?: calleeDescriptor.extensionReceiverParameter
             if (lambdaParameterType.getReceiverTypeFromFunctionType() != receiver?.type) return false
         }
 
+        val lambdaParameterIsSuspend = lambdaParameterType?.isSuspendFunctionType == true
+        val calleeFunctionIsSuspend = (calleeDescriptor as? FunctionDescriptor)?.isSuspend == true
+        if (lambdaParameterIsSuspend && !calleeFunctionIsSuspend || !lambdaParameterIsSuspend && calleeFunctionIsSuspend) return false
+
         // No references with type parameters
         if (calleeDescriptor.typeParameters.isNotEmpty()) return false
         // No references to Java synthetic properties
         if (calleeDescriptor is SyntheticJavaPropertyDescriptor) return false
-        // No suspend functions
-        if ((calleeDescriptor as? FunctionDescriptor)?.isSuspend == true) return false
 
         val descriptorHasReceiver = with(calleeDescriptor) {
             // No references to both member / extension
diff --git a/idea/testData/intentions/convertLambdaToReference/suspendFunctionParameter2.kt b/idea/testData/intentions/convertLambdaToReference/suspendFunctionParameter2.kt
new file mode 100644
index 00000000000..112f1f4df4a
--- /dev/null
+++ b/idea/testData/intentions/convertLambdaToReference/suspendFunctionParameter2.kt
@@ -0,0 +1,7 @@
+fun foo(a: suspend () -> Unit) {}
+
+suspend fun action() {}
+
+fun usage() {
+    foo { action() <caret> }
+}
\ No newline at end of file
diff --git a/idea/testData/intentions/convertLambdaToReference/suspendFunctionParameter2.kt.after b/idea/testData/intentions/convertLambdaToReference/suspendFunctionParameter2.kt.after
new file mode 100644
index 00000000000..3c2d3a61329
--- /dev/null
+++ b/idea/testData/intentions/convertLambdaToReference/suspendFunctionParameter2.kt.after
@@ -0,0 +1,7 @@
+fun foo(a: suspend () -> Unit) {}
+
+suspend fun action() {}
+
+fun usage() {
+    foo(::action)
+}
\ No newline at end of file
diff --git a/idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java b/idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java
index 2ca44193d51..550ff0610a6 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java
+++ b/idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java
@@ -5165,6 +5165,11 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             runTest("idea/testData/intentions/convertLambdaToReference/suspendFunctionParameter.kt");
         }
 
+        @TestMetadata("suspendFunctionParameter2.kt")
+        public void testSuspendFunctionParameter2() throws Exception {
+            runTest("idea/testData/intentions/convertLambdaToReference/suspendFunctionParameter2.kt");
+        }
+
         @TestMetadata("syntheticProperty.kt")
         public void testSyntheticProperty() throws Exception {
             runTest("idea/testData/intentions/convertLambdaToReference/syntheticProperty.kt");