Convert reference to lambda: correct handling of static method references #KT-14982 Fixed

idea/src/org/jetbrains/kotlin/idea/intentions/ConvertReferenceToLambdaIntention.kt

@@ -30,7 +30,6 @@ import org.jetbrains.kotlin.resolve.BindingContext.DOUBLE_COLON_LHS
 import org.jetbrains.kotlin.resolve.BindingContext.REFERENCE_TARGET
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
 import org.jetbrains.kotlin.types.expressions.DoubleColonLHS
-import org.jetbrains.kotlin.utils.singletonOrEmptyList
 
 class ConvertReferenceToLambdaInspection : IntentionBasedInspection<KtCallableReferenceExpression>(ConvertReferenceToLambdaIntention::class)
 
@@ -51,23 +50,31 @@ class ConvertReferenceToLambdaIntention : SelfTargetingOffsetIndependentIntentio
         val receiverNameAndType = receiverType?.let { KotlinNameSuggester.suggestNamesByType(it, validator = {
             name -> name !in parameterNamesAndTypes.map { it.first }
         }, defaultName = "receiver").first() to it }
+        val acceptsReceiverAsParameter = receiverNameAndType != null &&
+                                         (targetDescriptor.dispatchReceiverParameter != null ||
+                                          targetDescriptor.extensionReceiverParameter != null)
 
         val referenceParent = element.parent
         val insideCall = referenceParent is KtValueArgument
 
         val factory = KtPsiFactory(element)
         val targetName = reference.text
-        val lambdaParameterNamesAndTypes = receiverNameAndType.singletonOrEmptyList() + parameterNamesAndTypes
-        val receiverPrefix = receiverNameAndType?.let { it.first + "." } ?: ""
+        val lambdaParameterNamesAndTypes =
+                if (acceptsReceiverAsParameter) listOf(receiverNameAndType!!) + parameterNamesAndTypes
+                else parameterNamesAndTypes
+
+        val receiverPrefix =
+                if (acceptsReceiverAsParameter) receiverNameAndType!!.first + "."
+                else receiverExpression?.let { it.text + "." } ?: ""
         val lambdaExpression = if (insideCall && lambdaParameterNamesAndTypes.size == 1) {
             factory.createLambdaExpression(
                     parameters = "",
                     body = when {
-                        receiverNameAndType != null ->
+                        acceptsReceiverAsParameter ->
                             if (targetDescriptor is PropertyDescriptor) "it.$targetName"
                             else "it.$targetName()"
                         else ->
-                            "$targetName(it)"
+                            "$receiverPrefix$targetName(it)"
                     }
             )
         }

idea/testData/intentions/convertReferenceToLambda/companion.kt

+// WITH_RUNTIME
+
+import Utils.Companion.foo
+
+val list = listOf(1, 2, 3).map(<caret>::foo)
+
+class Utils {
+    companion object {
+        fun foo(x: Int) = x
+    }
+}
\ No newline at end of file

idea/testData/intentions/convertReferenceToLambda/companion.kt.after

+// WITH_RUNTIME
+
+import Utils.Companion.foo
+
+val list = listOf(1, 2, 3).map { foo(it) }
+
+class Utils {
+    companion object {
+        fun foo(x: Int) = x
+    }
+}
\ No newline at end of file

idea/testData/intentions/convertReferenceToLambda/object.kt

+// IS_APPLICABLE: false
+// WITH_RUNTIME
+val list = listOf(1, 2, 3).map(<caret>Utils::foo)
+
+object Utils {
+    fun foo(x: Int) = x
+}
\ No newline at end of file

idea/testData/intentions/convertReferenceToLambda/static.1.java

+class Utils {
+    public static int foo(int arg) { return arg; }
+}
\ No newline at end of file

idea/testData/intentions/convertReferenceToLambda/static.1.java.after

+class Utils {
+    public static int foo(int arg) { return arg; }
+}
\ No newline at end of file

idea/testData/intentions/convertReferenceToLambda/static.kt

+// WITH_RUNTIME
+val list = listOf(1, 2, 3).map(<caret>Utils::foo)
\ No newline at end of file

idea/testData/intentions/convertReferenceToLambda/static.kt.after

+// WITH_RUNTIME
+val list = listOf(1, 2, 3).map { Utils.foo(it) }
\ No newline at end of file

idea/testData/intentions/convertReferenceToLambda/staticTwoParameters.1.java

+class Utils {
+    public static int foo(int x, int y) { return x + y; }
+}
\ No newline at end of file

idea/testData/intentions/convertReferenceToLambda/staticTwoParameters.1.java.after

+class Utils {
+    public static int foo(int x, int y) { return x + y; }
+}
\ No newline at end of file

idea/testData/intentions/convertReferenceToLambda/staticTwoParameters.kt

+val x = <caret>Utils::foo
\ No newline at end of file

idea/testData/intentions/convertReferenceToLambda/staticTwoParameters.kt.after

+val x = { x: Int, y: Int -> Utils.foo(x, y) }
\ No newline at end of file

idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java

@@ -4967,6 +4967,12 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             doTest(fileName);
         }
 
+        @TestMetadata("companion.kt")
+        public void testCompanion() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/convertReferenceToLambda/companion.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("constructor.kt")
         public void testConstructor() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/convertReferenceToLambda/constructor.kt");
@@ -5015,6 +5021,12 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             doTest(fileName);
         }
 
+        @TestMetadata("object.kt")
+        public void testObject() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/convertReferenceToLambda/object.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("receiverParameter.kt")
         public void testReceiverParameter() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/convertReferenceToLambda/receiverParameter.kt");
@@ -5027,6 +5039,18 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             doTest(fileName);
         }
 
+        @TestMetadata("static.kt")
+        public void testStatic() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/convertReferenceToLambda/static.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("staticTwoParameters.kt")
+        public void testStaticTwoParameters() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/convertReferenceToLambda/staticTwoParameters.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("threeParameters.kt")
         public void testThreeParameters() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/convertReferenceToLambda/threeParameters.kt");