From 6c2eb06351e22e9491116114421032a2b2436897 Mon Sep 17 00:00:00 2001
From: Mikhail Glukhikh <Mikhail.Glukhikh@jetbrains.com>
Date: Mon, 23 Oct 2017 19:13:46 +0300
Subject: [PATCH] Do not report "unused receiver" on companion objects

So #KT-19560 Fixed
---
 .../UnusedReceiverParameterInspection.kt            |  4 ++++
 .../unusedReceiverParameter/companionPure.kt        | 13 +++++++++++++
 .../unusedReceiverParameter/object.kt               |  8 ++++++++
 .../unusedReceiverParameter/object.kt.after         |  8 ++++++++
 .../inspections/LocalInspectionTestGenerated.java   | 12 ++++++++++++
 5 files changed, 45 insertions(+)
 create mode 100644 idea/testData/inspectionsLocal/unusedReceiverParameter/companionPure.kt
 create mode 100644 idea/testData/inspectionsLocal/unusedReceiverParameter/object.kt
 create mode 100644 idea/testData/inspectionsLocal/unusedReceiverParameter/object.kt.after

diff --git a/idea/src/org/jetbrains/kotlin/idea/inspections/UnusedReceiverParameterInspection.kt b/idea/src/org/jetbrains/kotlin/idea/inspections/UnusedReceiverParameterInspection.kt
index 9e58c961e2d..3cbdceaca3e 100644
--- a/idea/src/org/jetbrains/kotlin/idea/inspections/UnusedReceiverParameterInspection.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/inspections/UnusedReceiverParameterInspection.kt
@@ -50,6 +50,10 @@ class UnusedReceiverParameterInspection : AbstractKotlinInspection() {
                 val receiverTypeReference = callableDeclaration.receiverTypeReference
                 if (receiverTypeReference == null || receiverTypeReference.textRange.isEmpty) return
 
+                val context = receiverTypeReference.analyze()
+                val receiverType = context[BindingContext.TYPE, receiverTypeReference] ?: return
+                if (DescriptorUtils.isCompanionObject(receiverType.constructor.declarationDescriptor)) return
+
                 if (callableDeclaration.isOverridable() ||
                     callableDeclaration.hasModifier(KtTokens.OVERRIDE_KEYWORD) ||
                     callableDeclaration.hasModifier(KtTokens.OPERATOR_KEYWORD) ||
diff --git a/idea/testData/inspectionsLocal/unusedReceiverParameter/companionPure.kt b/idea/testData/inspectionsLocal/unusedReceiverParameter/companionPure.kt
new file mode 100644
index 00000000000..a6244c6bb17
--- /dev/null
+++ b/idea/testData/inspectionsLocal/unusedReceiverParameter/companionPure.kt
@@ -0,0 +1,13 @@
+// PROBLEM: none
+
+class Test {
+    companion object {
+
+    }
+}
+
+fun <caret>Test.Companion.foo() = 42
+
+fun main(args: Array<String>) {
+    Test.foo()
+}
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/unusedReceiverParameter/object.kt b/idea/testData/inspectionsLocal/unusedReceiverParameter/object.kt
new file mode 100644
index 00000000000..81f4df19da6
--- /dev/null
+++ b/idea/testData/inspectionsLocal/unusedReceiverParameter/object.kt
@@ -0,0 +1,8 @@
+object Test
+
+fun <caret>Test.foo() = 42
+
+fun main(args: Array<String>) {
+    val x = Test
+    x.foo()
+}
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/unusedReceiverParameter/object.kt.after b/idea/testData/inspectionsLocal/unusedReceiverParameter/object.kt.after
new file mode 100644
index 00000000000..26977295ae5
--- /dev/null
+++ b/idea/testData/inspectionsLocal/unusedReceiverParameter/object.kt.after
@@ -0,0 +1,8 @@
+object Test
+
+fun foo() = 42
+
+fun main(args: Array<String>) {
+    val x = Test
+    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 fc40139b995..c9f69264649 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
+++ b/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
@@ -2327,12 +2327,24 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
             doTest(fileName);
         }
 
+        @TestMetadata("companionPure.kt")
+        public void testCompanionPure() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/unusedReceiverParameter/companionPure.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("infix.kt")
         public void testInfix() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/unusedReceiverParameter/infix.kt");
             doTest(fileName);
         }
 
+        @TestMetadata("object.kt")
+        public void testObject() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/unusedReceiverParameter/object.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("operator.kt")
         public void testOperator() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/unusedReceiverParameter/operator.kt");