Add quick-fix for type variance conflict #KT-23082 Fixed

idea/src/org/jetbrains/kotlin/idea/quickfix/QuickFixRegistrar.kt

@@ -553,5 +553,7 @@ class QuickFixRegistrar : QuickFixContributor {
         EXPERIMENTAL_OVERRIDE.registerFactory(ExperimentalFixesFactory)
         EXPERIMENTAL_OVERRIDE_ERROR.registerFactory(ExperimentalFixesFactory)
         EXPERIMENTAL_IS_NOT_ENABLED.registerFactory(MakeModuleExperimentalFix)
+
+        TYPE_VARIANCE_CONFLICT.registerFactory(RemoveTypeVarianceFix)
     }
 }

idea/src/org/jetbrains/kotlin/idea/quickfix/RemoveTypeVarianceFix.kt

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.idea.quickfix
+
+import com.intellij.openapi.editor.Editor
+import com.intellij.openapi.project.Project
+import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
+import org.jetbrains.kotlin.diagnostics.Diagnostic
+import org.jetbrains.kotlin.idea.caches.resolve.analyze
+import org.jetbrains.kotlin.idea.util.IdeDescriptorRenderers
+import org.jetbrains.kotlin.lexer.KtTokens
+import org.jetbrains.kotlin.psi.KtFile
+import org.jetbrains.kotlin.psi.KtTypeParameter
+import org.jetbrains.kotlin.psi.KtTypeReference
+import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
+import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
+import org.jetbrains.kotlin.types.Variance
+
+class RemoveTypeVarianceFix(
+    typeParameter: KtTypeParameter,
+    private val variance: Variance,
+    private val type: String
+) : KotlinQuickFixAction<KtTypeParameter>(typeParameter) {
+
+    override fun getText(): String = "Remove '${variance.label}' variance from '$type'"
+
+    override fun getFamilyName(): String = text
+
+    override fun invoke(project: Project, editor: Editor?, file: KtFile) {
+        val typeParameter = element ?: return
+        when (variance) {
+            Variance.IN_VARIANCE -> KtTokens.IN_KEYWORD
+            Variance.OUT_VARIANCE -> KtTokens.OUT_KEYWORD
+            else -> null
+        }?.let {
+            typeParameter.removeModifier(it)
+        }
+    }
+
+    companion object : KotlinSingleIntentionActionFactory() {
+        override fun createAction(diagnostic: Diagnostic): KotlinQuickFixAction<KtTypeParameter>? {
+            val typeReference = diagnostic.psiElement.parent as? KtTypeReference ?: return null
+            val type = typeReference.analyze(BodyResolveMode.PARTIAL)[BindingContext.TYPE, typeReference] ?: return null
+            val descriptor = type.constructor.declarationDescriptor as? TypeParameterDescriptor ?: return null
+            val variance = descriptor.variance
+            if (variance == Variance.INVARIANT) return null
+            val typeParameter = DescriptorToSourceUtils.getSourceFromDescriptor(descriptor) as? KtTypeParameter ?: return null
+            return RemoveTypeVarianceFix(typeParameter, variance, IdeDescriptorRenderers.SOURCE_CODE_TYPES.renderType(type))
+        }
+    }
+
+}

idea/testData/quickfix/removeTypeVariance/in.kt

@@ -0,0 +1,7 @@
+// "Remove 'in' variance from 'T'" "true"
+// WITH_RUNTIME
+
+class Test<in T> {
+    fun foo(t: T) {}
+    fun bar(): <caret>T = TODO()
+}

idea/testData/quickfix/removeTypeVariance/in.kt.after

@@ -0,0 +1,7 @@
+// "Remove 'in' variance from 'T'" "true"
+// WITH_RUNTIME
+
+class Test<T> {
+    fun foo(t: T) {}
+    fun bar(): <caret>T = TODO()
+}

idea/testData/quickfix/removeTypeVariance/out.kt

@@ -0,0 +1,7 @@
+// "Remove 'out' variance from 'T'" "true"
+// WITH_RUNTIME
+
+class Test<out T> {
+    fun foo(t: <caret>T) {}
+    fun bar(): T = TODO()
+}

idea/testData/quickfix/removeTypeVariance/out.kt.after

@@ -0,0 +1,7 @@
+// "Remove 'out' variance from 'T'" "true"
+// WITH_RUNTIME
+
+class Test<T> {
+    fun foo(t: <caret>T) {}
+    fun bar(): T = TODO()
+}

idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixMultiFileTestGenerated.java

@@ -3345,6 +3345,19 @@ public class QuickFixMultiFileTestGenerated extends AbstractQuickFixMultiFileTes
         }
     }
 
+    @TestMetadata("idea/testData/quickfix/removeTypeVariance")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class RemoveTypeVariance extends AbstractQuickFixMultiFileTest {
+        private void runTest(String testDataFilePath) throws Exception {
+            KotlinTestUtils.runTest(this::doTestWithExtraFile, TargetBackend.ANY, testDataFilePath);
+        }
+
+        public void testAllFilesPresentInRemoveTypeVariance() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/quickfix/removeTypeVariance"), Pattern.compile("^(\\w+)\\.((before\\.Main\\.\\w+)|(test))$"), TargetBackend.ANY, true);
+        }
+    }
+
     @TestMetadata("idea/testData/quickfix/removeUnused")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)

idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixTestGenerated.java

@@ -9065,6 +9065,29 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
         }
     }
 
+    @TestMetadata("idea/testData/quickfix/removeTypeVariance")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class RemoveTypeVariance extends AbstractQuickFixTest {
+        private void runTest(String testDataFilePath) throws Exception {
+            KotlinTestUtils.runTest(this::doTest, TargetBackend.ANY, testDataFilePath);
+        }
+
+        public void testAllFilesPresentInRemoveTypeVariance() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/quickfix/removeTypeVariance"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("in.kt")
+        public void testIn() throws Exception {
+            runTest("idea/testData/quickfix/removeTypeVariance/in.kt");
+        }
+
+        @TestMetadata("out.kt")
+        public void testOut() throws Exception {
+            runTest("idea/testData/quickfix/removeTypeVariance/out.kt");
+        }
+    }
+
     @TestMetadata("idea/testData/quickfix/removeUnused")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)