More correct algorithm for redundant type arguments detection

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/context/ResolutionContext.java

@@ -193,7 +193,9 @@ public abstract class ResolutionContext<Context extends ResolutionContext<Contex
 
     @Nullable
     public <T extends PsiElement> T getContextParentOfType(@NotNull KtExpression expression, @NotNull Class<? extends T>... classes) {
-        PsiElement current = expression.getParent();
+        KtExpression context = expressionContextProvider.invoke(expression);
+        PsiElement current = context != null ? context : expression.getParent();
+
         while (current != null) {
             for (Class<? extends T> klass : classes) {
                 if (klass.isInstance(current)) {
@@ -205,7 +207,7 @@ public abstract class ResolutionContext<Context extends ResolutionContext<Contex
             if (current instanceof PsiFile) return null;
 
             if (current instanceof KtExpression) {
-                KtExpression context = expressionContextProvider.invoke((KtExpression) current);
+                context = expressionContextProvider.invoke((KtExpression) current);
                 if (context != null) {
                     current = context;
                     continue;

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

@@ -18,17 +18,24 @@ package org.jetbrains.kotlin.idea.intentions
 
 import com.intellij.codeInspection.ProblemHighlightType
 import com.intellij.openapi.editor.Editor
+import com.intellij.openapi.util.Key
+import org.jetbrains.kotlin.descriptors.FunctionDescriptor
+import org.jetbrains.kotlin.descriptors.ValueDescriptor
+import org.jetbrains.kotlin.idea.analysis.analyzeInContext
 import org.jetbrains.kotlin.idea.caches.resolve.getResolutionFacade
+import org.jetbrains.kotlin.idea.core.copied
 import org.jetbrains.kotlin.idea.inspections.IntentionBasedInspection
-import org.jetbrains.kotlin.idea.resolve.frontendService
+import org.jetbrains.kotlin.idea.project.builtIns
 import org.jetbrains.kotlin.idea.util.getResolutionScope
 import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.psi.psiUtil.findDescendantOfType
+import org.jetbrains.kotlin.psi.psiUtil.getQualifiedExpressionForSelector
+import org.jetbrains.kotlin.psi.psiUtil.parentsWithSelf
 import org.jetbrains.kotlin.resolve.BindingContext
-import org.jetbrains.kotlin.resolve.BindingTraceContext
+import org.jetbrains.kotlin.resolve.DelegatingBindingTrace
 import org.jetbrains.kotlin.resolve.bindingContextUtil.getDataFlowInfoBefore
-import org.jetbrains.kotlin.resolve.calls.CallResolver
+import org.jetbrains.kotlin.resolve.bindingContextUtil.isUsedAsExpression
 import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
-import org.jetbrains.kotlin.resolve.calls.util.DelegatingCall
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.TypeUtils
@@ -73,29 +80,33 @@ class RemoveExplicitTypeArgumentsIntention : SelfTargetingOffsetIndependentInten
             if (callExpression.typeArguments.isEmpty()) return false
 
             val resolutionFacade = callExpression.getResolutionFacade()
-            val context = resolutionFacade.analyze(callExpression, BodyResolveMode.PARTIAL)
-            val calleeExpression = callExpression.calleeExpression ?: return false
-            val scope = calleeExpression.getResolutionScope(context, resolutionFacade)
-            val originalCall = callExpression.getResolvedCall(context) ?: return false
-            val untypedCall = CallWithoutTypeArgs(originalCall.call)
+            val bindingContext = resolutionFacade.analyze(callExpression, BodyResolveMode.PARTIAL)
+            val originalCall = callExpression.getResolvedCall(bindingContext) ?: return false
 
-            val expectedTypeIsExplicitInCode = callExpression.hasExplicitExpectedType(context)
-            val expectedType = if (expectedTypeIsExplicitInCode) {
-                context[BindingContext.EXPECTED_EXPRESSION_TYPE, callExpression] ?: TypeUtils.NO_EXPECTED_TYPE
-            }
-            else {
-                TypeUtils.NO_EXPECTED_TYPE
-            }
-            val dataFlow = context.getDataFlowInfoBefore(callExpression)
-            val callResolver = resolutionFacade.frontendService<CallResolver>()
-            val resolutionResults = callResolver.resolveFunctionCall(
-                    BindingTraceContext(), scope, untypedCall, expectedType, dataFlow, false)
-            if (!resolutionResults.isSingleResult) {
-                return false
-            }
+            val (contextExpression, expectedType) = findContextToAnalyze(callExpression, bindingContext)
+            val resolutionScope = contextExpression.getResolutionScope(bindingContext, resolutionFacade)
+
+            val key = Key<Unit>("RemoveExplicitTypeArgumentsIntention")
+            callExpression.putCopyableUserData(key, Unit)
+            val expressionToAnalyze = contextExpression.copied()
+            callExpression.putCopyableUserData(key, null)
+
+            val newCallExpression = expressionToAnalyze.findDescendantOfType<KtCallExpression> { it.getCopyableUserData(key) != null }!!
+            newCallExpression.typeArgumentList!!.delete()
+
+            val newBindingContext = expressionToAnalyze.analyzeInContext(
+                    resolutionScope,
+                    contextExpression,
+                    trace = DelegatingBindingTrace(bindingContext, "Temporary trace"),
+                    dataFlowInfo = bindingContext.getDataFlowInfoBefore(contextExpression),
+                    expectedType = expectedType ?: TypeUtils.NO_EXPECTED_TYPE,
+                    isStatement = expectedType == null
+            )
+
+            val newCall = newCallExpression.getResolvedCall(newBindingContext) ?: return false
 
             val args = originalCall.typeArguments
-            val newArgs = resolutionResults.resultingCall.typeArguments
+            val newArgs = newCall.typeArguments
 
             fun equalTypes(type1: KotlinType, type2: KotlinType): Boolean {
                 return if (approximateFlexible) {
@@ -110,17 +121,61 @@ class RemoveExplicitTypeArgumentsIntention : SelfTargetingOffsetIndependentInten
                 equalTypes(argType, newArgType)
             }
         }
+
+        private fun findContextToAnalyze(expression: KtExpression, bindingContext: BindingContext): Pair<KtExpression, KotlinType?> {
+            for (element in expression.parentsWithSelf) {
+                if (element !is KtExpression) continue
+
+                if (element.getQualifiedExpressionForSelector() != null) continue
+                if (!element.isUsedAsExpression(bindingContext)) return element to null
+
+                val parent = element.parent
+                when (parent) {
+                    is KtNamedFunction -> {
+                        val expectedType = if (element == parent.bodyExpression && !parent.hasBlockBody() && parent.hasDeclaredReturnType())
+                            (bindingContext[BindingContext.DECLARATION_TO_DESCRIPTOR, parent] as? FunctionDescriptor)?.returnType
+                        else
+                            null
+                        return element to expectedType
+                    }
+
+                    is KtVariableDeclaration -> {
+                        val expectedType = if (element == parent.initializer && parent.typeReference != null)
+                            (bindingContext[BindingContext.DECLARATION_TO_DESCRIPTOR, parent] as? ValueDescriptor)?.type
+                        else
+                            null
+                        return element to expectedType
+                    }
+
+                    is KtParameter -> {
+                        val expectedType = if (element == parent.defaultValue)
+                            (bindingContext[BindingContext.DECLARATION_TO_DESCRIPTOR, parent] as? ValueDescriptor)?.type
+                        else
+                            null
+                        return element to expectedType
+                    }
+
+                    is KtPropertyAccessor -> {
+                        val property = parent.parent as KtProperty
+                        val expectedType = when {
+                            element != parent.bodyExpression || parent.hasBlockBody() -> null
+                            parent.isSetter -> parent.builtIns.unitType
+                            property.typeReference == null -> null
+                            else -> (bindingContext[BindingContext.DECLARATION_TO_DESCRIPTOR, parent] as? FunctionDescriptor)?.returnType
+                        }
+                        return element to expectedType
+                    }
+                }
+            }
+
+            return expression to null
+        }
     }
 
     override fun isApplicableTo(element: KtTypeArgumentList): Boolean {
         return isApplicableTo(element, approximateFlexible = false)
     }
 
-    private class CallWithoutTypeArgs(call: Call) : DelegatingCall(call) {
-        override fun getTypeArguments() = emptyList<KtTypeProjection>()
-        override fun getTypeArgumentList() = null
-    }
-
     override fun applyTo(element: KtTypeArgumentList, editor: Editor?) {
         element.delete()
     }

idea/testData/intentions/removeExplicitTypeArguments/blockValue.kt

@@ -0,0 +1,12 @@
+// IS_APPLICABLE: true
+// WITH_RUNTIME
+
+fun f(p: Int): List<String>? {
+    return if (p > 0) {
+        print("a")
+        listOf<caret><String>()
+    }
+    else {
+        null
+    }
+}

idea/testData/intentions/removeExplicitTypeArguments/blockValue.kt.after

@@ -0,0 +1,12 @@
+// IS_APPLICABLE: true
+// WITH_RUNTIME
+
+fun f(p: Int): List<String>? {
+    return if (p > 0) {
+        print("a")
+        listOf()
+    }
+    else {
+        null
+    }
+}

idea/testData/intentions/removeExplicitTypeArguments/defaultParamValue.kt

@@ -0,0 +1,5 @@
+// IS_APPLICABLE: true
+// WITH_RUNTIME
+
+fun foo(p: List<String> = listOf<caret><String>()) {
+}

idea/testData/intentions/removeExplicitTypeArguments/defaultParamValue.kt.after

@@ -0,0 +1,5 @@
+// IS_APPLICABLE: true
+// WITH_RUNTIME
+
+fun foo(p: List<String> = listOf()) {
+}

idea/testData/intentions/removeExplicitTypeArguments/getterBody.kt

@@ -0,0 +1,5 @@
+// IS_APPLICABLE: true
+// WITH_RUNTIME
+
+val x: List<String>
+    get() = listOf<caret><String>()

idea/testData/intentions/removeExplicitTypeArguments/getterBody.kt.after

@@ -0,0 +1,5 @@
+// IS_APPLICABLE: true
+// WITH_RUNTIME
+
+val x: List<String>
+    get() = listOf()

idea/testData/intentions/removeExplicitTypeArguments/inspectionData/expected.xml

@@ -138,7 +138,7 @@
     <file>insideOtherCall.kt</file>
     <line>5</line>
     <module>light_idea_test_case</module>
-    <entry_point TYPE="file" FQNAME="temp:///src/insideOtherCall.kt" />
+    <entry_point TYPE="file" FQNAME="insideOtherCall.kt" />
     <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Unnecessary type argument</problem_class>
     <description>Remove explicit type arguments</description>
   </problem>
@@ -147,7 +147,7 @@
     <file>insideDeepOtherCall.kt</file>
     <line>8</line>
     <module>light_idea_test_case</module>
-    <entry_point TYPE="file" FQNAME="temp:///src/insideDeepOtherCall.kt" />
+    <entry_point TYPE="file" FQNAME="insideDeepOtherCall.kt" />
     <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Unnecessary type argument</problem_class>
     <description>Remove explicit type arguments</description>
   </problem>
@@ -156,9 +156,62 @@
     <file>insideDeepOtherCall.kt</file>
     <line>8</line>
     <module>light_idea_test_case</module>
-    <entry_point TYPE="file" FQNAME="temp:///src/insideDeepOtherCall.kt" />
+    <entry_point TYPE="file" FQNAME="insideDeepOtherCall.kt" />
     <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Unnecessary type argument</problem_class>
     <description>Remove explicit type arguments</description>
   </problem>
 
+  <problem>
+    <file>twoArguments.kt</file>
+    <line>8</line>
+    <module>light_idea_test_case</module>
+    <entry_point TYPE="file" FQNAME="twoArguments.kt" />
+    <problem_class severity="WARNING" attribute_key="NOT_USED_ELEMENT_ATTRIBUTES">Unnecessary type argument</problem_class>
+    <description>Remove explicit type arguments</description>
+  </problem>
+
+  <problem>
+    <file>twoArguments.kt</file>
+    <line>8</line>
+    <module>light_idea_test_case</module>
+    <entry_point TYPE="file" FQNAME="twoArguments.kt" />
+    <problem_class severity="WARNING" attribute_key="NOT_USED_ELEMENT_ATTRIBUTES">Unnecessary type argument</problem_class>
+    <description>Remove explicit type arguments</description>
+  </problem>
+
+  <problem>
+    <file>qualified.kt</file>
+    <line>6</line>
+    <module>light_idea_test_case</module>
+    <entry_point TYPE="file" FQNAME="qualified.kt" />
+    <problem_class severity="WARNING" attribute_key="NOT_USED_ELEMENT_ATTRIBUTES">Unnecessary type argument</problem_class>
+    <description>Remove explicit type arguments</description>
+  </problem>
+
+  <problem>
+    <file>getterBody.kt</file>
+    <line>5</line>
+    <module>light_idea_test_case</module>
+    <entry_point TYPE="file" FQNAME="getterBody.kt" />
+    <problem_class severity="WARNING" attribute_key="NOT_USED_ELEMENT_ATTRIBUTES">Unnecessary type argument</problem_class>
+    <description>Remove explicit type arguments</description>
+  </problem>
+
+  <problem>
+    <file>defaultParamValue.kt</file>
+    <line>4</line>
+    <module>light_idea_test_case</module>
+    <entry_point TYPE="file" FQNAME="defaultParamValue.kt" />
+    <problem_class severity="WARNING" attribute_key="NOT_USED_ELEMENT_ATTRIBUTES">Unnecessary type argument</problem_class>
+    <description>Remove explicit type arguments</description>
+  </problem>
+
+  <problem>
+    <file>blockValue.kt</file>
+    <line>7</line>
+    <module>light_idea_test_case</module>
+    <entry_point TYPE="file" FQNAME="blockValue.kt" />
+    <problem_class severity="WARNING" attribute_key="NOT_USED_ELEMENT_ATTRIBUTES">Unnecessary type argument</problem_class>
+    <description>Remove explicit type arguments</description>
+  </problem>
 </problems>

idea/testData/intentions/removeExplicitTypeArguments/qualified.kt

@@ -0,0 +1,7 @@
+interface I<T>
+
+fun <T> Int.foo(p: I<T>){}
+
+fun bar(p: I<String>) {
+    1.foo<caret><String>(p)
+}

idea/testData/intentions/removeExplicitTypeArguments/qualified.kt.after

@@ -0,0 +1,7 @@
+interface I<T>
+
+fun <T> Int.foo(p: I<T>){}
+
+fun bar(p: I<String>) {
+    1.foo(p)
+}

idea/testData/intentions/removeExplicitTypeArguments/twoArguments.kt

@@ -0,0 +1,9 @@
+// IS_APPLICABLE: true
+// WITH_RUNTIME
+
+fun <T> foo(p1: List<T>, p2: List<T>) {
+}
+
+fun bar() {
+    foo(listOf<caret><String>(), listOf<String>())
+}

idea/testData/intentions/removeExplicitTypeArguments/twoArguments.kt.after

@@ -0,0 +1,9 @@
+// IS_APPLICABLE: true
+// WITH_RUNTIME
+
+fun <T> foo(p1: List<T>, p2: List<T>) {
+}
+
+fun bar() {
+    foo(listOf(), listOf<String>())
+}

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

@@ -12896,6 +12896,18 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/intentions/removeExplicitTypeArguments"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), TargetBackend.ANY, true);
         }
 
+        @TestMetadata("blockValue.kt")
+        public void testBlockValue() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/removeExplicitTypeArguments/blockValue.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("defaultParamValue.kt")
+        public void testDefaultParamValue() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/removeExplicitTypeArguments/defaultParamValue.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("fourLiterals.kt")
         public void testFourLiterals() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/removeExplicitTypeArguments/fourLiterals.kt");
@@ -12908,6 +12920,12 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             doTest(fileName);
         }
 
+        @TestMetadata("getterBody.kt")
+        public void testGetterBody() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/removeExplicitTypeArguments/getterBody.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("inapplicableTypeThatIsAFunItCannotBeInferred.kt")
         public void testInapplicableTypeThatIsAFunItCannotBeInferred() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/removeExplicitTypeArguments/inapplicableTypeThatIsAFunItCannotBeInferred.kt");
@@ -13010,12 +13028,24 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             doTest(fileName);
         }
 
+        @TestMetadata("qualified.kt")
+        public void testQualified() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/removeExplicitTypeArguments/qualified.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("returnCallWithUnnecessaryTypeArgs.kt")
         public void testReturnCallWithUnnecessaryTypeArgs() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/removeExplicitTypeArguments/returnCallWithUnnecessaryTypeArgs.kt");
             doTest(fileName);
         }
 
+        @TestMetadata("twoArguments.kt")
+        public void testTwoArguments() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/removeExplicitTypeArguments/twoArguments.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("twoLiteralValues.kt")
         public void testTwoLiteralValues() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/removeExplicitTypeArguments/twoLiteralValues.kt");

j2k/testData/fileOrElement/field/specifyType.kt

@@ -20,7 +20,7 @@ internal class A {
     }
 
     fun bar() {
-        field5 = ArrayList<String>()
+        field5 = ArrayList()
         field7++
         field8++
         field9 = null