Implement inspection for redundant lambda arrow

Fixes #KT-11991
2017-07-22 17:10:19 +02:00
parent 9ac1a0140c
commit 41e5840298
8 changed files with 108 additions and 0 deletions
@@ -0,0 +1,5 @@
+<html>
+<body>
+This inspection reports lambdas without parameters that use the lambda arrow.
+</body>
+</html>
@@ -2446,6 +2446,15 @@
                     language="kotlin"
    />

+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.RedundantLambdaArrowInspection"
+                     displayName="Redundant lambda arrow"
+                     groupPath="Kotlin"
+                     groupName="Redundant constructs"
+                     enabledByDefault="true"
+                     level="WEAK WARNING"
+                     language="kotlin"
+    />
+
    <referenceImporter implementation="org.jetbrains.kotlin.idea.quickfix.KotlinReferenceImporter"/>

    <fileType.fileViewProviderFactory filetype="KJSM" implementationClass="com.intellij.psi.ClassFileViewProviderFactory"/>
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.idea.inspections
+
+import com.intellij.codeInsight.FileModificationService
+import com.intellij.codeInspection.LocalQuickFix
+import com.intellij.codeInspection.ProblemDescriptor
+import com.intellij.codeInspection.ProblemHighlightType
+import com.intellij.codeInspection.ProblemsHolder
+import com.intellij.openapi.project.Project
+import com.intellij.psi.PsiElementVisitor
+import org.jetbrains.kotlin.psi.KtLambdaExpression
+import org.jetbrains.kotlin.psi.KtVisitorVoid
+
+class RedundantLambdaArrowInspection : AbstractKotlinInspection() {
+    override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean): PsiElementVisitor {
+        return object : KtVisitorVoid() {
+            override fun visitLambdaExpression(lambdaExpression: KtLambdaExpression) {
+                val functionLiteral = lambdaExpression.functionLiteral
+                if (functionLiteral.valueParameters.isNotEmpty()) return
+                val arrow = functionLiteral.arrow ?: return
+
+                holder.registerProblem(
+                        arrow,
+                        "Redundant lambda arrow",
+                        ProblemHighlightType.LIKE_UNUSED_SYMBOL,
+                        DeleteFix())
+            }
+        }
+    }
+
+    class DeleteFix : LocalQuickFix {
+        override fun getFamilyName() = "Remove arrow"
+
+        override fun applyFix(project: Project, descriptor: ProblemDescriptor) {
+            val element = descriptor.psiElement
+            FileModificationService.getInstance().preparePsiElementForWrite(element)
+            element.delete()
+        }
+    }
+}
@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.inspections.RedundantLambdaArrowInspection
@@ -0,0 +1,7 @@
+// PROBLEM: none
+
+fun foo(f: (Int) -> Unit) {}
+
+fun bar() {
+    foo { i <caret>-> }
+}
@@ -0,0 +1,5 @@
+fun foo(f: () -> Unit) {}
+
+fun bar() {
+    foo { <caret>-> }
+}
@@ -0,0 +1,5 @@
+fun foo(f: () -> Unit) {}
+
+fun bar() {
+    foo { <caret>}
+}
@@ -1305,6 +1305,27 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
        }
    }

+    @TestMetadata("idea/testData/inspectionsLocal/redundantLambdaArrow")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class RedundantLambdaArrow extends AbstractLocalInspectionTest {
+        public void testAllFilesPresentInRedundantLambdaArrow() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/inspectionsLocal/redundantLambdaArrow"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("hasArguments.kt")
+        public void testHasArguments() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/redundantLambdaArrow/hasArguments.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("simple.kt")
+        public void testSimple() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/redundantLambdaArrow/simple.kt");
+            doTest(fileName);
+        }
+    }
+
    @TestMetadata("idea/testData/inspectionsLocal/removeRedundantSpreadOperator")
    @TestDataPath("$PROJECT_ROOT")
    @RunWith(JUnit3RunnerWithInners.class)
				`@@ -0,0 +1 @@`
				`org.jetbrains.kotlin.idea.inspections.RedundantLambdaArrowInspection`