Introduce "double negation" inspection #KT-4748 Fixed

2017-07-25 13:08:27 +03:00
parent be0b01a1e6
commit 88fa7c2952
12 changed files with 140 additions and 0 deletions
@@ -0,0 +1,5 @@
+<html>
+<body>
+This inspection reports redundant double negation usages, like <code>val truth = !!true</code>
+</body>
+</html>
@@ -2428,6 +2428,15 @@
                     language="kotlin"
    />

+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.KotlinDoubleNegationInspection"
+                     displayName="Redundant double negation"
+                     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 +1,69 @@
+/*
+ * 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.codeInspection.*
+import com.intellij.openapi.project.Project
+import org.jetbrains.kotlin.idea.caches.resolve.analyze
+import org.jetbrains.kotlin.idea.core.replaced
+import org.jetbrains.kotlin.lexer.KtTokens
+import org.jetbrains.kotlin.psi.KtParenthesizedExpression
+import org.jetbrains.kotlin.psi.KtPrefixExpression
+import org.jetbrains.kotlin.psi.KtVisitorVoid
+import org.jetbrains.kotlin.resolve.calls.callUtil.getType
+import org.jetbrains.kotlin.types.typeUtil.isBoolean
+
+class KotlinDoubleNegationInspection : AbstractKotlinInspection(), CleanupLocalInspectionTool {
+    override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean, session: LocalInspectionToolSession) =
+            object : KtVisitorVoid() {
+                override fun visitPrefixExpression(expression: KtPrefixExpression) {
+                    if (expression.operationToken != KtTokens.EXCL ||
+                        expression.baseExpression?.getType(expression.analyze())?.isBoolean() != true) {
+                        return
+                    }
+                    var parent = expression.parent
+                    while (parent is KtParenthesizedExpression) {
+                        parent = parent.parent
+                    }
+                    if (parent is KtPrefixExpression && parent.operationToken == KtTokens.EXCL) {
+                        holder.registerProblem(expression,
+                                               "Redundant double negation",
+                                               ProblemHighlightType.GENERIC_ERROR_OR_WARNING,
+                                               DoubleNegationFix())
+                    }
+                }
+            }
+
+    private class DoubleNegationFix : LocalQuickFix {
+        override fun getName() = "Remove redundant negations"
+        override fun getFamilyName() = name
+
+        override fun applyFix(project: Project, descriptor: ProblemDescriptor) {
+            applyFix(descriptor.psiElement as? KtPrefixExpression ?: return)
+        }
+
+        private fun applyFix(expression: KtPrefixExpression) {
+            var parent = expression.parent
+            while (parent is KtParenthesizedExpression) {
+                parent = parent.parent
+            }
+            if (parent is KtPrefixExpression && parent.operationToken == KtTokens.EXCL) {
+                expression.baseExpression?.let { parent.replaced(it) }
+            }
+        }
+    }
+}
@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.inspections.KotlinDoubleNegationInspection
@@ -0,0 +1,3 @@
+fun foo() {
+    val b = !!<caret>"".equals("")
+}
@@ -0,0 +1,3 @@
+fun foo() {
+    val b = "".equals("")
+}
@@ -0,0 +1,5 @@
+// PROBLEM: none
+operator fun Int.not() = this * -1
+fun foo() {
+    val c = !!<caret>1
+}
@@ -0,0 +1,3 @@
+fun foo() {
+    val b = !(!<caret>true)
+}
@@ -0,0 +1,3 @@
+fun foo() {
+    val b = true
+}
@@ -0,0 +1,3 @@
+fun foo() {
+    val b = !!<caret>true
+}
@@ -0,0 +1,3 @@
+fun foo() {
+    val b = true
+}
@@ -492,6 +492,39 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
        }
    }

+    @TestMetadata("idea/testData/inspectionsLocal/doubleNegation")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class DoubleNegation extends AbstractLocalInspectionTest {
+        public void testAllFilesPresentInDoubleNegation() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/inspectionsLocal/doubleNegation"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("function.kt")
+        public void testFunction() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/doubleNegation/function.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("invalid.kt")
+        public void testInvalid() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/doubleNegation/invalid.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("parenthesized.kt")
+        public void testParenthesized() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/doubleNegation/parenthesized.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("simple.kt")
+        public void testSimple() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/doubleNegation/simple.kt");
+            doTest(fileName);
+        }
+    }
+
    @TestMetadata("idea/testData/inspectionsLocal/emptyRange")
    @TestDataPath("$PROJECT_ROOT")
    @RunWith(JUnit3RunnerWithInners.class)
				`@@ -0,0 +1 @@`
				`org.jetbrains.kotlin.idea.inspections.KotlinDoubleNegationInspection`