Add inspection for equals which is called recursively within itself

So #KT-13702 Fixed
2017-11-09 17:24:30 +03:00
parent bd348911af
commit b8fcdea673
7 changed files with 132 additions and 0 deletions
@@ -0,0 +1,20 @@
+<html>
+<body>
+Reports recursive equals calls.
+
+<p>
+For example:
+<code>
+<pre>
+class X {
+    override fun equals(other: Any?): Boolean {
+        if (this == other) return true // recursive equals call
+        return false
+    }
+}
+</pre>
+</code>
+</p>
+
+</body>
+</html>
@@ -2672,6 +2672,15 @@
    />


+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.RecursiveEqualsCallInspection"
+                     displayName="Recursive equals call"
+                     groupPath="Kotlin"
+                     groupName="Probable bugs"
+                     enabledByDefault="true"
+                     level="WARNING"
+                     language="kotlin"
+    />
+
    <referenceImporter implementation="org.jetbrains.kotlin.idea.quickfix.KotlinReferenceImporter"/>

    <fileType.fileViewProviderFactory filetype="KJSM" implementationClass="com.intellij.psi.ClassFileViewProviderFactory"/>
@@ -0,0 +1,75 @@
+/*
+ * 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 com.intellij.psi.PsiElementVisitor
+import org.jetbrains.kotlin.descriptors.FunctionDescriptor
+import org.jetbrains.kotlin.idea.caches.resolve.analyze
+import org.jetbrains.kotlin.idea.search.usagesSearch.descriptor
+import org.jetbrains.kotlin.lexer.KtTokens
+import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.psi.psiUtil.containingClass
+import org.jetbrains.kotlin.psi.psiUtil.getNonStrictParentOfType
+import org.jetbrains.kotlin.resolve.DescriptorUtils
+import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
+import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
+import org.jetbrains.kotlin.types.typeUtil.isBoolean
+import org.jetbrains.kotlin.types.typeUtil.isNullableAny
+
+class RecursiveEqualsCallInspection : AbstractKotlinInspection() {
+    override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean, session: LocalInspectionToolSession): PsiElementVisitor {
+        return object : KtVisitorVoid() {
+
+            override fun visitBinaryExpression(expr: KtBinaryExpression) {
+                super.visitBinaryExpression(expr)
+
+                if (expr.operationToken != KtTokens.EQEQ) return
+
+                val classDescriptor = expr.containingClass()?.descriptor ?: return
+                val context = expr.analyze(BodyResolveMode.PARTIAL)
+                if (classDescriptor != expr.getResolvedCall(context)?.dispatchReceiver?.type?.constructor?.declarationDescriptor) return
+
+                val functionDescriptor = expr.getNonStrictParentOfType<KtNamedFunction>()?.descriptor as? FunctionDescriptor ?: return
+                if (functionDescriptor.name.asString() != "equals" ||
+                    !DescriptorUtils.isOverride(functionDescriptor) ||
+                    functionDescriptor.valueParameters.singleOrNull()?.type?.isNullableAny() == false ||
+                    functionDescriptor.returnType?.isBoolean() == false) return
+
+                holder.registerProblem(expr,
+                                       "Recursive equals call",
+                                       ProblemHighlightType.GENERIC_ERROR_OR_WARNING,
+                                       ReplaceWithReferentialEqualityFix())
+            }
+        }
+    }
+}
+
+private class ReplaceWithReferentialEqualityFix : LocalQuickFix {
+    override fun getName() = "Replace with '==='"
+
+    override fun getFamilyName() = name
+
+    override fun applyFix(project: Project, descriptor: ProblemDescriptor) {
+        val expr = descriptor.psiElement as? KtBinaryExpression ?: return
+        val left = expr.left ?: return
+        val right = expr.right ?: return
+        expr.replace(KtPsiFactory(project).createExpressionByPattern("$0 $1 $2", left, "===", right))
+    }
+}
+
@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.inspections.RecursiveEqualsCallInspection
@@ -0,0 +1,6 @@
+class Test {
+    override fun equals(other: Any?): Boolean {
+        if (<caret>this == other) return true
+        return false
+    }
+}
@@ -0,0 +1,6 @@
+class Test {
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        return false
+    }
+}
@@ -1500,6 +1500,21 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
        }
    }

+    @TestMetadata("idea/testData/inspectionsLocal/recursiveEqualsCall")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class RecursiveEqualsCall extends AbstractLocalInspectionTest {
+        public void testAllFilesPresentInRecursiveEqualsCall() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/inspectionsLocal/recursiveEqualsCall"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("recursive.kt")
+        public void testRecursive() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspectionsLocal/recursiveEqualsCall/recursive.kt");
+            doTest(fileName);
+        }
+    }
+
    @TestMetadata("idea/testData/inspectionsLocal/redundantExplicitType")
    @TestDataPath("$PROJECT_ROOT")
    @RunWith(JUnit3RunnerWithInners.class)
				`@@ -0,0 +1 @@`
				`org.jetbrains.kotlin.idea.inspections.RecursiveEqualsCallInspection`