Add "Constructor has non-null self reference parameter" inspection (KT-29799)

#KT-29799 Fixed
2019-03-07 11:46:35 +03:00
parent 6634d7ab15
commit bcfab83d1c
8 changed files with 104 additions and 0 deletions
@@ -3364,6 +3364,15 @@
                     language="kotlin"
    />

+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.SelfReferenceConstructorParameterInspection"
+                     displayName="Constructor has non-null self reference parameter"
+                     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 +1,5 @@
+<html>
+<body>
+This inspection reports constructor that has a non-null self reference parameter. A class with such a constructor can never be instantiated.
+</body>
+</html>
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2010-2019 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.inspections
+
+import com.intellij.codeInspection.LocalQuickFix
+import com.intellij.codeInspection.ProblemDescriptor
+import com.intellij.codeInspection.ProblemsHolder
+import com.intellij.openapi.project.Project
+import org.jetbrains.kotlin.idea.caches.resolve.analyze
+import org.jetbrains.kotlin.idea.core.setType
+import org.jetbrains.kotlin.psi.KtParameter
+import org.jetbrains.kotlin.psi.KtParameterList
+import org.jetbrains.kotlin.psi.primaryConstructorVisitor
+import org.jetbrains.kotlin.psi.psiUtil.containingClass
+import org.jetbrains.kotlin.psi.psiUtil.startOffset
+import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
+import org.jetbrains.kotlin.types.isNullable
+import org.jetbrains.kotlin.types.typeUtil.makeNullable
+
+class SelfReferenceConstructorParameterInspection : AbstractKotlinInspection() {
+    override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean) = primaryConstructorVisitor(fun(constructor) {
+        val parameter = constructor.valueParameterList?.selfReferenceParameter() ?: return
+        val rangeInElement = parameter.typeReference?.textRange?.shiftRight(-parameter.startOffset) ?: return
+        holder.registerProblem(
+            parameter,
+            rangeInElement,
+            "Constructor has non-null self reference parameter",
+            ConvertToNullableTypeFix()
+        )
+    })
+
+    private fun KtParameterList.selfReferenceParameter(): KtParameter? {
+        val containingClass = this.containingClass() ?: return null
+        val className = containingClass.name ?: return null
+        val parameter = this.parameters.firstOrNull { it.typeReference?.text == className } ?: return null
+
+        val typeReference = parameter.typeReference ?: return null
+        val context = analyze(BodyResolveMode.PARTIAL)
+        val type = context[BindingContext.TYPE, typeReference] ?: return null
+        if (type.isNullable()) return null
+        if (type.constructor.declarationDescriptor != context[BindingContext.DECLARATION_TO_DESCRIPTOR, containingClass]) return null
+
+        return parameter
+    }
+
+    private class ConvertToNullableTypeFix : LocalQuickFix {
+        override fun getName() = "Convert to nullable type"
+
+        override fun getFamilyName() = name
+
+        override fun applyFix(project: Project, descriptor: ProblemDescriptor) {
+            val parameter = descriptor.psiElement as? KtParameter ?: return
+            val typeReference = parameter.typeReference ?: return
+            val type = parameter.analyze(BodyResolveMode.PARTIAL)[BindingContext.TYPE, typeReference] ?: return
+            parameter.setType(type.makeNullable())
+        }
+    }
+}
@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.inspections.SelfReferenceConstructorParameterInspection
@@ -0,0 +1 @@
+class SelfRef(val ref: SelfRef<caret>)
@@ -0,0 +1 @@
+class SelfRef(val ref: SelfRef?)
@@ -0,0 +1,2 @@
+// PROBLEM: none
+class SelfRef(val ref: <caret>SelfRef?)
@@ -7917,6 +7917,29 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
        }
    }

+    @TestMetadata("idea/testData/inspectionsLocal/selfReferenceConstructorParameter")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class SelfReferenceConstructorParameter extends AbstractLocalInspectionTest {
+        private void runTest(String testDataFilePath) throws Exception {
+            KotlinTestUtils.runTest(this::doTest, TargetBackend.ANY, testDataFilePath);
+        }
+
+        public void testAllFilesPresentInSelfReferenceConstructorParameter() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/inspectionsLocal/selfReferenceConstructorParameter"), Pattern.compile("^([\\w\\-_]+)\\.(kt|kts)$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("basic.kt")
+        public void testBasic() throws Exception {
+            runTest("idea/testData/inspectionsLocal/selfReferenceConstructorParameter/basic.kt");
+        }
+
+        @TestMetadata("nullable.kt")
+        public void testNullable() throws Exception {
+            runTest("idea/testData/inspectionsLocal/selfReferenceConstructorParameter/nullable.kt");
+        }
+    }
+
    @TestMetadata("idea/testData/inspectionsLocal/setterBackingFieldAssignment")
    @TestDataPath("$PROJECT_ROOT")
    @RunWith(JUnit3RunnerWithInners.class)
				`@@ -0,0 +1 @@`
				`org.jetbrains.kotlin.idea.inspections.SelfReferenceConstructorParameterInspection`