Introduce inspection for safe cast + return #KT-26230 Fixed

2018-08-21 18:32:21 +03:00
parent 2c71b3873e
commit 53c10238d6
20 changed files with 237 additions and 0 deletions
@@ -260,6 +260,13 @@ fun binaryExpressionVisitor(block: (KtBinaryExpression) -> Unit) =
        }
    }

+fun binaryWithTypeRHSExpressionVisitor(block: (KtBinaryExpressionWithTypeRHS) -> Unit) =
+    object : KtVisitorVoid() {
+        override fun visitBinaryWithTypeRHSExpression(expression: KtBinaryExpressionWithTypeRHS) {
+            block(expression)
+        }
+    }
+
 fun binaryExpressionRecursiveVisitor(block: (KtBinaryExpression) -> Unit) =
    object : KtTreeVisitorVoid() {
        override fun visitBinaryExpression(binaryExpression: KtBinaryExpression) {
@@ -0,0 +1,11 @@
+<html>
+<body>
+This inspection reports safe cast with 'return' should be replaced with 'if' type check. For example:
+<br /><br />
+<pre>
+fun test(x: Any) {
+    <b>x as? String ?: return</b> // Should be replaced with '<b>if (x !is String) return</b>'
+}
+</pre>
+</body>
+</html>
@@ -3048,6 +3048,15 @@ The Kotlin plugin provides language support in IntelliJ IDEA and Android Studio.
                     language="kotlin"
    />

+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.SafeCastWithReturnInspection"
+                     displayName="Safe cast with 'return' should be replaced with 'if' type check"
+                     groupPath="Kotlin"
+                     groupName="Style issues"
+                     enabledByDefault="true"
+                     level="WEAK WARNING"
+                     language="kotlin"
+    />
+
    <referenceImporter implementation="org.jetbrains.kotlin.idea.quickfix.KotlinReferenceImporter"/>

    <fileType.fileViewProviderFactory filetype="KJSM" implementationClass="com.intellij.psi.ClassFileViewProviderFactory"/>
@@ -3046,6 +3046,15 @@ The Kotlin plugin provides language support in IntelliJ IDEA and Android Studio.
                     language="kotlin"
    />

+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.SafeCastWithReturnInspection"
+                     displayName="Safe cast with 'return' should be replaced with 'if' type check"
+                     groupPath="Kotlin"
+                     groupName="Style issues"
+                     enabledByDefault="true"
+                     level="WEAK WARNING"
+                     language="kotlin"
+    />
+
    <referenceImporter implementation="org.jetbrains.kotlin.idea.quickfix.KotlinReferenceImporter"/>

    <fileType.fileViewProviderFactory filetype="KJSM" implementationClass="com.intellij.psi.ClassFileViewProviderFactory"/>
@@ -3047,6 +3047,15 @@ The Kotlin plugin provides language support in IntelliJ IDEA and Android Studio.
                     language="kotlin"
    />

+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.SafeCastWithReturnInspection"
+                     displayName="Safe cast with 'return' should be replaced with 'if' type check"
+                     groupPath="Kotlin"
+                     groupName="Style issues"
+                     enabledByDefault="true"
+                     level="WEAK WARNING"
+                     language="kotlin"
+    />
+
    <referenceImporter implementation="org.jetbrains.kotlin.idea.quickfix.KotlinReferenceImporter"/>

    <fileType.fileViewProviderFactory filetype="KJSM" implementationClass="com.intellij.psi.ClassFileViewProviderFactory"/>
@@ -3048,6 +3048,15 @@ The Kotlin plugin provides language support in IntelliJ IDEA and Android Studio.
                     language="kotlin"
    />

+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.SafeCastWithReturnInspection"
+                     displayName="Safe cast with 'return' should be replaced with 'if' type check"
+                     groupPath="Kotlin"
+                     groupName="Style issues"
+                     enabledByDefault="true"
+                     level="WEAK WARNING"
+                     language="kotlin"
+    />
+
    <referenceImporter implementation="org.jetbrains.kotlin.idea.quickfix.KotlinReferenceImporter"/>

    <fileType.fileViewProviderFactory filetype="KJSM" implementationClass="com.intellij.psi.ClassFileViewProviderFactory"/>
@@ -3046,6 +3046,15 @@ The Kotlin plugin provides language support in IntelliJ IDEA and Android Studio.
                     language="kotlin"
    />

+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.SafeCastWithReturnInspection"
+                     displayName="Safe cast with 'return' should be replaced with 'if' type check"
+                     groupPath="Kotlin"
+                     groupName="Style issues"
+                     enabledByDefault="true"
+                     level="WEAK WARNING"
+                     language="kotlin"
+    />
+
    <referenceImporter implementation="org.jetbrains.kotlin.idea.quickfix.KotlinReferenceImporter"/>

    <fileType.fileViewProviderFactory filetype="KJSM" implementationClass="com.intellij.psi.ClassFileViewProviderFactory"/>
@@ -3046,6 +3046,15 @@ The Kotlin plugin provides language support in IntelliJ IDEA and Android Studio.
                     language="kotlin"
    />

+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.SafeCastWithReturnInspection"
+                     displayName="Safe cast with 'return' should be replaced with 'if' type check"
+                     groupPath="Kotlin"
+                     groupName="Style issues"
+                     enabledByDefault="true"
+                     level="WEAK WARNING"
+                     language="kotlin"
+    />
+
    <referenceImporter implementation="org.jetbrains.kotlin.idea.quickfix.KotlinReferenceImporter"/>

    <fileType.fileViewProviderFactory filetype="KJSM" implementationClass="com.intellij.psi.ClassFileViewProviderFactory"/>
@@ -3048,6 +3048,15 @@ The Kotlin plugin provides language support in IntelliJ IDEA and Android Studio.
                     language="kotlin"
    />

+    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.SafeCastWithReturnInspection"
+                     displayName="Safe cast with 'return' should be replaced with 'if' type check"
+                     groupPath="Kotlin"
+                     groupName="Style issues"
+                     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 +1,64 @@
+/*
+ * Copyright 2010-2018 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.ProblemHighlightType
+import com.intellij.codeInspection.ProblemsHolder
+import com.intellij.openapi.project.Project
+import com.intellij.psi.PsiElementVisitor
+import org.jetbrains.kotlin.diagnostics.Errors
+import org.jetbrains.kotlin.idea.caches.resolve.analyze
+import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.psi.psiUtil.getStrictParentOfType
+import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
+
+class SafeCastWithReturnInspection : AbstractKotlinInspection() {
+    override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean): PsiElementVisitor =
+        binaryWithTypeRHSExpressionVisitor(fun(expression) {
+            if (expression.right == null) return
+            if (expression.operationReference.getReferencedName() != "as?") return
+
+            val parent = expression.getStrictParentOfType<KtBinaryExpression>() ?: return
+            if (KtPsiUtil.deparenthesize(parent.left) != expression) return
+            if (parent.operationReference.getReferencedName() != "?:") return
+            if (KtPsiUtil.deparenthesize(parent.right) !is KtReturnExpression) return
+
+            val context = expression.analyze(BodyResolveMode.PARTIAL_WITH_DIAGNOSTICS)
+            if (context[BindingContext.USED_AS_EXPRESSION, parent] == true) return
+            if (context.diagnostics.forElement(expression.operationReference).any { it.factory == Errors.CAST_NEVER_SUCCEEDS }) return
+
+            holder.registerProblem(
+                parent,
+                "Should be replaced with 'if' type check",
+                ProblemHighlightType.GENERIC_ERROR_OR_WARNING,
+                ReplaceWithIfFix()
+            )
+        })
+}
+
+private class ReplaceWithIfFix : LocalQuickFix {
+    override fun getName() = "Replace with 'if' type check"
+
+    override fun getFamilyName() = name
+
+    override fun applyFix(project: Project, descriptor: ProblemDescriptor) {
+        val elvisExpression = descriptor.psiElement as? KtBinaryExpression ?: return
+        val returnExpression = KtPsiUtil.deparenthesize(elvisExpression.right) ?: return
+        val safeCastExpression = KtPsiUtil.deparenthesize(elvisExpression.left) as? KtBinaryExpressionWithTypeRHS ?: return
+        val typeReference = safeCastExpression.right ?: return
+        elvisExpression.replace(
+            KtPsiFactory(elvisExpression).createExpressionByPattern(
+                "if ($0 !is $1) $2",
+                safeCastExpression.left,
+                typeReference,
+                returnExpression
+            )
+        )
+    }
+}
@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.inspections.SafeCastWithReturnInspection
@@ -0,0 +1,4 @@
+// PROBLEM: none
+fun test(x: Int) {
+    <caret>x as? String ?: return
+}
@@ -0,0 +1,6 @@
+fun test(x: Any): Int? {
+    <caret>(x as? String) ?: (return null)
+    return foo(x)
+}
+
+fun foo(x: String) = 1
@@ -0,0 +1,6 @@
+fun test(x: Any): Int? {
+    if (x !is String) return null
+    return foo(x)
+}
+
+fun foo(x: String) = 1
@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+fun test(list: List<Any>) {
+    list.mapNotNull {
+        it as? String ?: return@mapNotNull null<caret>
+        foo(it)
+    }
+}
+
+fun foo(x: String) = 1
@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+fun test(list: List<Any>) {
+    list.mapNotNull {
+        if (it !is String) return@mapNotNull null
+        foo(it)
+    }
+}
+
+fun foo(x: String) = 1
@@ -0,0 +1,6 @@
+fun test(x: Any): Int? {
+    <caret>x as? String ?: return null
+    return foo(x)
+}
+
+fun foo(x: String) = 1
@@ -0,0 +1,6 @@
+fun test(x: Any): Int? {
+    if (x !is String) return null
+    return foo(x)
+}
+
+fun foo(x: String) = 1
@@ -0,0 +1,7 @@
+// PROBLEM: none
+fun test(x: Any): Int? {
+    val s = <caret>x as? String ?: return null
+    return foo(s)
+}
+
+fun foo(x: String) = 1
@@ -5295,6 +5295,44 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
        }
    }

+    @TestMetadata("idea/testData/inspectionsLocal/safeCastWithReturn")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class SafeCastWithReturn extends AbstractLocalInspectionTest {
+        private void runTest(String testDataFilePath) throws Exception {
+            KotlinTestUtils.runTest(this::doTest, TargetBackend.ANY, testDataFilePath);
+        }
+
+        public void testAllFilesPresentInSafeCastWithReturn() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/inspectionsLocal/safeCastWithReturn"), Pattern.compile("^([\\w\\-_]+)\\.(kt|kts)$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("castNeverSucceeds.kt")
+        public void testCastNeverSucceeds() throws Exception {
+            runTest("idea/testData/inspectionsLocal/safeCastWithReturn/castNeverSucceeds.kt");
+        }
+
+        @TestMetadata("hasParenthesize.kt")
+        public void testHasParenthesize() throws Exception {
+            runTest("idea/testData/inspectionsLocal/safeCastWithReturn/hasParenthesize.kt");
+        }
+
+        @TestMetadata("labeledReturn.kt")
+        public void testLabeledReturn() throws Exception {
+            runTest("idea/testData/inspectionsLocal/safeCastWithReturn/labeledReturn.kt");
+        }
+
+        @TestMetadata("simple.kt")
+        public void testSimple() throws Exception {
+            runTest("idea/testData/inspectionsLocal/safeCastWithReturn/simple.kt");
+        }
+
+        @TestMetadata("usedAsExpression.kt")
+        public void testUsedAsExpression() throws Exception {
+            runTest("idea/testData/inspectionsLocal/safeCastWithReturn/usedAsExpression.kt");
+        }
+    }
+
    @TestMetadata("idea/testData/inspectionsLocal/scopeFunctions")
    @TestDataPath("$PROJECT_ROOT")
    @RunWith(JUnit3RunnerWithInners.class)
				`@@ -0,0 +1 @@`
				`org.jetbrains.kotlin.idea.inspections.SafeCastWithReturnInspection`