Add inspection to replace not-null assertion with elvis return

#KT-30381 Fixed
2019-03-12 12:05:00 +09:00
parent 1c0c01725b
commit dffcfdc02f
24 changed files with 282 additions and 0 deletions
@@ -3355,6 +3355,15 @@
                     language="kotlin"
    />
    <localInspection implementationClass="org.jetbrains.kotlin.idea.inspections.ReplaceNotNullAssertionWithElvisReturnInspection"
                     displayName="Replace '!!' with '?: return'"
                     groupPath="Kotlin"
                     groupName="Style issues"
                     enabledByDefault="false"
                     level="WEAK WARNING"
                     language="kotlin"
    />
    <referenceImporter implementation="org.jetbrains.kotlin.idea.quickfix.KotlinReferenceImporter"/>
    <fileType.fileViewProviderFactory filetype="KJSM" implementationClass="com.intellij.psi.ClassFileViewProviderFactory"/>
@@ -0,0 +1,13 @@
 <html>
 <body>
 This inspection reports not-null assertion (<b>!!</b>) calls that can be replaced with elvis and return (<b>?: return</b>). For example:
 <br /><br />
 <pre>
 val number: Int? = 42
 fun foo() {
    val a = number!! // Replace '!!' with '?: return'
    println(1 + a)
 }
 </pre>
 </body>
 </html>
@@ -0,0 +1,90 @@
 /*
 * 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.codeInsight.intention.LowPriorityAction
 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 org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.core.replaced
 import org.jetbrains.kotlin.idea.intentions.getParentLambdaLabelName
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.getParentOfTypes
 import org.jetbrains.kotlin.psi.psiUtil.getTopmostParentOfType
 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.isUnit
 class ReplaceNotNullAssertionWithElvisReturnInspection : AbstractKotlinInspection() {
    override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean) = postfixExpressionVisitor(fun(postfix) {
        if (postfix.baseExpression == null) return
        val operationReference = postfix.operationReference
        if (operationReference.getReferencedNameElementType() != KtTokens.EXCLEXCL) return
        if ((postfix.getTopmostParentOfType<KtParenthesizedExpression>() ?: postfix).parent is KtReturnExpression) return
        val parent = postfix.getParentOfTypes(true, KtLambdaExpression::class.java, KtNamedFunction::class.java)
        if (parent !is KtNamedFunction && parent !is KtLambdaExpression) return
        val context = postfix.analyze(BodyResolveMode.PARTIAL_WITH_DIAGNOSTICS)
        val (isNullable, returnLabelName) = when (parent) {
            is KtNamedFunction -> {
                val returnType = parent.descriptor(context)?.returnType ?: return
                val isNullable = returnType.isNullable()
                if (!returnType.isUnit() && !isNullable) return
                isNullable to null
            }
            is KtLambdaExpression -> {
                val functionLiteral = parent.functionLiteral
                val returnType = functionLiteral.descriptor(context)?.returnType ?: return
                if (!returnType.isUnit()) return
                val lambdaLabelName = functionLiteral.bodyBlockExpression?.getParentLambdaLabelName() ?: return
                false to lambdaLabelName
            }
            else -> return
        }
        if (context.diagnostics.forElement(operationReference).any { it.factory == Errors.UNNECESSARY_NOT_NULL_ASSERTION }) return
        holder.registerProblem(
            postfix.operationReference,
            "Replace '!!' with '?: return'",
            ProblemHighlightType.GENERIC_ERROR_OR_WARNING,
            ReplaceWithElvisReturnFix(isNullable, returnLabelName)
        )
    })
    private fun KtFunction.descriptor(context: BindingContext): FunctionDescriptor? {
        return context[BindingContext.DECLARATION_TO_DESCRIPTOR, this] as? FunctionDescriptor
    }
    private class ReplaceWithElvisReturnFix(
        private val returnNull: Boolean,
        private val returnLabelName: String?
    ) : LocalQuickFix, LowPriorityAction {
        override fun getName() = "Replace with '?: return${if (returnNull) " null" else ""}'"
        override fun getFamilyName() = name
        override fun applyFix(project: Project, descriptor: ProblemDescriptor) {
            val postfix = descriptor.psiElement.parent as? KtPostfixExpression ?: return
            val base = postfix.baseExpression ?: return
            val psiFactory = KtPsiFactory(postfix)
            postfix.replaced(
                psiFactory.createExpressionByPattern(
                    "$0 ?: return$1$2",
                    base,
                    returnLabelName?.let { "@$it" } ?: "",
                    if (returnNull) " null" else ""
                )
            )
        }
    }
 }
@@ -0,0 +1 @@
 org.jetbrains.kotlin.idea.inspections.ReplaceNotNullAssertionWithElvisReturnInspection
@@ -0,0 +1,3 @@
 fun test(i: Int?) {
    val x = i!!<caret>
 }
@@ -0,0 +1,3 @@
 fun test(i: Int?) {
    val x = i ?: return
 }
@@ -0,0 +1,5 @@
 fun foo(): Int? = null
 fun test() {
    foo()!!<caret>
 }
@@ -0,0 +1,5 @@
 fun foo(): Int? = null
 fun test() {
    foo() ?: return
 }
@@ -0,0 +1,6 @@
 class Foo(val i: Int?)
 fun test(foo: Foo): Int? {
    val x = foo.i!!<caret>
    return x
 }
@@ -0,0 +1,6 @@
 class Foo(val i: Int?)
 fun test(foo: Foo): Int? {
    val x = foo.i ?: return null
    return x
 }
@@ -0,0 +1,8 @@
 class Foo {
    fun baz(): Int? = null
 }
 fun test(foo: Foo): Int? {
    foo.baz()!!<caret>
    return 0
 }
@@ -0,0 +1,8 @@
 class Foo {
    fun baz(): Int? = null
 }
 fun test(foo: Foo): Int? {
    foo.baz() ?: return null
    return 0
 }
@@ -0,0 +1,3 @@
 fun test(i: Int?) {
    val x = i!!<caret> + 1
 }
@@ -0,0 +1,3 @@
 fun test(i: Int?) {
    val x = (i ?: return) + 1
 }
@@ -0,0 +1,6 @@
 // WITH_RUNTIME
 fun test(list: List<String>, number: Int?) {
    list.forEach {
        number!!<caret>
    }
 }
@@ -0,0 +1,6 @@
 // WITH_RUNTIME
 fun test(list: List<String>, number: Int?) {
    list.forEach {
        number ?: return@forEach
    }
 }
@@ -0,0 +1,7 @@
 // PROBLEM: none
 // WITH_RUNTIME
 fun test(list: List<String>, number: Int?) {
    val x: List<Int> = list.map {
        number!!<caret>
    }
 }
@@ -0,0 +1,5 @@
 // PROBLEM: none
 fun test(i: Int?): Int {
    val x = i!!<caret>
    return x
 }
@@ -0,0 +1,4 @@
 // PROBLEM: none
 fun test(i: Int?): Int? {
    return i!!<caret>
 }
@@ -0,0 +1,4 @@
 // PROBLEM: none
 fun test(i: Int?): Int? {
    return (i!!<caret>)
 }
@@ -0,0 +1,5 @@
 fun test(a: Int?): Int? {
    return check(a!!<caret>)
 }
 fun check(i: Int): Int = i
@@ -0,0 +1,5 @@
 fun test(a: Int?): Int? {
    return check(a ?: return null)
 }
 fun check(i: Int): Int = i
@@ -0,0 +1,4 @@
 // PROBLEM: none
 fun test(i: Int) {
    val x = i!!<caret>
 }
@@ -7117,6 +7117,79 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
        }
    }
    @TestMetadata("idea/testData/inspectionsLocal/replaceNotNullAssertionWithElvisReturn")
    @TestDataPath("$PROJECT_ROOT")
    @RunWith(JUnit3RunnerWithInners.class)
    public static class ReplaceNotNullAssertionWithElvisReturn extends AbstractLocalInspectionTest {
        private void runTest(String testDataFilePath) throws Exception {
            KotlinTestUtils.runTest(this::doTest, TargetBackend.ANY, testDataFilePath);
        }
        public void testAllFilesPresentInReplaceNotNullAssertionWithElvisReturn() throws Exception {
            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/inspectionsLocal/replaceNotNullAssertionWithElvisReturn"), Pattern.compile("^([\\w\\-_]+)\\.(kt|kts)$"), TargetBackend.ANY, true);
        }
        @TestMetadata("basic.kt")
        public void testBasic() throws Exception {
            runTest("idea/testData/inspectionsLocal/replaceNotNullAssertionWithElvisReturn/basic.kt");
        }
        @TestMetadata("basic2.kt")
        public void testBasic2() throws Exception {
            runTest("idea/testData/inspectionsLocal/replaceNotNullAssertionWithElvisReturn/basic2.kt");
        }
        @TestMetadata("basic3.kt")
        public void testBasic3() throws Exception {
            runTest("idea/testData/inspectionsLocal/replaceNotNullAssertionWithElvisReturn/basic3.kt");
        }
        @TestMetadata("basic4.kt")
        public void testBasic4() throws Exception {
            runTest("idea/testData/inspectionsLocal/replaceNotNullAssertionWithElvisReturn/basic4.kt");
        }
        @TestMetadata("basic5.kt")
        public void testBasic5() throws Exception {
            runTest("idea/testData/inspectionsLocal/replaceNotNullAssertionWithElvisReturn/basic5.kt");
        }
        @TestMetadata("inLambda.kt")
        public void testInLambda() throws Exception {
            runTest("idea/testData/inspectionsLocal/replaceNotNullAssertionWithElvisReturn/inLambda.kt");
        }
        @TestMetadata("inLambda2.kt")
        public void testInLambda2() throws Exception {
            runTest("idea/testData/inspectionsLocal/replaceNotNullAssertionWithElvisReturn/inLambda2.kt");
        }
        @TestMetadata("notNullFunction.kt")
        public void testNotNullFunction() throws Exception {
            runTest("idea/testData/inspectionsLocal/replaceNotNullAssertionWithElvisReturn/notNullFunction.kt");
        }
        @TestMetadata("onReturn.kt")
        public void testOnReturn() throws Exception {
            runTest("idea/testData/inspectionsLocal/replaceNotNullAssertionWithElvisReturn/onReturn.kt");
        }
        @TestMetadata("onReturn2.kt")
        public void testOnReturn2() throws Exception {
            runTest("idea/testData/inspectionsLocal/replaceNotNullAssertionWithElvisReturn/onReturn2.kt");
        }
        @TestMetadata("onReturn3.kt")
        public void testOnReturn3() throws Exception {
            runTest("idea/testData/inspectionsLocal/replaceNotNullAssertionWithElvisReturn/onReturn3.kt");
        }
        @TestMetadata("unnecessaryNotNullAssertion.kt")
        public void testUnnecessaryNotNullAssertion() throws Exception {
            runTest("idea/testData/inspectionsLocal/replaceNotNullAssertionWithElvisReturn/unnecessaryNotNullAssertion.kt");
        }
    }
    @TestMetadata("idea/testData/inspectionsLocal/replacePutWithAssignment")
    @TestDataPath("$PROJECT_ROOT")
    @RunWith(JUnit3RunnerWithInners.class)
		`@@ -0,0 +1 @@`
							`org.jetbrains.kotlin.idea.inspections.ReplaceNotNullAssertionWithElvisReturnInspection`