/
NoNameShadowing.kt
102 lines (94 loc) · 3.61 KB
/
NoNameShadowing.kt
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package io.gitlab.arturbosch.detekt.rules.naming
import io.gitlab.arturbosch.detekt.api.CodeSmell
import io.gitlab.arturbosch.detekt.api.Config
import io.gitlab.arturbosch.detekt.api.Debt
import io.gitlab.arturbosch.detekt.api.Entity
import io.gitlab.arturbosch.detekt.api.Issue
import io.gitlab.arturbosch.detekt.api.Rule
import io.gitlab.arturbosch.detekt.api.Severity
import io.gitlab.arturbosch.detekt.api.internal.ActiveByDefault
import io.gitlab.arturbosch.detekt.api.internal.RequiresTypeResolution
import io.gitlab.arturbosch.detekt.rules.hasImplicitParameterReference
import io.gitlab.arturbosch.detekt.rules.implicitParameter
import org.jetbrains.kotlin.diagnostics.Errors
import org.jetbrains.kotlin.psi.KtDestructuringDeclarationEntry
import org.jetbrains.kotlin.psi.KtLambdaExpression
import org.jetbrains.kotlin.psi.KtNamedDeclaration
import org.jetbrains.kotlin.psi.KtParameter
import org.jetbrains.kotlin.psi.KtProperty
import org.jetbrains.kotlin.psi.psiUtil.getStrictParentOfType
import org.jetbrains.kotlin.resolve.BindingContext
/**
* Disallows shadowing variable declarations.
* Shadowing makes it impossible to access a variable with the same name in the scope.
*
* <noncompliant>
* fun test(i: Int, j: Int, k: Int) {
* val i = 1
* val (j, _) = 1 to 2
* listOf(1).map { k -> println(k) }
* listOf(1).forEach {
* listOf(2).forEach {
* }
* }
* }
* </noncompliant>
*
* <compliant>
* fun test(i: Int, j: Int, k: Int) {
* val x = 1
* val (y, _) = 1 to 2
* listOf(1).map { z -> println(z) }
* listOf(1).forEach {
* listOf(2).forEach { x ->
* }
* }
* }
* </compliant>
*
*/
@RequiresTypeResolution
@ActiveByDefault(since = "1.21.0")
class NoNameShadowing(config: Config = Config.empty) : Rule(config) {
override val issue = Issue(
javaClass.simpleName,
Severity.Defect,
"Disallow shadowing variable declarations.",
Debt.FIVE_MINS
)
override fun visitProperty(property: KtProperty) {
super.visitProperty(property)
checkNameShadowing(property)
}
override fun visitDestructuringDeclarationEntry(multiDeclarationEntry: KtDestructuringDeclarationEntry) {
super.visitDestructuringDeclarationEntry(multiDeclarationEntry)
checkNameShadowing(multiDeclarationEntry)
}
override fun visitParameter(parameter: KtParameter) {
super.visitParameter(parameter)
checkNameShadowing(parameter)
}
private fun checkNameShadowing(declaration: KtNamedDeclaration) {
val nameIdentifier = declaration.nameIdentifier ?: return
if (bindingContext.diagnostics.forElement(declaration).any { it.factory == Errors.NAME_SHADOWING }) {
report(CodeSmell(issue, Entity.from(nameIdentifier), "Name shadowed: ${nameIdentifier.text}"))
}
}
override fun visitLambdaExpression(lambdaExpression: KtLambdaExpression) {
super.visitLambdaExpression(lambdaExpression)
val implicitParameter = lambdaExpression.implicitParameter(bindingContext) ?: return
if (lambdaExpression.hasImplicitParameterReference(implicitParameter, bindingContext) &&
lambdaExpression.hasParentImplicitParameterLambda()
) {
report(
CodeSmell(
issue,
Entity.from(lambdaExpression),
"Name shadowed: implicit lambda parameter 'it'"
)
)
}
}
private fun KtLambdaExpression.hasParentImplicitParameterLambda(): Boolean =
getStrictParentOfType<KtLambdaExpression>()?.implicitParameter(bindingContext) != null
}