permissions-dispatcher/PermissionsDispatcher · error · DuplicatedMethodNameException

'${e.simpleString()}()' has duplicated '@NeedsPermission' me

Error message

'${e.simpleString()}()' has duplicated '@NeedsPermission' method. The method annotated with '@NeedsPermission' must has the unique name.

What it means

The PermissionsDispatcher processor requires every @NeedsPermission-annotated method in a class to have a unique simple name, because generated dispatcher code references these methods by name. Two annotated methods with the same name (e.g. Java overloads, or same-named methods in a class hierarchy) make the generated binding ambiguous, so compilation fails.

Source

Thrown at processor/src/main/kotlin/permissions/dispatcher/processor/util/Validators.kt:137

                throw MixPermissionTypeException(it, SYSTEM_ALERT_WINDOW)
            }
        }
    }
}

fun checkSpecialPermissionsWithNeverAskAgain(items: List<ExecutableElement>, annotationClass: Class<OnNeverAskAgain> = OnNeverAskAgain::class.java) {
    items.forEach {
        val permissionValue = it.getAnnotation(annotationClass).permissionValue()
        if (permissionValue.contains(WRITE_SETTINGS) || permissionValue.contains(SYSTEM_ALERT_WINDOW)) {
            throw SpecialPermissionsWithNeverAskAgainException()
        }
    }
}

fun checkDuplicatedMethodName(items: List<ExecutableElement>) {
    items.forEach { item ->
        items.firstOrNull { it != item && it.simpleName == item.simpleName }?.let {
            throw DuplicatedMethodNameException(item)
        }
    }
}

View on GitHub (pinned to 74b532bf1f)

Solutions

Rename one of the duplicated @NeedsPermission methods to a unique, descriptive name
Merge overloads into a single annotated method with default parameters instead of multiple same-named overloads
If the clash comes from inheritance, rename the subclass method or remove the annotation from one level

Example fix

// before
@NeedsPermission(Manifest.permission.CAMERA)
fun request() { }

@NeedsPermission(Manifest.permission.ACCESS_FINE_LOCATION)
fun request() { }

// after
@NeedsPermission(Manifest.permission.CAMERA)
fun requestCamera() { }

@NeedsPermission(Manifest.permission.ACCESS_FINE_LOCATION)
fun requestLocation() { }

Defensive patterns

Strategy: validation

Validate before calling

// scan for duplicate simple names among @NeedsPermission methods before building
val annotated = listOf("requestCamera", "requestLocation") // names of @NeedsPermission methods
val duplicates = annotated.groupingBy { it }.eachCount().filterValues { it > 1 }
require(duplicates.isEmpty()) { "Duplicate @NeedsPermission method names: $duplicates" }

Type guard

fun List<String>.hasUniqueNames(): Boolean = size == distinct().size

require(annotatedMethodNames.hasUniqueNames()) { "@NeedsPermission methods must have unique names" }

Prevention

Never overload @NeedsPermission-annotated methods; use unique descriptive names per permission set
Prefer Kotlin default parameters over overloads for optional arguments on annotated methods
When using inheritance, ensure subclass annotated methods do not reuse base-class annotated method names

When it happens

Trigger: Declaring two @NeedsPermission methods with identical simpleName in the same class (e.g. overloads fun request() and fun request(s: String)), or having a subclass and superclass both declare @NeedsPermission methods with the same simple name that the processor sees together.

Common situations: Java-style method overloading carried into Kotlin annotated methods; refactoring two features to reuse a generic name like 'request' or 'onPermission'; inheritance hierarchies where a base class's annotated method name is reused in a subclass.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

AI-assisted analysis of permissions-dispatcher/PermissionsDispatcher@74b532bf1f (2026-09-08). Data as JSON: /api/errors/26933e7791b8ed08. Report an issue: GitHub.