I'm running Android Studio Preview versions (currently Android Studio Narwhal | 2025.1.1 Canary 3) & noticed that I'm getting a lot of warnings about conflicts between member functions & extensions with various calls including toString() & indexOf().

I recall AS prompting me a few versions back to replace certain function calls with extensions & I haven't noticed these warnings until I installed the current AS preview version - & I'm not sure what to do about them. It appears that the issue is (at least in some cases) due to nullable vs non nullable parameters & how they're dealt with by the function vs the extension.

I know I can differentiate between the member function & extension at a module level by importing the extension & aliasing it - eg:

import kotlin.toString as toStringExtension

& then calling it using .toStringExtension() - but this seems like a clunky way to deal with it.

Is the warning just a bug in the preview version of AS (or lint) or are we going to have to deal with this whenever there's a conflict between a member function & an extension going forward? I can understand receiving the warning if there's a conflict between a built in Kotlin function & an extension I've created, but the warnings I'm seeing are in cases where they are both built into Kotlin.

I'm running Android Studio Preview versions (currently Android Studio Narwhal | 2025.1.1 Canary 3) & noticed that I'm getting a lot of warnings about conflicts between member functions & extensions with various calls including toString() & indexOf().

I recall AS prompting me a few versions back to replace certain function calls with extensions & I haven't noticed these warnings until I installed the current AS preview version - & I'm not sure what to do about them. It appears that the issue is (at least in some cases) due to nullable vs non nullable parameters & how they're dealt with by the function vs the extension.

I know I can differentiate between the member function & extension at a module level by importing the extension & aliasing it - eg:

import kotlin.toString as toStringExtension

& then calling it using .toStringExtension() - but this seems like a clunky way to deal with it.

Is the warning just a bug in the preview version of AS (or lint) or are we going to have to deal with this whenever there's a conflict between a member function & an extension going forward? I can understand receiving the warning if there's a conflict between a built in Kotlin function & an extension I've created, but the warnings I'm seeing are in cases where they are both built into Kotlin.

• kotlin
• android-studio
• extension-methods
• lint

1 Answer 1

So it seems this was a bug in AS which has been resolved in the Narwhal Canary 4 release.

False positive for lint issue `MemberExtensionConflict` if extension function receiver is nullable