Hot Reload: Clear resource cache on metadata update

[tmat]

Description

ResourceManager maintains cache of loaded resource strings. In order to support Hot Reload of resource strings the cache needs to be cleared when Hot Reload change is applied.

Reproduction Steps

Resx file is updated during Hot Reload.

Expected behavior

New and updated resources are available without restarting.

Actual behavior

New resources/updated values are not available to the app until it restarts.

Regression?

No

Known Workarounds

No response

Configuration

No response

Other information

No response

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[ericstj]

@tmat did you already have a fix in mind for this or were you looking for help? What's the priority of this scenario?

[tmat]

Help would be appreciated.

The fix is to hook up MetadataUpdateHandler and call ResourceManager.ReleaseAllResources on each existing ResourceManager. When a ResourceManager is created and Hot Reload is enabled in the process it could weakly subscribe to a cleanup event that is then invoked from the update handler.

Priority depends on #115910. Need to be prioritized together since both need to be implemented in order for Hot Reload to work. Once these are done more work needs to be done in Roslyn/dotnet-watch/IDE for end to end: see dotnet/roslyn#75133

In general, we are trying to make significant progress on removing numerous limitations of EnC/Hot Reload. Updating resources is one of the changes that requires restarting app and therefore degrades Hot Reload experience. I'd say it's P2 when compared to other issues we are currently looking into.