`duplicate-set-field` is reading from CoreLibs even though `diagnostics.libraryFiles` is set to 'Disable'

How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

Which OS are you using?

Windows

What is the issue affecting?

Formatting

Expected Behaviour

I do not see a warning for duplicate-set-field in my project.

Actual Behaviour

Hi

Thanks for this plugin. I am getting warning for duplicate-set-field on this line:

function playdate.update()

and the duplicate is in the CoreLibs folder here:

...\PlaydateSDK\CoreLibs\__stub.lua

I have set the CoreLibs folder to be ignored by the code checker:

"Lua.diagnostics.libraryFiles": "Disable",

Is this the expected behaviour?

Reproduction steps

1. Install Lua language server plugin
2. Set "Lua.diagnostics.libraryFiles": "Disable",
3. Create main.lua
4. Add the line function playdate.update() to main.lua
5. Observe warning:

	"resource": "/e:/dev/miner/Source/main.lua",
	"owner": "_generated_diagnostic_collection_name_#0",
	"code": "duplicate-set-field",
	"severity": 4,
	"message": "Duplicate field `update`.",
	"source": "Lua Diagnostics.",
	"startLineNumber": 72,
	"startColumn": 10,
	"endLineNumber": 72,
	"endColumn": 25,
	"relatedInformation": [
		{
			"startLineNumber": 5,
			"startColumn": 10,
			"endLineNumber": 5,
			"endColumn": 25,
			"message": ".twopolefilter.s",
			"resource": "/e:/devtools/PlaydateSDK/CoreLibs/__stub.lua"
		}
	]
}]

Additional Notes

No response

Log File

No response

Reproduce the warning using main.lua, the playdate.update() line, and the Lua.diagnostics.libraryFiles setting set to Disable; compare the diagnostic with CoreLibs/__stub.lua. Trace how duplicate-set-field diagnostics handle library files and verify the setting’s documented behavior. Done means the observed warning behavior is consistent with the intended configuration.