Logic to sort diagnostics by cost doesn't work because of async processing

まだ誰も着手していません。

I found some logic in diagnostics/init.lua that doesn't work as expected: https://github.com/LuaLS/lua-language-server/blob/87abc4245f2a24e1cc35851b6464af9588934286/script/core/diagnostics/init.lua#L158 tries to sort diagnostics by cost to run cheap diags first.

However, the code to measure to runtime at https://github.com/LuaLS/lua-language-server/blob/87abc4245f2a24e1cc35851b6464af9588934286/script/core/diagnostics/init.lua#L180 does to by calling os.clock() before and after invoking a given diagnostic.

This doesn't work if the diagnostic yields during execution, and most diagnostics do exactly that via `await.delay()`. The end result is that the order is pretty much random (which I confirmed by looking at the diagCost arrays with and without await.delay() enabled)

script/core/diagnostics/init.lua の 158 行付近にあるソートロジックと、180 行付近にある実行時間の測定から始めます。問題を再現するために、await.delay() を有効にした場合と無効にした場合の診断コスト配列を比較します。診断の実行が yield する場合でも、意味のある測定コストに基づいて診断が順序付けられれば完了です。

索引モデルが issue の本文から書いたものです。