@memoized-dom/language-service

TypeScript editor diagnostics and code fixes for memoized-dom. Compiler errors come from @memoized-dom/compiler's structured graph diagnostic API, so the editor, Vite overlay, and direct compiler report the same restrictions. Compiler diagnostics preserve the authored ESTree start/end range, so route attributes, invalid writes, and other failures are underlined at their actual source node instead of a generic one-character position.

Add the plugin to the application tsconfig.json:

{
  "compilerOptions": {
    "plugins": [
      {
        "name": "@memoized-dom/language-service"
      }
    ]
  }
}

TypeScript language-service plugins run in editors powered by tsserver. They do not add diagnostics to standalone tsc; the analysis core is kept separate so a future CLI can report the same diagnostics in CI.

The first diagnostic suggests const for initialized let bindings that are never reassigned. Its message explains that memoized-dom reactivity follows reads and writes rather than declaration keywords; const arrays and objects can still mutate their contents. The editor fix changes only the declaration keyword.

Set "preferConst": false on the plugin entry to disable this diagnostic. Set "compilerDiagnostics": false only when compiler errors should be hidden from tsserver.