Language-tag checking

How Kiira detects when a ts fence contains JSX, warns that it should be tsx, checks it as tsx anyway to surface real type errors, and rewrites the tag with kiira check --fix.

The problem

A code fence tagged ts that actually contains JSX is mislabeled — JSX belongs in a tsx fence. Beyond being wrong for syntax highlighting, it changes how the snippet should be compiled, and a naive checker would either crash on the JSX or report misleading errors.

What Kiira does

When Kiira sees a ts (or typescript) fence whose contents include JSX, it:

Warns that the fence should be tagged tsx.
Checks it as tsx anyway, so you still get real, accurate type errors for the snippet instead of a parse failure or noise.

``ts
// Kiira warns: this looks like JSX — tag it `tsx`.
// It still type-checks the snippet as tsx so you get real errors.
const el = <Button onClick={handleClick}>Save</Button>
``

Fixing the tag

Run kiira check --fix to rewrite the language tag from ts/typescript to tsx:

<!-- after `kiira check --fix` -->
``tsx
const el = <Button onClick={handleClick}>Save</Button>
``

Because Kiira already checks mislabeled fences as tsx, fixing the tag doesn't change the validation result — it just makes the Markdown accurate and improves highlighting.

Non-React JSX?

If the JSX targets a framework other than the default React runtime (Solid, Preact, …), you may also need a jsxImportSource override. See Per-glob overrides.