Closes#7844
This change uses tree-sitter highlights as a method of showing
typescript errors prettily, keeping regex as simple as possible:
<img width="832" height="446" alt="Screenshot 2025-11-11 at 3 40 24 PM"
src="https://github.com/user-attachments/assets/0b3b6cf1-4d4d-4398-b89b-ef5ec0df87ec"
/>
It covers three main areas:
1. Diagnostics
Diagnostics are now rendered with language-aware typescript, by
providing the project's language registry.
2. Vtsls
The LSP provider for typescript now implements the
`diagnostic_message_to_markdown` function in the `LspAdapter` trait, so
as to provide Diagnostics with \`\`\`typescript...\`\`\`-style code
blocks for any selection of typescript longer than one word. In the
single-word case, it simply wraps with \`\`
3. Typescript's `highlights.scm`
`vtsls` doesn't provide strictly valid typescript in much of its
messaging. Rather, it returns a message with snippets of typescript
values which are invalid. Tree-sitter was not properly highlighting
these snippets because it was expecting key-value formats. For instance:
```
type foo = { foo: string; bar: string; baz: number[] }
```
is valid, whereas simply
```
{ foo: string; bar: string; baz: number[] }
```
is not.
Therefore, highlights.scm needed to be adjusted in order to
pattern-match on literal values that might be returned from the vtsls
diagnostics messages. This was done by a) identifying arrow functions on
their own, and b) augmenting the `statment_block` pattern matching in
order to match on values which were clearly object literals.
This approach may not be exhaustive - I'm happy to work on any
additional cases we might identify from `vtsls` here - but hopefully
demonstrates an extensible approach to making these messages look nice,
without taking on the technical burden of extensive regex.
Release Notes:
- Show pretty TypeScript errors with language-aware Markdown.
4adec27a3d