.mts / .mjs files are not indexed (ESM TypeScript/JS module extensions skipped by file discovery)

[Romainnoo145]

Summary

.mts and .mjs files are not indexed at all. These are the standard TypeScript / JavaScript ES module file extensions (.mts = TS ESM, .mjs = JS ESM, TS handbook). tree-sitter-typescript/javascript parse them identically to .ts/.js, so this looks like a file-discovery glob omission rather than a parser limitation.

For Node.js codebases that use the explicit ESM extensions (very common in modern Node 20/22 backends, CLIs, and tooling), this means the entire backend is invisible to the graph while the .ts/.tsx frontend indexes perfectly.

Reproduction

On a monorepo whose backend/CLI/packages are authored in .mts:

codegraph init -i .
codegraph status        # languages show only tsx / typescript — no .mts
codegraph files | grep -c '\.mts'   # -> 0
codegraph query "<a symbol that lives in a .mts file>"   # -> No results found

Evidence (real repo)

A repo with 133 git-tracked .mts files:

• codegraph status → Files: 196, languages: tsx 103, typescript 64 — zero .mts
• codegraph files | grep -c '\.mts' → 0
• codegraph query for symbols known to live in .mts files → No results found
• codegraph query "Client" (a .tsx symbol) → works perfectly, returns Clients.tsx:26, ClientDTO, ClientCard with file:line

So discovery + parsing + search all work for .ts/.tsx; .mts/.mjs are simply never picked up.

Expected

.mts and .mjs are discovered and parsed the same as .ts / .js (and .cts/.cjs for completeness — the CommonJS explicit extensions).

Notes

• There is no index flag (--include / extension list) and no documented config (see Document config or create a json schema for it #283) to add extensions as a workaround, so end users can't opt in manually.
• Likely a one-line addition to the file-discovery extension set + language mapping.

Environment

• CodeGraph v0.9.3 (standalone installer, bundled runtime)
• Linux x64, Node 22