# `mix mf2_wasm_editor.sync`
[🔗](https://github.com/elixir-localize/mf2_wasm_editor/blob/v0.2.0/lib/mix/tasks/mf2_wasm_editor.sync.ex#L1)

Sync the vendored grammar + WASM + queries from the published
[`tree-sitter-mf2`](https://www.npmjs.com/package/tree-sitter-mf2)
npm package.

This package embeds the MF2 grammar as browser-facing artefacts:

  * **WASM** (`priv/static/tree-sitter-mf2.wasm`) — what the
    `web-tree-sitter` runtime actually loads.

  * **Queries** (`priv/static/highlights.scm`) — fetched at
    runtime by the JS hook.

  * **Grammar source** (`priv/grammar/`) — parser.c, parser.h,
    grammar.json, node-types.json, grammar.js. Kept alongside so
    the WASM can be regenerated locally with `--build-wasm`.

The canonical source is the npm package, pinned to an exact
version at the top of this module (`@tree_sitter_mf2_version`).
Bump that string and re-run the task to move to a new grammar
release. Keep the pin in step with `localize_mf2_treesitter`'s
own sync task — tree shape is the API boundary between
server-side parse (NIF) and browser-side parse (WASM editor); a
version skew can produce different trees for the same input.

## Usage

    # Fetch from npm at the pinned version and update local files.
    mix mf2_wasm_editor.sync

    # Fail (exit 1) if anything has drifted from the pinned
    # version; do not modify files. Intended for CI.
    mix mf2_wasm_editor.sync --check

    # Additionally rebuild priv/static/tree-sitter-mf2.wasm from
    # the vendored grammar instead of using the prebuilt .wasm
    # shipped in the npm tarball. Requires a local `mf2_treesitter`
    # checkout (via MF2_TREESITTER_DIR) with `npm install` already
    # run, plus emcc / docker / podman on PATH.
    mix mf2_wasm_editor.sync --build-wasm

## Offline / local-iteration override

If you're iterating on the grammar locally and want this task to
read from a sibling checkout rather than hit the network, set
`MF2_TREESITTER_DIR`:

    MF2_TREESITTER_DIR=/path/to/mf2_treesitter mix mf2_wasm_editor.sync

With that set, file layouts must match the npm package layout
(which also matches the repo layout): `grammar.js` at the root,
`src/parser.c`, `queries/highlights.scm`, `wasm/tree-sitter-mf2.wasm`.

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*Consult [api-reference.md](api-reference.md) for complete listing*