WASM API

The cmakefmt WASM build powers the browser playground and can be used in any JavaScript or TypeScript project.

Building

# Install wasm-pack
cargo install wasm-pack

# Build the WASM package
wasm-pack build --target web

This produces a pkg/ directory with the WASM module and TypeScript bindings.

API

The WASM module exports a single function:

format(source: string, config_yaml: string): string

Formats a CMake source string using the given YAML config.

Parameters:

• source — the CMake source code to format
• config_yaml — a YAML string with config options (same format as .cmakefmt.yaml); pass "" for defaults

Returns: the formatted source code as a string.

Throws: if parsing fails or the config is invalid.

Usage in the browser

<script type="module">
  import init, { format } from './pkg/cmakefmt.js';

  await init();

  const source = 'CMAKE_MINIMUM_REQUIRED(VERSION 3.20)';
  const config = 'format:\n  line_width: 100';
  const formatted = format(source, config);
  console.log(formatted);
  // → cmake_minimum_required(VERSION 3.20)
</script>

Usage in Node.js

const { format } = require('./pkg/cmakefmt.js');

const formatted = format(
  'SET(FOO bar baz)',
  ''  // use defaults
);
console.log(formatted);
// → set(FOO bar baz)

Limitations

• The WASM build does not include the CLI, LSP server, or file discovery
• Custom command specs must be passed as part of the config YAML
• Performance is comparable to native for small files; large files may be slower due to WASM overhead