#@swc/cli

#Usage

Run the following to download pre-built binaries:

pnpm i -D @swc/cli @swc/core

npm i -D @swc/cli @swc/core

yarn add -D @swc/cli @swc/core

Then, you can transpile your files:

# Transpile one file and emit to stdout
npx swc ./file.js

# Transpile one file and emit to `output.js`
npx swc ./file.js -o output.js

# Transpile and write to /output dir
npx swc ./my-dir -d output

#Flow input

To compile Flow code with the CLI, point swc at a .swcrc file that sets jsc.parser.syntax to "flow":

{
  "jsc": {
    "parser": {
      "syntax": "flow"
    }
  }
}

npx swc input.js --config-file .swcrc -o output.js

For JSX-flavored Flow files, set jsx: true and compile .jsx inputs with the same config. See the Flow guide for the full list of parser options.

#Options

#--filename (-f)

Filename to use when reading from stdin. This will be used in source maps and errors.

npx swc -f input.js

#--config-file

Path to a .swcrc file to use.

npx swc input.js --config-file .swcrc

#--env-name

The name of the 'env' to use when loading configs and plugins. Defaults to the value of SWC_ENV, or else NODE_ENV, or else development.

npx swc input.js --env-name='test'

#--no-swcrc

Whether or not to look up .swcrc files.

npx swc input.js --no-swcrc

#--ignore

List of glob paths to not compile.

npx swc src --ignore **/*.test.js

#--only

List of glob paths to only compile

Example:

npx swc src --only **/*.js

#--watch (-w)

To automatically recompile files on changes, install chokidar:

npm i -D chokidar

Then, add the -w flag:

npx swc input.js -w

#--quiet (-q)

Suppress compilation output.

npx swc input.js -q

#--source-maps (-s)

Values: true|false|inline|both

npx swc input.js -s

#--source-map-target

Define the file for the source map.

npx swc input.js -s --source-map-target input.map.js

#--source-file-name

Set sources[0] on returned source map

#--source-root

The root from which all sources are relative.

#--out-file (-o)

Compile all input files into a single file.

npx swc input.js -o output.js

#--out-dir (-d)

Compile an input directory of modules into an output directory.

npx swc src -d dist

#--copy-files (-D)

When compiling a directory, copy over non-compilable files.

npx swc src --copy-files

#--include-dotfiles

Include dotfiles when compiling and copying non-compilable files.

npx swc src --include-dotfiles

#--config (-C)

Override a config from .swcrc file.

npx swc src -C module.type=amd -C module.moduleId=hello

#--sync

Invoke swc synchronously. Useful for debugging.

npx swc src --sync

#--log-watch-compilation

Log a message when a watched file is successfully compiled.

npx swc input.js --log-watch-compilation

#--extensions

Use specific extensions.

#--strip-leading-paths

Remove the leading directory (including all parent relative paths) when building the final output path. As an example it compiles all modules under src folder to dist folder, without create the src folder inside of dist.

npx swc src -d dist --strip-leading-paths

#use in nodejs script

const { swcDir } = require('@swc/cli');

const swcOptions = {
    jsc: {
        target: 'esnext',
        externalHelpers: true,
    },
    module: {
        type: 'commonjs',
    },
    sourceMaps: true,
};

swcDir({
    cliOptions: {
        outDir: './dist',
        watch: true,
        filenames: ['./src'],
        extensions: ['.ts'],
        stripLeadingPaths: true,
    },
    swcOptions,
    callbacks: {
        onSuccess: e => {
            console.log(e);
        },
        onFail: e => {
            console.log(e);
        },
        onWatchReady: () => {},
    },
});

Please note that when using callbacks, the --quiet (-q) will always be true.

#--out-file-extension

Use a specific extension for the output files.

As an example, if you want to render your es6 output to .mjs file extensions, you could call:

npx swc input.js --out-file-extension mjs

Please note that if you are compiling multiple files, you will also need to make sure that your imports are resolved with the appropriate extension. You can do so by making use of the resolveFully and outFileExtension module options:

{
  "module": {
    "resolveFully": true,
    "outFileExtension": "mjs"
  }
}