@nestjs/cli/lib/compiler/defaults/swc-defaults.js

Nest - modern, fast, powerful node.js web framework (@cli)

export const swcDefaultsFactory = (tsOptions, configuration, tsConfigExclude = []) => {
    const builderOptions = typeof configuration?.compilerOptions?.builder !== 'string'
        ? configuration?.compilerOptions?.builder?.options
        : {};
    return {
        swcOptions: {
            sourceMaps: tsOptions?.sourceMap || (tsOptions?.inlineSourceMap && 'inline'),
            module: {
                type: 'commonjs',
            },
            jsc: {
                target: 'es2021',
                parser: {
                    syntax: 'typescript',
                    decorators: true,
                    dynamicImport: true,
                },
                transform: {
                    legacyDecorator: true,
                    decoratorMetadata: true,
                    useDefineForClassFields: false,
                },
                keepClassNames: true,
                baseUrl: tsOptions?.baseUrl,
                paths: tsOptions?.paths,
            },
            minify: false,
            swcrc: true,
        },
        cliOptions: {
            outDir: tsOptions?.outDir ? convertPath(tsOptions.outDir) : 'dist',
            filenames: [configuration?.sourceRoot ?? 'src'],
            sync: false,
            extensions: ['.js', '.ts'],
            copyFiles: false,
            includeDotfiles: false,
            ignore: tsConfigExclude.length ? tsConfigExclude : undefined,
            quiet: false,
            watch: false,
            stripLeadingPaths: shouldStripLeadingPaths(tsOptions?.rootDir, configuration?.sourceRoot ?? 'src'),
            ...builderOptions,
        },
    };
};
/**
 * Mirrors tsc's output layout: tsc flattens the source directory out of the
 * output when its (effective) rootDir is the source root, so swc must strip
 * leading paths in the same cases — no rootDir configured (tsc infers the
 * common source directory), or a rootDir that points at the source root
 * (relative or resolved absolute). A rootDir above the source root (e.g. '.')
 * keeps the source directory in the output, so nothing is stripped.
 */
function shouldStripLeadingPaths(rootDir, sourceRoot) {
    if (!rootDir) {
        return true;
    }
    const normalizedRootDir = convertPath(rootDir).replace(/\/+$/, '');
    const normalizedSourceRoot = convertPath(sourceRoot)
        .replace(/^\.\//, '')
        .replace(/\/+$/, '');
    return (normalizedRootDir === normalizedSourceRoot ||
        normalizedRootDir.endsWith(`/${normalizedSourceRoot}`));
}
/**
 * Converts Windows specific file paths to posix
 * @param windowsPath
 */
function convertPath(windowsPath) {
    return windowsPath
        .replace(/^\\\\\?\\/, '')
        .replace(/\\/g, '/')
        .replace(/\/\/+/g, '/');
}