@joblift/babel-plugin-transform-postcss/dist/plugin.js

PostCSS Babel Transform

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.stopServer = exports.startServer = undefined;
exports.default = transformPostCSS;

var _path = require('path');

var _child_process = require('child_process');

// note: socket path is important to keep short as it will be truncated if it
// exceeds certain platform limits. for this reason, we're writing to /tmp
// instead of using os.tmpdir (which can, on platforms like darwin, be quite
// long & per-process).
const projectId = process.cwd().toLowerCase().replace(/[^a-z]/ig, '');
const socketName = `bptp-${projectId}.sock`;
const socketPath = (0, _path.join)('/tmp', socketName);
const tmpPath = (0, _path.join)('/tmp', `bptp-${projectId}`);

const nodeExecutable = process.argv[0];
const clientExcutable = (0, _path.join)(__dirname, 'postcss-client.js');
const serverExcutable = (0, _path.join)(__dirname, 'postcss-server.js');

let server;

const startServer = () => {
  server = (0, _child_process.spawn)(nodeExecutable, [serverExcutable, socketPath, tmpPath], {
    env: process.env, // eslint-disable-line no-process-env
    stdio: 'inherit'
  });

  server.unref();
};

const stopServer = () => {
  if (!server) {
    return;
  }

  server.kill();
  server = null;
  process.removeListener('exit', stopServer);
};

const launchServer = () => {
  if (server) {
    return;
  }

  startServer();

  process.on('exit', stopServer);
};

const defaultExtensions = ['.css'];

const getStylesFromStylesheet = (stylesheetPath, file, config, configExtensions) => {
  const stylesheetExtension = (0, _path.extname)(stylesheetPath);

  const extensions = Array.isArray(configExtensions) ? configExtensions : defaultExtensions;

  if (extensions.indexOf(stylesheetExtension) !== -1) {
    launchServer();
    const requiringFile = file.opts.filename;
    const cssFile = (0, _path.resolve)((0, _path.dirname)(requiringFile), stylesheetPath);
    const data = JSON.stringify({ cssFile, config });
    const execArgs = [clientExcutable, socketPath, data];
    const result = (0, _child_process.execFileSync)(nodeExecutable, execArgs, {
      env: process.env // eslint-disable-line no-process-env
    }).toString();

    return JSON.parse(result || '{}');
  }

  return undefined;
};

function transformPostCSS({ types: t }) {

  return {
    visitor: {
      CallExpression(path, { file }) {
        const { callee: { name: calleeName }, arguments: args } = path.node;

        if (calleeName !== 'require' || !args.length || !t.isStringLiteral(args[0])) {
          return;
        }

        const [{ value: stylesheetPath }] = args;
        const { config, extensions } = this.opts;
        const tokens = getStylesFromStylesheet(stylesheetPath, file, config, extensions);

        if (tokens !== undefined) {
          const expression = path.findParent(test => test.isVariableDeclaration() || test.isExpressionStatement());

          expression.addComment('trailing', ` @related-file ${stylesheetPath}`, true);

          path.replaceWith(t.objectExpression(Object.keys(tokens).map(token => t.objectProperty(t.stringLiteral(token), t.stringLiteral(tokens[token])))));
        }
      },
      ImportDeclaration(path, { file }) {
        const stylesheetPath = path.node.source.value;

        if (path.node.specifiers.length !== 1) {
          return;
        }

        const { config, extensions } = this.opts;
        const tokens = getStylesFromStylesheet(stylesheetPath, file, config, extensions);

        if (tokens) {
          const styles = t.objectExpression(Object.keys(tokens).map(token => t.objectProperty(t.stringLiteral(token), t.stringLiteral(tokens[token]))));
          /* eslint-disable new-cap */

          const variableDeclaration = t.VariableDeclaration('var', [t.VariableDeclarator(path.node.specifiers[0].local, styles)]);

          /* eslint-enable new-cap */
          path.addComment('trailing', ` @related-file ${stylesheetPath}`, true);
          path.replaceWith(variableDeclaration);
        }
      }
    }
  };
}

exports.startServer = startServer;
exports.stopServer = stopServer;