index.js

'use strict';

module.exports = {
  name: require('./package').name,
  included() {
    // Defaults that can be overriden by options
    this.components = [];
    this.plugins = [];
    this.theme = 'themes/prism.css';

    let app = findHost(this);

    if (app.options && app.options['ember-prism']) {
      const options = app.options['ember-prism'];
      const components = options.components;
      const plugins = options.plugins || [];
      const theme = options.theme;

      if (!plugins.includes('normalize-whitespace')) {
        plugins.push('normalize-whitespace');
      }

      if (theme && theme !== 'none') {
        this.theme = `themes/prism-${theme}.css`;
      }

      if (components) {
        components.forEach((component) => {
          this.components.push(`components/prism-${component}.js`);
        });
      }

      if (plugins) {
        plugins.forEach((plugin) => {
          /**
           * Most Prism plugins contains both a js file and a css file, but there
           * are exception. `highlight-keywords` for instance, does not have a
           * css file.
           *
           * When the plugin is imported, the app should check for file existence
           * before calling `app.import()`.
           */

          // file extensions to be tested for existence.
          const fileExtensions = ['js', 'css'];

          fileExtensions.forEach((fileExtension) => {
            const nodeAssetsPath = `plugins/${plugin}/prism-${plugin}.${fileExtension}`;

            if (maybeResolve(`prismjs/${nodeAssetsPath}`)) {
              this.plugins.push(nodeAssetsPath);
            }
          });
        });
      }
    }

    app.import('vendor/ember-prism.js');

    this._super.included.apply(this, arguments);
  },
  options: {
    'ember-cli-babel': { enableTypeScriptTransform: true },
    nodeAssets: {
      prismjs() {
        return {
          import: ['prism.js', this.theme].concat(
            this.components,
            this.plugins,
          ),
        };
      },
    },
  },
};

function maybeResolve(path) {
  try {
    return require.resolve(path);
  } catch (error) {
    if (error.code === 'MODULE_NOT_FOUND') {
      return null;
    } else {
      throw error;
    }
  }
}

// Polyfill [Addon._findHost](https://ember-cli.com/api/classes/Addon.html#method__findHost) for older versions of ember-cli
function findHost(addon) {
  var current = addon;
  var app;

  do {
    app = current.app || app;
  } while (current.parent.parent && (current = current.parent));

  return app;
}