gatsby-transformer-remote-filesystem/extend-file-node.js

Adds a localURL field to any File node created with gatsby-source-filesystem's createRemoteFileNode

"use strict";

const {
  GraphQLString
} = require('gatsby/graphql');

const fs = require('fs-extra');

const path = require('path');

module.exports = ({
  type,
  getNodeAndSavePathDependency,
  pathPrefix = ''
}, pluginOptions) => {
  if (type.name !== 'File') {
    return {};
  }

  return {
    localURL: {
      type: GraphQLString,
      args: {},
      description: 'Copy file to static directory and return public url to it',
      resolve: (file, fieldArgs, context) => {
        const details = getNodeAndSavePathDependency(file.id, context.path);
        const parentDir = pluginOptions.fingerprintDirectory ? file.internal.contentDigest : '';
        const fileName = pluginOptions.fingerprintDirectory ? `${file.name}${details.ext}` : `${file.name}-${file.internal.contentDigest}${details.ext}`;
        const dirPath = path.join(process.cwd(), 'public', 'static', parentDir);
        const publicPath = path.join(dirPath, fileName);
        const shouldProcess = pluginOptions.mediaTypes ? pluginOptions.mediaTypes.includes(file.internal.mediaType) : true;

        if (shouldProcess && !fs.existsSync(publicPath)) {
          fs.ensureDirSync(dirPath);
          fs.copy(details.absolutePath, publicPath, err => {
            if (err) {
              console.error(`error copying file from ${details.absolutePath} to ${publicPath}`, err);
            }
          });
        } else if (!shouldProcess) {
          return null;
        }

        return pluginOptions.fingerprintDirectory ? `${pathPrefix}/static/${parentDir}/${fileName}` : `${pathPrefix}/static/${fileName}`;
      }
    }
  };
};