Benchling jscodeshift script to convert code to use React.createElement

rd-to-create-element.js

/**
 * jscodeshift script to convert our way of creating React elements in CoffeeScript to
 * React.createElement. The create-element-to-jsx script then converts the result to JSX.
 *
 * For example, this code:
 * rd.div(myProps, child1, child2)
 *
 * becomes:
 * React.createElement('div', myProps, child1, child2)
 *
 * and this code:
 * const Glyphicon = React.createFactory(require('react-components/glyphicon'));
 * ...
 * Glyphicon(myProps, child1, child2)
 *
 * becomes
 * import Glyphicon from 'react-components/glyphicon'
 * ...
 * React.createElement(Glyphicon, myProps, child1, child2)
 *
 * Test case:
 * http://astexplorer.net/#/Pq226Pd7fS/1
 */


export default (fileInfo, api) => {
  const j = api.jscodeshift;
  const root = j(fileInfo.source);
  const customComponents = transformComponentImports(j, root);
  transformComponentUsages(j, root, customComponents);
  return root.toSource();
};

// The result of this command from the coffee directory:
// grep -oh -R '\srd\.[^ ()]*\s' * | sort -u | sed 's/ rd\.\(.*\) /\1/'
const HTML_TAGS = [
  'a', 'address', 'audio', 'b', 'br', 'button', 'col', 'colgroup', 'dd', 'div', 'dl', 'dt', 'em',
  'fieldset', 'form', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'hr', 'i', 'iframe', 'img', 'input',
  'kbd', 'label', 'legend', 'li', 'ol', 'option', 'p', 'polygon', 'select', 'small', 'source',
  'span', 'strong', 'sub', 'svg', 'table', 'tbody', 'td', 'textarea', 'tfoot', 'th', 'thead', 'tr',
  'u', 'ul',
];

// Matchers to make jscodeshift matching a little more concise.
const call = (callee, args) => ({type: 'CallExpression', callee, arguments: args});
const access = (object, property) => ({type: 'MemberExpression', object, property});
const id = (name) => ({type: 'Identifier', name});

/**
 * This function finds all usages of createFactory in imports, rewrites them to
 * just import the component directly, and returns an array of the names of these
 * components. That way, our later rewriting code can know to include these in the
 * names of all valid tags.
 */
const transformComponentImports = (j, root) => {
  const extractValues = (path) => ({
    // The name of the import, e.g. "Glyphicon".
    importId: path.node.declarations[0].id.name,
    // The file path of the import, e.g. "react-components/glyphicon".
    importPath: path.node.declarations[0].init.arguments[0].arguments[0].value,
  });
  const resultImportIds = [];
  root.find(j.VariableDeclaration, {
    declarations: [{
      id: {type: 'Identifier'},
      init: call(
        access(id('React'), id('createFactory')),
        [call(id('require'), [{type: 'Literal'}])]),
    }],
  }).filter((path) => {
    // Make sure that the identifier being imported isn't used in some unexpected way. It should be
    // used once for the import itself and aside from that, only in call expressions.
    const {importId} = extractValues(path);
    const numUsages = root.find(j.Identifier, id(importId)).size();
    const numCalls = root.find(j.CallExpression, call(id(importId), {})).size();
    return numCalls === numUsages - 1;
  }).forEach((path) => {
    const {importId} = extractValues(path);
    resultImportIds.push(importId);
  }).replaceWith((path) => {
    const {importId, importPath} = extractValues(path);
    const result = j.importDeclaration(
      [j.importDefaultSpecifier(j.identifier(importId))],
      j.literal(importPath)
    );
    result.comments = getAllCommentsUnderNode(path.node, j);
    return result;
  });
  return resultImportIds;
};

const transformComponentUsages = (j, root, customComponents) => {
  // Turn appropriate function calls into React.createElement.
  root.find(
    j.CallExpression
  ).forEach((path) => {
    const replaceTag = getReplaceTag(j, path.node, customComponents);
    if (replaceTag == null) {
      return;
    }
    const {node} = path;
    const calleeComments = getAllCommentsUnderNode(node.callee, j);
    node.callee = j.memberExpression(j.identifier('React'), j.identifier('createElement'));
    node.callee.comments = calleeComments;
    node.arguments.unshift(replaceTag);
    path.replace(node);
  });
};

const getReplaceTag = (j, callNode, customComponents) => {
  const {callee} = callNode;
  if (callee.type === 'MemberExpression'
      && callee.object.type === 'Identifier'
      && callee.object.name === 'rd'
      && callee.property.type === 'Identifier'
      && includes(HTML_TAGS, callee.property.name)) {
    return j.literal(callee.property.name);
  } else if (callee.type === 'Identifier'
      && includes(customComponents, callee.name)) {
    return callee.name;
  }
  return null;
};

// Little helper since we don't have Array.prototype.includes.
const includes = (arr, elem) => {
  return arr.indexOf(elem) > -1;
};

const getAllCommentsUnderNode = (node, j) => {
  const comments = [];
  j.types.visit(node, {
    visitNode(path) {
      if (path.node.comments) {
        for (const comment of path.node.comments) {
          comment.leading = false;
          comment.trailing = true;
          comments.push(comment);
        }
      }
      this.traverse(path);
    },
  });
  return comments;
};

z_LICENSE

The MIT License (MIT)

Copyright (c) 2016 Benchling, Inc.

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the Software, and to permit persons to whom the Software is furnished to do so,
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The above copyright notice and this permission notice shall be included in all
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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