Babel compile html-entities@1.2.1 code generate invalid JavaScript code

[copyrighthero]

Bug Report

• I would like to work on a fix!

Current Behavior

When using babel to compile html-entities from node_modules, specifically when using the the following environment and configuration file, using the command babel --config-file ./babel.config.js node_modules/html-entities/lib/html5-entities.js > ~/Desktop/html5-entities.js, the generated code is invalid.

Original source code:

Html5Entities.prototype.encode = function(str) {
    if (!str || !str.length) {
        return '';
    }
    var strLength = str.length;
    var result = '';
    var i = 0;
    while (i < strLength) {
        var charInfo = charIndex[str.charCodeAt(i)];
        if (charInfo) {
            var alpha = charInfo[str.charCodeAt(i + 1)];
            if (alpha) {
                i++;
            } else {
                alpha = charInfo[''];
            }
            if (alpha) {
                result += "&" + alpha + ";";
                i++;
                continue;
            }
        }
        result += str.charAt(i);
        i++;
    }
    return result;
};

Generated source code

31}, Html5Entities.prototype.encode = function (str) {
...
40      if (alpha ? i++ : alpha = charInfo., alpha) { // <- this line
41        result += "&" + alpha + ";", i++;
42        continue;
43      }

Input Code

• package.json dependencies:

{
    "@babel/cli": "^7.8.4",
    "@babel/core": "^7.9.0",
    "@babel/preset-env": "^7.9.0",
    "@babel/preset-react": "^7.9.4",
    "@babel/preset-typescript": "^7.9.0",
    "babel-eslint": "^10.1.0",
    "babel-jest": "^25.2.1",
    "babel-loader": "^8.1.0",
    "babel-preset-minify": "^0.5.1",
    ...
}

Expected behavior/code
Should not convert subscription format into dot format when the key is an empty string.

charInfo[''] // => charInfo[''] instead of charInfo.

Babel Configuration (babel.config.js, .babelrc, package.json#babel, cli command, .eslintrc)

• Filename: babel.config.js

DEBUG = true;

module.exports = {
  // codegen options
  compact: !DEBUG,
  minified: !DEBUG,
  comments: DEBUG,
  sourceMaps: DEBUG,
  auxiliaryCommentBefore: '',
  auxiliaryCommentAfter: '',
  plugins: [],
  presets: [
    ['minify', {
      mangle: false,
      builtIns: false,
      removeConsole: false,
      removeDebugger: false,
    }],
    ['@babel/preset-env', {
      spec: false,
      modules: 'auto',
      targets: {
        node: true,
        browsers: [
          'last 2 chrome versions',
          'last 2 firefox versions',
        ],
      },
      useBuiltIns: false,
    }],
    ['@babel/preset-typescript', {
      isTSX: true,
      jsxPragma: 'React',
      allExtensions: true,
    }],
    ['@babel/preset-react', {
      pragma: 'React.createElement',
      pragmaFrag: 'React.Fragment',
      useBuiltIns: false,
      throwIfNamespace: true,
    }],
  ],
};

Environment

  System:
    OS: macOS 10.15.3
  Binaries:
    Node: 12.16.1 - ~/.nvm/versions/node/v12.16.1/bin/node
    npm: 6.14.3 - ~/.nvm/versions/node/v12.16.1/bin/npm
  npmPackages:
    @babel/cli: ^7.8.4 => 7.8.4 
    @babel/core: ^7.9.0 => 7.9.0 
    @babel/preset-env: ^7.9.0 => 7.9.0 
    @babel/preset-react: ^7.9.4 => 7.9.4 
    @babel/preset-typescript: ^7.9.0 => 7.9.0 
    babel-eslint: ^10.1.0 => 10.1.0 
    babel-jest: ^25.2.1 => 25.2.1 
    babel-loader: ^8.1.0 => 8.1.0 
    babel-preset-minify: ^0.5.1 => 0.5.1 
    eslint: ^6.8.0 => 6.8.0 
    jest: ^25.2.2 => 25.2.2 
    webpack: ^4.42.1 => 4.42.1 

• How you are using Babel: cli, babel-loader, both displays the same result
  Possible Solution
  Determine if key to an object is an empty string, if it is then it should not be converted to . (dot notation).

charInfo[''] // => charInfo[''] instead of charInfo.

Additional context/Screenshots
Add any other context about the problem here. If applicable, add screenshots to help explain.

[babel-bot]

Hey @copyrighthero! We really appreciate you taking the time to report an issue. The collaborators on this project attempt to help as many people as possible, but we're a limited number of volunteers, so it's possible this won't be addressed swiftly.

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