old_contents: const paths = require('./paths');
  const getClientEnvironment = require('./env');
  
  const publicPath = paths.publicUrlOrPath + 'assets/';
  // We will provide `paths.publicUrlOrPath` to our app
  // as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
  // Omit trailing slash as %PUBLIC_URL%/xyz looks better than %PUBLIC_URL%xyz.
  // Get environment variables to inject into our app.
  const env = getClientEnvironment(publicPath.slice(0, -1));
  
  const isEnvDevelopment = env.raw.NODE_ENV === 'development';
  const isEnvProduction = env.raw.NODE_ENV === 'production';
  const isEnvTest = env.raw.NODE_ENV === 'test';
  
  // Variable used for enabling profiling in Production
  // passed into alias object. Uses a flag if passed into the build commandF
  const isEnvProductionProfile = isEnvProduction && process.argv.includes('--profile');
  
  const imageInlineSizeLimit = parseInt(process.env.IMAGE_INLINE_SIZE_LIMIT || '10000');
  
  // Source maps are resource heavy and can cause out of memory issue for large source files.
  const shouldUseSourceMap = process.env.GENERATE_SOURCEMAP !== 'false';
  
  const isServerWebpackConfig = process.env.WEBPACK_SERVER_CONFIG;
  
  const isSSR = env.raw.REACT_APP_SSR === 'true';
  
  // Express port and host
  const port = process.env.PORT || 8080;
  const host = process.env.HOST || 'locahost';
  const ssl = process.env.SSL === 'true' || false;
  const logLevel = process.env.LOG_LEVEL;
  
  module.exports = {
    env,
    host,
    imageInlineSizeLimit,
    isEnvDevelopment,
    isEnvProduction,
    isEnvProductionProfile,
    isEnvTest,
    isSSR,
    isServerWebpackConfig,
    logLevel,
    port,
    publicPath,
    shouldUseSourceMap,
    ssl,
  };
  
new_contents: const paths = require('./paths');
  const getClientEnvironment = require('./env');
  
  const publicPath = paths.publicUrlOrPath + 'assets/';
  // We will provide `paths.publicUrlOrPath` to our app
  // as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
  // Omit trailing slash as %PUBLIC_URL%/xyz looks better than %PUBLIC_URL%xyz.
  // Get environment variables to inject into our app.
  const env = getClientEnvironment(publicPath.slice(0, -1));
  
  const isEnvDevelopment = env.raw.NODE_ENV === 'development';
  const isEnvProduction = env.raw.NODE_ENV === 'production';
  const isEnvTest = env.raw.NODE_ENV === 'test';
  
  // Variable used for enabling profiling in Production
  // passed into alias object. Uses a flag if passed into the build commandF
  const isEnvProductionProfile = isEnvProduction && process.argv.includes('--profile');
  
  const imageInlineSizeLimit = parseInt(process.env.IMAGE_INLINE_SIZE_LIMIT || '10000');
  
  // Source maps are resource heavy and can cause out of memory issue for large source files.
  const shouldUseSourceMap = process.env.GENERATE_SOURCEMAP !== 'false';
  
  const isServerWebpackConfig = process.env.WEBPACK_SERVER_CONFIG;
  
  const isSSR = env.raw.REACT_APP_SSR === 'true';
  
  // Express port and host
  const port = env.PORT;
  const host = process.env.HOST || 'locahost';
  const ssl = process.env.SSL === 'true' || false;
  const logLevel = process.env.LOG_LEVEL;
  
  module.exports = {
    env,
    host,
    imageInlineSizeLimit,
    isEnvDevelopment,
    isEnvProduction,
    isEnvProductionProfile,
    isEnvTest,
    isSSR,
    isServerWebpackConfig,
    logLevel,
    port,
    publicPath,
    shouldUseSourceMap,
    ssl,
  };
  
subject: fix heroku