Webpack/babel/react - "uncaught Syntaxerror: Unexpected Token :"

I have a webpack-dev-server running that compiles and serves some Babel/React code. I have gotten as far as to have it serve the compiled client.js over localhost:3001. But when I

Solution 1:

I was using webpack's DefinePlugin to set process.env.BABEL_ENV like this:

newDefinePlugin({
  'process.env': {
    BABEL_ENV: JSON.stringify('client')
  }
});

This resulted in webpack replacing all instances of process.env in the code with {"BABEL_ENV":"client"}. The SyntaxError was caused in this part, not in the ternary expression.

I fixed it by setting process.env.BABEL_ENV like this:

newDefinePlugin({
  'process.env.BABEL_ENV': JSON.stringify('client')
});