code transpilation is not performed for imported modules when prevaling with template literals

[marzelin]

• babel-plugin-preval version: ^1.6.3
• node version: ^9
• npm (or yarn) version: ^1

Great tool, thanks for it. There's one thing though: when the code to be prevaled in template tags requires a module, that module won't be transpiled by babel. For example, this code that prerenders a react element:

const markupForElement = preval`
   const render = require("react-dom/server").renderToStaticMarkup;
   const reactElement = require("./reactElement");
   module.exports = render(reactElement);
`

will fail with error:

Module build failed: .../reactElement.js:2
const reactElement = <div>Hello from React Element</div>;
                     ^

SyntaxError: Unexpected token <

even though react preset is added to babel configuration.

The simplest solution is to add require("babel-register"); at the top of a template literal. However, it would be nice if this package could handle this automatically.

Suggested solution:
Prepend transpiled with "require("babel-register");\n" before passing it to requireFromString at

babel-plugin-preval/src/get-replacement.js

Line 10 in 36de84a

const val = requireFromString(transpiled, filename)

[kentcdodds]

Sounds awesome 👍 Yes, I'd happily accept a PR that does this 👍