Transpilation in v16.1.0 freezes the react-dom/server interface

[travi]

As initially reported in #11520 (comment), attempting to upgrade from v16.0 to v16.1 caused a test that was previously working to fail. The test was using sinon to stub renderToStaticMarkup on react-dom/server and v16.1 results in the following error:

TypeError: Cannot redefine property: renderToStaticMarkup
    at Function.defineProperty (<anonymous>)
    at wrapMethod (node_modules/sinon/lib/sinon/util/core/wrap-method.js:92:16)
    at stub (node_modules/sinon/lib/sinon/stub.js:60:44)
    at Object.stub (node_modules/sinon/lib/sinon/collection.js:102:33)
    at Context.setup (test/unit/....)

the export from react-dom/cjs/react-dom-server.node.development is frozen as:

Object.freeze({
  renderToString: renderToString,
  renderToStaticMarkup: renderToStaticMarkup,
  renderToNodeStream: renderToNodeStream,
  renderToStaticNodeStream: renderToStaticNodeStream,
  version: version
});

the source is not frozen, and #11520 (comment) further confirms that the Object.freeze() is a result of the transpilation.

for now, i am simply splitting this report into a separate issue from #11520, but i will add a reproduction soon and plan to submit a PR as a follow up.

[travi]

a reproduction is available at https://github.com/travi/react-dom-frozen

[gaearon]

Here is how to fix it: #11520 (comment)

Happy to take a PR for this.

[travi]

I hope to put a PR together for this sometime today/tonight. I just ran out of time last night

[gaearon]

So, I'm not super happy with this solution, but it seems easier to do this now and maybe break this in 17.

Longer term I would encourage you to use mocking solutions that don't require monkeypatching public APIs, if possible. This would break when Node ships ES modules and React offers an ES module version anyway.