Update history and imports in test code

[toranb]

I wanted to update the imports I found in test code (and the dependency itself)

[taion]

Per https://github.com/rackt/history/blob/master/docs/GettingStarted.md#minimizing-your-build you actually shouldn't import history that way, so I believe what we have there is intentional.

We also don't really get anything from updating the dev dependency since the semver range still matches the current version.

[toranb]

Understood - quick comment about the link you sent over => it seems to be about minimizing your build size (is this required/ the most important thing for test code) ?

[taion]

It doesn't matter at all for test code - it's just defensive against people seeing us use a particular pattern in test code and copying it in their own code.

Same reason we do e.g. https://github.com/rackt/react-router/blob/4bea5c1143c44cc5b4019d0954627696b3ff0d70/modules/__tests__/Router-test.js#L288. That's an awful way to write that code v. binding in render or something, but it's just defensive as a potential example.

The only time you can safely import stuff like that is when you're using an ES6-module-aware bundler that can do tree shaking... this is basically just rollup (not really suitable for applications) or webpack 2 (last I checked babel-loader didn't work there yet, so not really suitable for React anything).

And only for packages that have an ES6 module build... which history will on the next release assuming my change adding that build doesn't get backed out per #2530 (comment).

You okay with closing this?