feat(replace): typeofReplacements option

[guybedford]

Rollup Plugin Name: plugin-replace

This PR contains:

• bugfix
• feature
• refactor
• documentation
• other

Are tests included?

• yes (bugfixes and features will not be merged without tests)
• no

Breaking Changes?

• yes (breaking changes will not be merged unless absolutely necessary)
• no

Description

Currently process.env.NODE_ENV replacements only replace that exact string. But as came up in reactjs/react-transition-group#777, it can be useful for browser code to guard these replacements like:

if (typeof process !== 'undefined' && process.env.NODE_ENV === 'production') {...}

by default this plugin will not handle these other guards properly.

This PR adds a new typeofReplacements: true option (disabled by default, although it would be nice to enable by default in future), which will replace the typeof process with "object" in the case of identifier member expression replacement strings.

The user only needs to define process.env.NODE_ENV as the replacement key, and it will automatically expand the parent object typeof replacements when using this option.

See the README for a further example.

[guybedford]

It's very tricky to get these snapshots to line up when working on Windows. Everything is passing, but would be appreciated if someone with a unix machine could update the snapshots here. Alternatively when I next have access to WSL I can take a look.

Update: Finally got the snapshots updated over WSL on my other machine.

[shellscape]

The concept is sound. Not so sure about the option name. To anyone not familiar with the use case, I don't think the option name conveys what the option does.

[guybedford]

Thanks for the review @shellscape I've renamed the feature to objectGuards if that seems like a more descriptive name?

[shellscape]

Sounds good to me

[privatenumber]

@guybedford

Shouldn't typeof process be transformed to 'object'? :

if ('object' !== 'undefined' && "production" === 'production') {