Enable esModule by default

[edmorley]

• Operating System: N/A
• Node Version: N/A
• NPM Version: N/A
• webpack Version: 4
• mini-css-extract-plugin Version: 0.9.0

Expected Behavior / Situation

The esModule option is enabled by default.

Actual Behavior / Situation

The esModule option is not enabled by default.

Modification Proposal

In #475 a new esModule loader option was added, which causes the loader part of mini-css-extract-plugin to output ES Module style syntax instead of CJS (docs).

Currently the feature is disabled by default, and to gain the benefits (eg improved tree shaking), people have to enable it explicitly by setting it to true.

I propose enabling it by default, so that:

1. People don't have to know about the feature to gain the benefits (not everyone will read about it/understand the benefits)
2. Reduce the amount of webpack config boilerplate when using mini-css-extract-plugin

Since webpack 4 already natively supports ES Modules, and mini-css-extract-plugin only supports webpack 4 or newer, it seems this could land as a feature change rather than a breaking change, though I'd be fine with either, so long as we can enable it by default :-)

[alexander-akait]

It will be enable by default for next version

[edmorley]

I don't know if you saw (I couldn't tell from your message wording?), but I already opened a PR to make the switch (#486) :-)

[alexander-akait]

Fixed #602, release will be today