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Should babelHelpers be `runtime` ?

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
35/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Stale
Tech stack
babel, javascript, rollup

Research direction

Start by tracing where microbundle configures Babel helpers and compare its current bundled setting with Rollup's documented runtime option. Determine whether runtime helpers can be configured and whether runtime should become the default for library builds; done means the behavior is implemented or clearly documented, with the relevant configuration and compatibility implications covered.

Written by the indexing model from the issue text.

Description

discussion

In rollup's documentation, there the following excerpt:

'runtime' - you should use this especially when building libraries with Rollup. It has to be used in combination with @babel/plugin-transform-runtime and you should also specify @babel/runtime as dependency of your package. Don't forget to tell Rollup to treat the helpers imported from within the @babel/runtime module as external dependencies when bundling for cjs & es formats. This can be accomplished via regex (external: [/@babel/runtime/]) or a function (external: id => id.includes('@babel/runtime')). It's important to not only specify external: ['@babel/runtime'] since the helpers are imported from nested paths (e.g @babel/runtime/helpers/get) and Rollup will only exclude modules that match strings exactly.

I've noticed microbundle uses bundled option... is there any way to change/configure this? And should microbundle use runtime by default, given that it focuses in library bundling?

Dominant language
JavaScript
Stars
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Forks
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