When users see errors like
```
Duplicate plugin/preset detected.
If you'd like to use two separate instances of a plugin,
they need separate names, e.g.
plugins: [
['some-plugin', {}],
['some-plugin', {}, 'some unique name'],
]
```
It can be difficult to determine the source of the conflict, especially
in a larger build system.
This commit outputs what is known about the plugins that actually
conflict, which can be helpful for users to determine the root cause of
the conflict.
Partially addresses #9778
Instead of using `convert-source-map`'s `removeComments` method before
parsing the file, we can first parse the file with `@babel/parser` and then
analyze the comments.
This is needed because it is not possible to reliabily detect comments in
JavaScript without fully parsing the file:
https://github.com/thlorenz/convert-source-map/issues/63
* Fixed null error in plugin opts and added a test for it
* Remove !opts and add opts === null check to avoid confusion with false and undefined cases
Co-Authored-By: divbhasin <divbest99@gmail.com>
* Fix running flow on travis and update flow
- ensure bootstrap is run before running flow as we need some generated files for correctly doing typechecks
- ensure that we only ignore the build directory inside the babel folder as currently we ignore everything because travis checks out into ‘/home/travis/build/’
* Fix all flow errors
These are now enabled by default:
- objectRestSpread (2018)
- asyncGenerators (2018)
- optionalCatchBInding (2019)
- jsonStrings (2019)
TODO (after this commit):
- [ ] Deprecate the `@babel/plugin-syntax-*` packages.
- [ ] Deprecate the `@babel/plugin-proposal-*` packages.
- [ ] Create the `@babel/plugin-transform-*` packages.
Previously, if the optional `opts` parameter wasn't passed, the _intent_ was to move the function it held into the `callback` parameter and null out the `opts` param - but instead, it was nulling both.
| Q | A <!--(Can use an emoji 👍) -->
| ------------------------ | ---
| Fixed Issues? | Fixes https://github.com/babel/babel-loader/issues/642
| Patch: Bug Fix? | Y
| Major: Breaking Change? | N
| Minor: New Feature? |
| Tests Added + Pass? | Yes
| Documentation PR Link | <!-- If only readme change, add `[skip ci]` to your commits -->
| Any Dependency Changes? |
| License | MIT
Since these were getting left in, things that loaded the config, and then passed in back to Babel would get `test` and such _twice_, which could lead to either bad configuration merging, or no configuration at all if the patterns were relative to different directories, as was the case in https://github.com/babel/babel-loader/issues/642.
