Rewire API added to module twice

[mbfisher]

A contrived example:

MyClass.js

export default class MyClass {
}

index.js

const MyClass = require('./MyClass');
MyClass.foo = 'bar';

export default MyClass;

This leads to an error whereby __Rewire__ is added to the MyClass export in MyClass.js and index.js, causing Object.defineProperty to fail the second time around:

Object.defineProperty(_defaultExport, '__Rewire__', {
    'value': __Rewire__,
    'enumberable': false
});

I'd love have a go at a PR for this but have never worked with the Babel internals and it looks a bit mad...

M

[TheSavior]

Interesting. I'd imagine this could be a problem with any of the rewire flavors. I recently ran into this error with rewire-global but didn't look into it yet. Any module that just exports one of its dependencies exports would have this problem.

@i-like-robots, have you come across this? @jhnns, perhaps we should be adding a check that these functions don't already exist in https://github.com/jhnns/rewire/blob/master/lib/getDefinePropertySrc.js

This is further reason why we should figure out how to be sharing all this code between all these modules ala i-like-robots/rewireify#17

[mbfisher]

I have a commit which fixes my instance of this. I've been able to test the changes in exit but not in ExportDefaultDeclaration. I've never worked with the Babel API before - is it along the right lines?

M

[speedskater]

@mbfisher thanks for reporting this issue and creating the PR. Your issue is resolved by #62.

Generally patterns like in your sample were an existing class is changed and then reexported should be avoided, as this always modifies the original class. If this is intended and you want to be able to rewire the modified as well as the original module it is recommended to use the RewireApi object.

[mbfisher]

Cheers!

M

On Thursday, 1 October 2015, speedskater notifications@github.com wrote:

@mbfisher https://github.com/mbfisher thanks for reporting this issue
and creating the PR. Your issue is resolved by #62
#62.

Generally patterns like in your sample were an existing class is changed
and then reexported should be avoided, as this always modifies the original
class. If this is intended and you want to be able to rewire the modified
as well as the original module it is recommended to use the RewireApi
object.

—
Reply to this email directly or view it on GitHub
#57 (comment)
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Mike Fisher

Email: mike@mbfisher.com
Skype: mb_fisher
GitHub: mbfisher