Do not merge commonJS exports into an alias #28133
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getCommonJSExportEquals merges export assignments and export property
assignments. Something like this, which has no equivalent structure in
TS:
```js
module.exports = function() { }
module.exports.expando = 1
```
However, it is sometimes called with an alias, when its
parent, resolveExternalModuleSymbol, is called with dontResolveAlias:
true, and when the initialiser of the export assignment is an alias:
```js
function alias() { }
module.exports = alias
module.exports.expando = 1
```
In this case, (1) the actual value `alias` will have already merged in a
previous call to getCommonJSExportEquals and
(2) getTypeOfSymbol will follow the alias symbol to get the right type.
So getCommonJSExportEquals should do nothing in this case.
This bug manifests in the code for dynamic imports, which calls
getTypeOfSymbol on the incorrectly merged alias, which now has enough
value flags--Function, for example--to take the wrong branch and
subsequently crash.
sandersn
changed the title
ghost
approved these changes
Oct 25, 2018
|
Potentially related: #27857 |
This was referenced Nov 1, 2018
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getCommonJSExportEquals merges export assignments and export property assignments. Something like this, which has no equivalent structure in TS:
However, it is sometimes called with an alias, when its parent, resolveExternalModuleSymbol, is called with dontResolveAlias: true, and when the initialiser of the export assignment is an alias:
In this case, (1) the actual value
aliaswill have already merged in a previous call to getCommonJSExportEquals and (2) getTypeOfSymbol will follow the alias symbol to get the right type. So getCommonJSExportEquals should do nothing in this case.This bug manifests in the code for dynamic imports, which calls getTypeOfSymbol on the incorrectly merged alias, which now has enough value flags--Function, for example--to take the wrong branch and subsequently crash.
Fixes #28014