Temporary hack to fix terser output #5461
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Feiyang1
reviewed
Sep 8, 2021
| // bundlers (Babel?) to confuse the same variable name in different scopes. | ||
| // This can be removed if the problem in the downstream library is fixed | ||
| // or if terser's mangler provides an option to avoid mangling everything | ||
| // that isn't a property. |
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probably worth adding the issue link for future reference.
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We have two lists of reserved properties now (see right below - line 158). Do we know that this will work?
Feiyang1
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Sep 8, 2021
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Mangled terser code is causing some problems seen in Create React App apps. This is a temporary fix that will avoid mangling the specific variable in question. Long term fix is to see if terser will provide an option to mangle properties without mangling anything else (currently not available), and/or find out what downstream build tool is causing this bug and get them to fix it.
Details:
The
initializeFirestore()function, when mangled by terser, has two variables with the same name in different scopes (one is an import, one is aconstin anifblock). This seems to confuse one of the tools in the Create React App production default build pipeline (Babel?). The code is converted to ES5, which makes theconstavar, which puts both variables sharing a name into the same scope. The build tool gets confused and does not convert the import to the correct symbol, thinking it is the same as the declaredvar. We should try to pinpoint what step of the build this happens in and report a bug to the appropriate library.Fixes #5384