How to write Jest transformIgnorePatterns

Question

I have this excpetion

Jest encountered an unexpected token

    This usually means that you are trying to import a file which Jest cannot parse, e.g. it\'s not p         


        

Answer 1

Actually, it seems like typescript is not going well with JEST test cases, so what i feel like either JEST need to ignore those files or those packages need to be transpiled to js code which JEST can understand,

you can try this

"transformIgnorePatterns": [ "node_modules/(?!(@microsoft/sp-core-library))" ],

and in tsconfig.json

"allowJs": true,

for more details please check this post

https://github.com/SharePoint/sp-dev-docs/issues/2325#issuecomment-446416878