Does not correctly indicate the path to the file

[vasivas]

// index.ts

console.log('is src/index.ts');
nonExistenFunction();

is src/index.ts context.js:2509
index.ts:2 Uncaught ReferenceError: nonExistenFunction is not defined index.ts:2
at Object../index.ts (index.ts:2)
at webpack_require (index.ts:2)
at Object../index.spec.ts (index.ts:2)
at webpack_require (index.ts:2)
at index.ts:2
at index.ts:2

The sourcemap has applied to the error path and therefore the path is specified in the browser console as index.ts. It's Ok!
But the console.log path is specified as context.js. It's Bad!

How to make the console.log path in the browser display index.ts?

Minimal configuration of the project https://github.com/vasivas/karma-webpack-demo