when you build your React project create-react-app
By default, files bundled by webpack and sourcemaps corresponding to those files are created.
sourcemap is file for debug
if the file exists, the compressed and obfuscated file can be viewed again in the browser as the original source.
Since the internal code is exposed as it is, all the benefits of obfuscation are lost. Projects that shouldn't be exposed can be fatal.
for large project ,
when you build , you create until sourcemap maybe you will happen out of memory phenomenon
In this case, setting the build so that it does not generate sourcemap can solve the problem.
You can set the environment variable GENERATE_SOURCEMAP to false. You can do this by adding GENERATE_SOURCEMAP=false to your .env file, but your personal preference is to modify package.json as follows
"build" : "GENERATE_SOURCEMAP=false react-scripts build"