Why do we need to pass --bundle-output even though the output is defined from within the webpack config?

[tom-sherman]

We specify output.path inside the webpack config, so why do we need to supply --bundle-output in to the webpack-bundle command?

Is it safe to supply a temporary directory here? If so, why not remove the need for the option in the CLI?

Related to #127

[zamotany]

--bundle-output is a destination for main bundle supplied by React Native when building with XCode or Gradle - without it we Re.Pack wouldn't know where to copy main bundle and the application ipa/apk would not include one, which would result in a crash. Additionally, if --assets-dest is not provided, the path will be inferred from --bundle-output.

When you're calling react-native webpack-bundle yourself, you could provide --bundle-output <whatever> and it will be all good. The reason why --bundle-output cannot be replaced with specifying output.path, is that on iOS the path is pointing into internal directories with UUID-like segments, so it's not easy to guess where it will be.

Another argument, is that webpack-bundle is modelled after bundle command from React Native CLI - we want webpack-bundle to have the same syntax and be a drop-in replacement.