Errors are not wrapped with %w

[marc-harrison]

Errors like:

return Flags{}, &FlagsmithAPIError{msg: fmt.Sprintf("flagsmith: error performing request to Flagsmith API: %s", err)}

Are not wrapped with %w e.g.

return Flags{}, &FlagsmithAPIError{msg: fmt.Sprintf("flagsmith: error performing request to Flagsmith API: %w", err)}

This makes handling errors like -

  Failed to fetch flags with error:
    flagsmith:
      error performing request to Flagsmith API:
        Post "https://api.flagsmith.com/api/v1/identities/":
          context deadline exceeded (Client.Timeout exceeded while awaiting headers)

a challenge. I'm happy to make a PR there's 5 places.

[gagantrivedi]

@marc-harrison Yep, a PR would be great!

[gagantrivedi]

Thinking about this a bit more: simply replacing %v with %w will not work because the error struct expects a string for msg field and not error.

What we do need to do is basically rewrite the whole error handling here, but that will mean a major version change