[Swift] Xcode 10.2 and use of namespace causes compiler warnings.

[ileitch]

With Xcode 10.2, a warning is now emitted when a public class/struct exists within a public extension.

For example, using apollo codegen:generate --target=swift --namespace="MyNamespace" and the following generated code:

import Apollo

public extension MyNamespace {
  public final class MyQuery: GraphQLQuery {
  }

  public struct MyFragment: GraphQLFragment {
  }
}

Swift will emit the warning 'public' modifier is redundant for class declared in a public extension for the MyQuery class and MyFragment struct.

The solution is to simply not include the public modifier for MyQuery when using a namespace.

This is not a language change, just a new warning. The fix should be compatible with all versions of Swift 4.

Note that it's quite common for Swift projects to treat warnings as errors, so this bug is a blocker for us.

Versions

Apollo 2.8.1