179e9c610f
This replaces the integration test of `addSource` when duplicate identifiers are used in `MGLSourceTests` with a more direct unit test in the style class's unit test file `MGLStyleTests`. Although tests of the case where the same instance are actually integration tests where the source instance itself throws, it is easier to test all of this functionality in one place using the public facing MGLStyle API.
Darwin
The code in the Darwin platform targets Apple platforms but is not specific to iOS or macOS. This code is not distributed as an SDK in itself, but is required by the Mapbox iOS SDK and Mapbox macOS SDK.
These files depend on the Foundation and Core Foundation frameworks but do not depend on iOS- or macOS–specific frameworks, such as UIKit or AppKit. Any non-cross-platform code is guarded by TargetConditionals.h macros.