OperatingSystem constructor

@visibleForTesting OperatingSystem(String id, String version)

Creates a new operating system object for testing.

Can be used with overrideOperatingSystem to selectively change the value returned by current.

Notice: Using this constructor may reduce the efficiency of compilers recognizing code that isn't needed when compiling for a particular platform (aka. "tree-shaking" of unreachable code).

Implementation

// Uses chained conditionals to allow back-ends to constant fold when they
// know what `id` is, which they'd usually know for a specific operation.
// That can avoid retaining *all* the subclasses of `OS`.
@visibleForTesting
@pragma('vm:prefer-inline')
OperatingSystem(String id, String version)
    : this._(
          id == linuxId
              ? const LinuxOS()
              : id == macOSId
                  ? const MacOS()
                  : id == windowsId
                      ? const WindowsOS()
                      : id == androidId
                          ? const AndroidOS()
                          : id == iOSId
                              ? const IOS()
                              : id == fuchsiaId
                                  ? const FuchsiaOS()
                                  : id == browserId
                                      ? const BrowserOS()
                                      : UnknownOS(id),
          version);