How to mock ProcessInfo?

[xareelee]

I want to make ProcessInfo.processInfo.environment[key] return specific values when testing.

How can I achieve that with Cuckoo? It's hard to find a sample code. Most of them use dependency injection with adopting protocols.

[MatyasKriz]

Hey, @xareelee. Cuckoo depends on having the source code on hand to generate the mocking classes as needed. ProcessInfo might be mockable using the OCMock integration, so take a look at the tests and try that.

[mugabe]

You can do it in swifty way without OCMock.

At first, to keep your code testable you should not use ProcessInfo.processInfo directly, but pass it as dependency to your class. e.g.:

class App {
    init(processInfo: ProcessInfo) {
        if (processInfo.environment["help"] != nil) {
            printHelp()
        }
    }
}
App(processInfo: ProcessInfo.processInfo)

Then you can describe your own protocol that ProcessInfo should conform.

protocol ProcessInfoProtocol {
    var environment: [String : String] { get }
}
extension ProcessInfo: ProcessInfoProtocol { }

Now you can replace dependency type of your class to ProcessInfoProtocol and pass own implementation or Cuckoo's mock.