Hard coding a URI makes it difficult to test a program: path literals are not always portable across operating systems, a given absolute path may
not exist on a specific test environment, a specified Internet URL may not be available when executing the tests, production environment filesystems
usually differ from the development environment, …etc. For all those reasons, a URI should never be hard coded. Instead, it should be replaced by
customizable parameter.
Further even if the elements of a URI are obtained dynamically, portability can still be limited if the path-delimiters are hard-coded.
This rule raises an issue when URI’s or path delimiters are hard coded.
Noncompliant Code Example
public class Foo {
public func listUsers() -> [User] {
var users:[User]
let location = "/home/mylogin/Dev/users.txt" // Non-Compliant
let fileContent = NSString(contentsOfFile: location, encoding: NSUTF8StringEncoding, error: nil)
users = parse(fileContent!)
return users
}
}
Compliant Solution
public class Foo {
// Configuration is a class that returns customizable properties: it can be mocked to be injected during tests.
private var config:Configuration
public init(myConfig:Configuration) {
config = myConfig
}
public func listUsers() -> [User] {
var users:[User]
// Find here the way to get the correct folder, in this case using the Configuration object
let location = config.getProperty("myApplication.listingFile")
// and use this parameter instead of the hard coded path
let fileContent = NSString(contentsOfFile: location, encoding: NSUTF8StringEncoding, error: nil)
users = parse(fileContent!)
return users
}
}
