Merge pull request MakeAWishFoundation#257 from MakeAWishFoundation/argument-captor-filter

add optional filter for values captured by ArgumentCaptor

Author: TimeDelta

Sources/SwiftyMocky/ArgumentCaptor.swift

@@ -9,8 +9,15 @@ public class ArgumentCaptor<Type> {
 	public init() {}
 
 	/// Return parameter matcher which captures the argument.
-	public func capture() -> Parameter<Type> {
+	public func capture(where matches: ((Type) -> Bool)? = nil) -> Parameter<Type> {
 		return .matching({ (value: Type) -> Bool in
+			if let matchFunction = matches {
+				let match = matchFunction(value)
+				if match {
+					self.allValues.append(value)
+				}
+				return match
+			}
 			self.allValues.append(value)
 			return true
 		})