Latest 2.2.4
Homepage https://github.com/Rivukis/Spry
License MIT
Platforms ios 9.0
Dependencies Nimble, Spry
Frameworks XCTest
Authors

TODO: Build example project.

Spry

Version
License
Platform

Spry is a framework that allows spying and stubbing in Apple’s Swift language. Also included is a Nimble matcher for the spied objects.

Table of Contents

Motivation

When writing tests for a class, it is advised to only test that class’s behavior and not the other objects it uses. With Swift this can be difficult.

How do you check if you are calling the correct methods at the appropriate times and passing in the appropriate arguments? Spry allows you to easily make a spy object that records every called function and the passed-in arguments.

How do you ensure that an injected object is going to return the necessary values for a given test? Spry allows you to easily make a stub object that can return a specific value.

This way you can write tests from the point of view of the class you are testing (the subject under test) and nothing more.

Spryable

Conform to both Stubbable and Spyable at the same time! For information about Stubbable and Spyable see their respective sections below.

Abilities

  • Conform to Spyable and Stubbable at the same time.
  • Reset calls and stubs at the same time with resetCallsAndStubs()
  • Easy to implement
    • Create an object that conforms to Spryable
    • In every function (the ones that should be stubbed and spied) return the result of spryify() passing in all arguments (if any)
      • also works for special functions like subscript
    • In every property (the ones that should be stubbed and spied) return the result of stubbedValue() in the get {} and use recordCall() in the set {}

Spryable Example

// The Real Thing can be a protocol
protocol StringService: class {
    var readonlyProperty: String { get }
    var readwriteProperty: String { set get }
    func giveMeAString(arg1: Bool, arg2: String) -> String
    static func giveMeAString(arg1: Bool, arg2: String) -> String
}

// The Real Thing can be a class
class StringService {
    var readonlyProperty: String {
        return ""
    }

    var readwriteProperty: String = ""

    func giveMeAString(arg1: Bool, arg2: String) -> String {
        // do real things
        return ""
    }

    static func giveMeAString(arg1: Bool, arg2: String) -> String {
        // do real things
        return ""
    }
}

// The Fake Class (If the fake is from a class then `override` will be required for each function and property)
class FakeStringService: StringService, Spryable {
    enum StaticFunction: String, StringRepresentable { // <-- **REQUIRED**
        case giveMeAString = "giveMeAString(arg1:arg2:)"
    }

    enum Function: String, StringRepresentable { // <-- **REQUIRED**
        case readonlyProperty = "readonlyProperty"
        case readwriteProperty = "readwriteProperty"
        case giveMeAString = "giveMeAString(arg1:arg2:)"
    }

    var readonlyProperty: String {
        return stubbedValue()
    }

    var readwriteProperty: String {
        set {
            recordCall(arguments: newValue)
        }
        get {
            return stubbedValue()
        }
    }

    func giveMeAString(arg1: Bool, arg2: String) -> String {
        return spryify(arguments: arg1, arg2) // <-- **REQUIRED**
    }

    static func giveMeAString(arg1: Bool, arg2: String) -> String {
        return spryify(arguments: arg1, arg2) // <-- **REQUIRED**
    }
}

Stubbable

Conforming to Spryable will conform to Stubbable and Spyable at the same time.

Abilities

  • Stub a return value for a function on an instance of a class or the class itself using .andReturn()
  • Stub a the implementation for a function on an instance of a class or the class itself using .andDo()
  • Specify stubs that only get used if the right arguments are passed in using .with() (see Argument Enum for alternate specifications)
  • Rich fatalError() messages that include a detailed list of all stubbed functions when no stub is found (or the arguments received didn’t pass validation)
  • Reset stubs with resetStubs()
  • Easy to implement
    • Create an object that conforms to Stubbable
    • In every function (the ones that should be stubbed) return the result of stubbedValue() passing in all arguments (if any)

When stubbing a function that doesn’t have a return value use Void() as the stubbed return value

Stubbable Example

// The Real Thing can be a protocol
protocol StringService: class {
    var readonlyProperty: String { get }
    var readwriteProperty: String { set get }
    func giveMeAString() -> String
    func hereAreTwoStrings(string1: String, string2: String) -> Bool
    func iHaveACompletionClosure(string: String, completion: () -> Void)
    static func imAStaticFunction()
}

// The Real Thing can be a class
class StringService {
    var readonlyProperty: String {
        return ""
    }

    var readwriteProperty: String = ""

    func giveMeAString() -> String {
        // do real things
        return "string"
    }

    func hereAreTwoStrings(string1: String, string2: String) -> Bool {
        // do real things
        return true
    }

    func iHaveACompletionClosure(string: String, completion: () -> Void) {
        // do real things
    }

    static func imAStaticFunction() {
        // do real things
    }
}

// The Stub Class (If the fake is from a class then `override` will be required for each function and property)
class FakeStringService: StringService, Stubbable {
    enum StaticFunction: String, StringRepresentable { // <-- **REQUIRED**
        case imAStaticFunction = "imAStaticFunction()"
    }

    enum Function: String, StringRepresentable { // <-- **REQUIRED**
        case readonlyProperty = "readonlyProperty"
        case readwriteProperty = "readwriteProperty"
        case giveMeAString = "giveMeAString()"
        case hereAreTwoStrings = "hereAreTwoStrings(string1:string2:)"
    }

    var readonlyProperty: String {
        return stubbedValue()
    }

    var readwriteProperty: String {
        get {
            return stubbedValue()
        }
    }

    func giveMeAString() -> String {
        return stubbedValue() // <-- **REQUIRED**
    }

    func hereAreTwoStrings(string1: String, string2: String) -> Bool {
        return stubbedValue(arguments: string1, string2) // <-- **REQUIRED**
    }

    func iHaveACompletionClosure(string: String, completion: () -> Void) {
        return stubbedValue(arguments: string, completion) // <-- **REQUIRED**
    }

    static func imAStaticFunction() {
        return stubbedValue() // <-- **REQUIRED**
    }
}

Stubbing Example

// will always return `"stubbed value"`
fakeStringService.stub(.hereAreTwoStrings).andReturn("stubbed value")

// specifying all arguments (will only return `true` if the arguments passed in match "first string" and "second string")
fakeStringService.stub(.hereAreTwoStrings).with("first string", "second string").andReturn(true)

// using the Arguement enum (will only return `true` if the second argument is "only this string matters")
fakeStringService.stub(.hereAreTwoStrings).with(Argument.anything, "only this string matters").andReturn(true)

// using custom validation
let customArgumentValidation = Argument.pass({ actualArgument -> Bool in
    let passesCustomValidation = // ...
    return passesCustomValidation
})
fakeStringService.stub(.hereAreTwoStrings).with(Argument.anything, customArgumentValidation).andReturn("stubbed value")

// using argument captor
let captor = Argument.captor()
fakeStringService.stub(.hereAreTwoStrings).with(Argument.nonNil, captor).andReturn("stubbed value")
captor.getValue(as: String.self) // gets the second argument the first time this function was called where the first argument was also non-nil.
captor.getValue(at: 1, as: String.self) // // gets the second argument the second time this function was called where the first argument was also non-nil.

// using `andDo()` - Also has the ability to specify the arguments!
fakeStringService.stub(.iHaveACompletionClosure).with("correct string", Argument.anything).andDo({ arguments in
    // get the passed in argument
    let completionClosure = arguments[0] as! () -> Void

    // use the argument
    completionClosure()

    // return an appropriate value
    return Void() // <-- will be returned by the stub
})

// can stub static functions as well
FakeStringService.stub(.imAStaticFunction).andReturn(Void())

Spyable

Conforming to Spryable will conform to Stubbable and Spyable at the same time.

Abilities

  • Test whether a function was called or a property was set on an instance of a class or the class itself
  • Specify the arguments that should have been received along with the call (see Argument Enum for alternate specifications)
  • Rich Failure messages that include a detailed list of called functions and arguments
  • Reset calls with resetCalls()
  • Easy to implement
    • Create an object that conforms to Spyable
    • In every function (the ones that should be spied) call recordCall() passing in all arguments (if any)

When using a protocol to declare the interface for an object, the compiler will tell you if/when the ‘fake’ doesn’t conform.

Spyable Example

// The Real Thing can be a protocol
protocol StringService: class {
    var readonlyProperty: String { get }
    var readwriteProperty: String { set get }
    func giveMeAString() -> String
    func hereAreTwoStrings(string1: String, string2: String) -> Bool
    static func imAStaticFunction()
}

// The Real Thing can be a class
class RealStringService: StringService {
    var readonlyProperty: String {
        return ""
    }

    var readwriteProperty: String = ""

    func giveMeAString() -> String {
        // do real things
        return "string"
    }

    func hereAreTwoStrings(string1: String, string2: String) -> Bool {
        // do real things
        return true
    }

    static func imAStaticFunction() {
        // do real things
    }
}

// The Spy Class (If the fake is from a class then `override` will be required for each function and property)
class FakeStringService: StringService, Spyable {
    enum StaticFunction: String, StringRepresentable { // <-- **REQUIRED**
        case imAStaticFunction = "imAStaticFunction()"
    }

    enum Function: String, StringRepresentable { // <-- **REQUIRED**
        case readwriteProperty = "readwriteProperty"
        case giveMeAString = "giveMeAString()"
        case hereAreTwoStrings = "hereAreTwoStrings(string1:string2:)"
    }

    var readonlyProperty: String {
        return ""
    }

    var readwriteProperty: String {
        set {
            recordCall(arguments: newValue)
        }
        get {
            return ""
        }
    }

    func giveMeAString() -> String {
        recordCall() // <-- **REQUIRED**
        return ""
    }

    func hereAreTwoStrings(string1: String, string2: String) -> Bool {
        recordCall(arguments: string1, string2) // <-- **REQUIRED**
        return false
    }

    static func imAStaticFunction() {
        recordCall() // <-- **REQUIRED**
    }
}

Did Call Example

The Result

// the result
let result = spyable.didCall(.functionName)

// was the function called on the fake?
result.success

// what was called on the fake?
result.recordedCallsDescription

How to Use

// passes if the function was called
fake.didCall(.functionName).success

// passes if the function was called a number of times
fake.didCall(.functionName, countSpecifier: .exactly(1)).success

// passes if the function was called at least a number of times
fake.didCall(.functionName, countSpecifier: .atLeast(1)).success

// passes if the function was called at most a number of times
fake.didCall(.functionName, countSpecifier: .atMost(1)).success

// passes if the function was called with equivalent arguments
fake.didCall(.functionName, withArguments: ["firstArg", "secondArg"]).success

// passes if the function was called with arguments that pass the specified options
fake.didCall(.functionName, withArguments: [Argument.nonNil, Argument.anything, "thirdArg"]).success

// passes if the function was called with an argument that passes the custom validation
let customArgumentValidation = Argument.pass({ argument -> Bool in
    let passesCustomValidation = // ...
    return passesCustomValidation
})
fake.didCall(.functionName, withArguments: [customArgumentValidation]).success

// passes if the function was called with equivalent arguments a number of times
fake.didCall(.functionName, withArguments: ["firstArg", "secondArg"], countSpecifier: .exactly(1)).success

// passes if the property was set to the right value
fake.didCall(.propertyName, with: "value").success

// passes if the static function was called
Fake.didCall(.functionName).success

Have Received Matcher

Have Received Matcher is made to be used with Nimble. This matcher is part of a separate cocoapod called ‘Spry+Nimble’. See below for installation.

All Call Matchers can be used with to() and toNot()

Have Received Example

// passes if the function was called
expect(fake).to(haveReceived(.functionName)

// passes if the function was called a number of times
expect(fake).to(haveReceived(.functionName, countSpecifier: .exactly(1)))

// passes if the function was called at least a number of times
expect(fake).to(haveReceived(.functionName, countSpecifier: .atLeast(2)))

// passes if the function was called at most a number of times
expect(fake).to(haveReceived(.functionName, countSpecifier: .atMost(1)))

// passes if the function was called with equivalent arguments
expect(fake).to(haveReceived(.functionName, with: "firstArg", "secondArg"))

// passes if the function was called with arguments that pass the specified options
expect(fake).to(haveReceived(.functionName, with: Argument.nonNil, Argument.anything, "thirdArg"))

// passes if the function was called with an argument that passes the custom validation
let customArgumentValidation = Argument.pass({ argument -> Bool in
    let passesCustomValidation = // ...
    return passesCustomValidation
})
expect(fake).to(haveReceived(.functionName, with: customArgumentValidation))

// passes if the function was called with equivalent arguments a number of times
expect(fake).to(haveReceived(.functionName, with: "firstArg", "secondArg", countSpecifier: .exactly(1)))

// passes if the property was set to the specified value
expect(fake).to(haveReceived(.propertyName, with "value"))

// passes if the static function was called
expect(Fake).to(haveReceived(.functionName))

// passes if the static property was set
expect(Fake).to(haveReceived(.propertyName))

SpryEquatable

Spry uses SpryEquatable protocol to equate arguments

  • Make types conform to SpryEquatable using only a single line to declare conformance and one of the following
    • Be AnyObject
      • all classs are AnyObject
      • enums and structs are NOT AnyObject
    • Conform to swift’s Equatable Protocol
      • To make custom types conform to Equatable, see Apple’s Documentation: Equatable
      • NOTE: If you forget to conform to Equatable, the compiler will only tell you that you are not conforming to SpryEquatable (You should never implement methods declared in SpryEquatable)
  • NOTE: Object’s, that are both AnyObject and conform to Equatable, will use pointer comparision and not Equatable‘s’ ==(lhs:rhs:) function.

Defaulted Conformance List

  • Optional (will fatalError() at runtime if the wrapped type does not conform to SpryEquatable)
  • String
  • Int
  • Double
  • Bool
  • Array
  • Dictionary
  • NSObject

SpryEquatable Conformance Example

// custom type
extension Person: Equatable, SpryEquatable {
    public state func == (lhs: Person, rhs: Person) -> Bool {
        return lhs.name == rhs.name
            && lhs.age == rhs.age
    }
}

// existing type that is already Equatable
extension String: SpryEquatable {}

ArgumentEnum

Use when the exact comparison of an argument using the Equatable protocol is not desired, needed, or possible.

  • case anything
    • Used to indicate that absolutly anything passed in will be sufficient.
  • case nonNil
    • Used to indicate that anything non-nil passed in will be sufficient.
  • case nil
    • Used to indicate that only nil passed in will be sufficient.
  • case pass((Any?) -> Bool)
    • Used to provide custom validation for a specific argument
  • func captor() -> ArgumentCaptor

ArgumentCaptor

ArgumentCaptor is used to capture a specific argument when the stubbed function is called. Afterward the captor can serve up the captured argument for custom argument checking. An ArgumentCaptor will capture the specified argument everytime the stubbed function is called.

Captured arguments are stored in chronological order for each function call. When getting an argument you can specify which argument to get (defaults to the first time the function was called)

When getting a captured argument the type must be specified. If the argument can not be cast as the type given then a fatalError() will occur.

ArgumentCaptor Example:

let captor = Argument.captor()
fakeStringService.stub(.hereAreTwoStrings).with(Argument.anything, captor).andReturn("stubbed value")

_ = fakeStringService.hereAreTwoStrings(string1: "first arg first call", string2: "second arg first call")
_ = fakeStringService.hereAreTwoStrings(string1: "first arg second call", string2: "second arg second call")

let secondArgFromFirstCall = captor.getValue(as: String.self) // `at:` defaults to `0` or first call
let secondArgFromSecondCall = captor.getValue(at: 1, as: String.self)

Xcode Template

A Template for creating fakes can be found in this repository in the "Templates" folder.

Usage

When you go to create a new file in Xcode, you will notice a new section called "Spry" with a template called "Spry Fake". Select the template, click "Next", enter the name of the type or protocol you want to fake (the word "Fake" will be added automatically), select the target(s) and folder location for the fake, and start testing!

Template Installation

In terminal run the following command:

svn export https://github.com/Rivukis/Spry/trunk/Templates/Spry ~/Library/Developer/Xcode/Templates/File Templates/Spry

Installation

Spry and Spry+Nimble are available through CocoaPods. To install, simply add them your Podfile.

platform :ios, '9.0'

source 'https://github.com/CocoaPods/Specs.git'

use_frameworks!

target "<YOUR_TARGET>" do
    target '<YOUR_TARGET>Tests' do
        inherit! :search_paths

        pod 'Spry'

        #Uncomment the following lines to import Quick/Nimble as well as a Nimble Matcher used to test if a 'fake' has received function calls.
        #pod 'Quick'
        #pod 'Nimble'
        #pod 'Spry+Nimble'
    end
end

Contributing

If you have an idea that can make Spry better, please don’t hesitate to submit a pull request!

License

MIT License

Copyright (c) [2017] [Brian Radebaugh]

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

Latest podspec

{
    "name": "Spry+Nimble",
    "version": "2.2.4",
    "summary": "Nimble matcher for test expectations on Spyable objects.",
    "description": "Spry+Nimble allows developers, used to working with Quick/Nimble, be able to test whether or not functions were called on objects in a helpful Nimble matcher. The haveReceived matcher contains rich failure messages when tests fail.",
    "homepage": "https://github.com/Rivukis/Spry",
    "license": {
        "type": "MIT",
        "file": "LICENSE"
    },
    "authors": {
        "Brian Radebaugh": "[email protected]"
    },
    "source": {
        "git": "https://github.com/Rivukis/Spry.git",
        "tag": "2.2.4"
    },
    "platforms": {
        "ios": "9.0"
    },
    "source_files": "Example/SourceNimble/*",
    "frameworks": "XCTest",
    "dependencies": {
        "Nimble": [
            "> 7.0.0"
        ],
        "Spry": [
            "2.2.4"
        ]
    },
    "pushed_with_swift_version": "3.0"
}

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