Unquote, App.config, and You

"What curious eye doth quote deformities?"
-- Shakespeare, Romeo and Juliet
Act I, Scene IV, Line 31

I've started using Unquote for my assertions with F# xUnit tests.  I find that its step-by-step failure messages really help in figuring out what is going on.

One thing that really throw me when I first used it was the System.MissingMethodException exception that Unquote was throwing at runtime.  Luckily I was able to find this StackOverflow answer.  It seems that you need to do a binding redirect for FSharp.Core, so you'll need to set up an App.config file in your test project like this example of the Coin Changer kata (using MapFold).

	<?xml version="1.0" encoding="utf-8" ?>
	<configuration>
	<runtime>
	<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
	<dependentAssembly>
	<assemblyIdentity name="FSharp.Core"
	publicKeyToken="b03f5f7f11d50a3a"
	culture="neutral"/>
	<bindingRedirect oldVersion="4.3.1.0"
	newVersion="4.4.0.0"/>
	</dependentAssembly>
	</assemblyBinding>
	</runtime>
	</configuration>

view raw App.config hosted with ❤ by GitHub

	namespace CoinChanger
	module Changer =
	let change coins amount =
	coins
	|> List.mapFold
	(fun amount coin -> List.replicate <| amount / coin <| coin, amount % coin)
	amount
	|> fst
	|> List.reduce (@)

view raw Changer.fs hosted with ❤ by GitHub

	namespace CoinChangerTests
	module ChangerTests =
	open Xunit
	open Swensen.Unquote
	open CoinChanger.Changer
	[<Theory>]
	[<InlineData(0)>]
	[<InlineData(1)>]
	[<InlineData(99)>]
	let ``given pennies it must return coins equal to amount given`` amount =
	let pennies = [1]
	test <@
	change pennies amount |> List.length = amount
	@>
	[<Theory>]
	[<InlineData(0, 10)>]
	[<InlineData(1, 5)>]
	[<InlineData(42, 25)>]
	[<InlineData(99, 20)>]
	let ``given number of coins and value it must return number of coins`` number value =
	let coins = [value]
	test <@
	change coins <| number * value |> List.length = number
	@>
	[<Theory>]
	[<InlineData(1)>]
	[<InlineData(10)>]
	[<InlineData(99)>]
	let ``given coin values it must return coins of that value`` value =
	let coins = [value]
	let amount = 99
	test <@
	let unique = change coins amount |> List.distinct
	unique |> List.length = 1
	&&
	unique |> List.head = value
	@>
	[<Fact>]
	let ``given full register and 1 of each coin it must return 1 of each coin`` () =
	let register = [25; 10; 5; 1]
	let amount = List.sum register
	test <@
	change register amount |> List.distinct = register
	@>
	[<Theory>]
	[<InlineData(0)>]
	[<InlineData(1)>]
	[<InlineData(42)>]
	[<InlineData(99)>]
	let ``given full register it must return coins summing to amount`` amount =
	let register = [25; 10; 5; 1]
	test <@
	change register amount |> List.sum = amount
	@>

view raw ChangerTests.fs hosted with ❤ by GitHub

Happy coding.