From 1e0ad9a6909d55399c880085e49eab08f4251393 Mon Sep 17 00:00:00 2001
From: Laurence King <53393540+LaurenceJKing@users.noreply.github.com>
Date: Tue, 6 Apr 2021 22:19:58 +0100
Subject: [PATCH] Allow xUnit Properties attribute to be used at assembly level
 (#559)

---
 docs/RunningTests.fsx                         | 24 +++++--
 src/FsCheck.Xunit/PropertyAttribute.fs        | 29 ++++----
 tests/FsCheck.Test/FsCheck.Test.fsproj        |  1 +
 .../Fscheck.XUnit/PropertyAttributeTests.fs   | 69 +++++++++++++++++++
 4 files changed, 104 insertions(+), 19 deletions(-)
 create mode 100644 tests/FsCheck.Test/Fscheck.XUnit/PropertyAttributeTests.fs

diff --git a/docs/RunningTests.fsx b/docs/RunningTests.fsx
index f8c945af..58df8617 100644
--- a/docs/RunningTests.fsx
+++ b/docs/RunningTests.fsx
@@ -148,23 +148,39 @@ instance just for that test method. You can also use the `PropertiesAttribute` (
 type Positive =
     static member Double() =
         Arb.Default.Float()
-        |> Arb.mapFilter abs (fun t -> t >= 0.0)
+        |> Arb.mapFilter abs (fun t -> t > 0.0)
 
 type Negative =
     static member Double() =
         Arb.Default.Float()
-        |> Arb.mapFilter (abs >> ((-) 0.0)) (fun t -> t <= 0.0)
+        |> Arb.mapFilter (abs >> ((-) 0.0)) (fun t -> t < 0.0)
+
+type Zero =
+    static member Double() =
+        0.0
+        |> Gen.constant
+        |> Arb.fromGen
+
+[<assembly: Properties( Arbitrary = [| typeof<Zero> |])>] do()
+module ModuleWithoutProperties =
+    [<Property>]
+    let ``should use Arb instances from assembly``(underTest:float) =
+        underTest = 0.0
+
+    [<Property( Arbitrary=[| typeof<Positive> |] )>]
+    let ``should use Arb instance on method``(underTest:float) =
+        underTest > 0.0
 
 [<Properties( Arbitrary=[| typeof<Negative> |] )>]
 module ModuleWithProperties =
 
     [<Property>]
     let ``should use Arb instances from enclosing module``(underTest:float) =
-        underTest <= 0.0
+        underTest < 0.0
 
     [<Property( Arbitrary=[| typeof<Positive> |] )>]
     let ``should use Arb instance on method``(underTest:float) =
-        underTest >= 0.0
+        underTest > 0.0
 
 (**
 Using `PropertiesAttribute` and `PropertyAttribute` you can set any configuration. For example in following module:
diff --git a/src/FsCheck.Xunit/PropertyAttribute.fs b/src/FsCheck.Xunit/PropertyAttribute.fs
index 139d1378..68e1788e 100644
--- a/src/FsCheck.Xunit/PropertyAttribute.fs
+++ b/src/FsCheck.Xunit/PropertyAttribute.fs
@@ -148,33 +148,32 @@ type public PropertyAttribute() =
     member internal __.Config = config
 
 ///Set common configuration for all properties within this class or module
-[<AttributeUsage(AttributeTargets.Class, AllowMultiple = false)>]
+[<AttributeUsage(AttributeTargets.Class ||| AttributeTargets.Assembly, AllowMultiple = false)>]
 type public PropertiesAttribute() = inherit PropertyAttribute()
 
 /// The xUnit2 test runner for the PropertyAttribute that executes the test via FsCheck
-type PropertyTestCase(diagnosticMessageSink:IMessageSink, defaultMethodDisplay:TestMethodDisplay, testMethod:ITestMethod, ?testMethodArguments:obj []) =
+type PropertyTestCase(diagnosticMessageSink:IMessageSink, defaultMethodDisplay:TestMethodDisplay, testMethod:ITestMethod, ?testMethodArguments:obj []) =    
     inherit XunitTestCase(diagnosticMessageSink, defaultMethodDisplay, testMethod, (match testMethodArguments with | None -> null | Some v -> v))
 
+    let combineAttributes (attributes: (IAttributeInfo option) list) =
+        attributes
+        |> List.choose id
+        |> List.map(fun attr -> attr.GetNamedArgument<PropertyConfig> "Config")
+        |> List.reduce(fun higherLevelAttribute lowerLevelAttribute -> 
+            PropertyConfig.combine lowerLevelAttribute higherLevelAttribute)
+
     new() = new PropertyTestCase(null, TestMethodDisplay.ClassAndMethod, null)
 
     member this.Init(output:TestOutputHelper) =
-        let factAttribute = this.TestMethod.Method.GetCustomAttributes(typeof<PropertyAttribute>) |> Seq.head
         let arbitrariesOnClass =
             this.TestMethod.TestClass.Class.GetCustomAttributes(Type.GetType("FsCheck.Xunit.ArbitraryAttribute"))
                 |> Seq.collect (fun attr -> attr.GetNamedArgument "Arbitrary")
                 |> Seq.toArray
-        let generalAttribute = 
-            this.TestMethod.TestClass.Class.GetCustomAttributes(typeof<PropertiesAttribute>) 
-                |> Seq.tryFind (fun _ -> true)
-
-        let config =
-            match generalAttribute with
-            | Some generalAttribute ->
-                PropertyConfig.combine
-                    (factAttribute.GetNamedArgument "Config")
-                    (generalAttribute.GetNamedArgument "Config")
-            | None ->
-                factAttribute.GetNamedArgument "Config"
+
+        let config = combineAttributes [
+            this.TestMethod.TestClass.Class.Assembly.GetCustomAttributes(typeof<PropertiesAttribute>) |> Seq.tryHead
+            this.TestMethod.TestClass.Class.GetCustomAttributes(typeof<PropertiesAttribute>) |> Seq.tryHead
+            this.TestMethod.Method.GetCustomAttributes(typeof<PropertyAttribute>) |> Seq.head |> Some]
         
         { config with Arbitrary = Array.append config.Arbitrary arbitrariesOnClass }
         |> PropertyConfig.toConfig output 
diff --git a/tests/FsCheck.Test/FsCheck.Test.fsproj b/tests/FsCheck.Test/FsCheck.Test.fsproj
index 50949ddd..1d3bb989 100644
--- a/tests/FsCheck.Test/FsCheck.Test.fsproj
+++ b/tests/FsCheck.Test/FsCheck.Test.fsproj
@@ -9,6 +9,7 @@
     <DefineConstants>DEBUG</DefineConstants>
   </PropertyGroup>
   <ItemGroup>
+    <Compile Include="Fscheck.XUnit\PropertyAttributeTests.fs" />
     <Compile Include="Helpers.fs" />
     <Compile Include="Random.fs" />
     <Compile Include="TypeClass.fs" />
diff --git a/tests/FsCheck.Test/Fscheck.XUnit/PropertyAttributeTests.fs b/tests/FsCheck.Test/Fscheck.XUnit/PropertyAttributeTests.fs
new file mode 100644
index 00000000..119388e8
--- /dev/null
+++ b/tests/FsCheck.Test/Fscheck.XUnit/PropertyAttributeTests.fs
@@ -0,0 +1,69 @@
+namespace Fscheck.Test.FsCheck.XUnit.PropertyAttribute
+open FsCheck.Xunit
+open FsCheck
+
+type AttributeLevel =
+| Assembly
+| ClassOrModule
+| NestedClassOrModule
+| MethodOrProperty
+
+type AttributeLevel_Assembly() =
+    static member Generator = 
+        Assembly
+        |> Gen.constant
+        |> Arb.fromGen
+
+type AttributeLevel_ClassOrModule() =
+    static member Generator = 
+        ClassOrModule
+        |> Gen.constant
+        |> Arb.fromGen
+
+type AttributeLevel_MethodOrProperty() =
+    static member Generator =
+        MethodOrProperty
+        |> Gen.constant
+        |> Arb.fromGen
+
+type AttributeLevel_NestedClassOrModule() =
+    static member Generator =
+        NestedClassOrModule
+        |> Gen.constant
+        |> Arb.fromGen
+
+[<assembly: Properties(Arbitrary = [| typeof<AttributeLevel_Assembly> |])>]
+do()
+
+module ``when module does not have properties attribute``=
+    [<Property>]
+    let ``then the assembly attribute should be used`` = function
+    | Assembly -> true
+    | _ -> false
+
+    [<Property(Arbitrary = [| typeof<AttributeLevel_MethodOrProperty>|])>]
+    let ``then the property attribute takes precient`` = function
+    | MethodOrProperty -> true
+    | _ -> false
+
+[<Properties(Arbitrary = [|typeof<AttributeLevel_ClassOrModule>|])>]
+module ``when module has properties attribute`` =
+
+    [<Property>]
+    let ``then the module's property takes precident`` = function
+    | ClassOrModule -> true
+    | _ -> false
+
+    [<Property(Arbitrary = [| typeof<AttributeLevel_MethodOrProperty>|])>]
+    let ``then the property attribute takes precient`` = function
+    | MethodOrProperty -> true
+    | _ -> false
+
+    [<Properties(Arbitrary = [|typeof<AttributeLevel_NestedClassOrModule>|])>]
+    module ``and there is and nested module`` =
+        [<Property>]
+        let ``then the nested module's property takes precident`` = function
+        | NestedClassOrModule -> true
+        | _ -> false
+
+