create a public function for creating a solid brush using an RGBASpec.

Add property tests for the above function.

DeathSocket/ColourServices.fs

@@ -3,7 +3,6 @@
     open System.Drawing
     open DeathSocket.Domain
 
-    // not tested
     let makeBrushFromRGBASpec (spec: RGBASpec) =
         let a = int spec.alpha
         let r = int spec.red
@@ -12,7 +11,6 @@
         let colour = Color.FromArgb (a, r, g, b)
         new SolidBrush (colour)
 
-    // not tested
     let makeBrushFromRGBA r g b a =
         let colour = Color.FromArgb (a, r, g, b)
         new SolidBrush (colour)

DeathSocket/GridPainter.fs

@@ -55,9 +55,10 @@ namespace DeathSocket
 
         // let applyCMYKGridAsync -- to be added at a later date.
 
-        // not tested.
         let makeSolidBrushFromRGBA r g b a = makeBrushFromRGBA r g b a
 
+        let makeSolidBrushFromRGBASpec spec = makeBrushFromRGBASpec spec
+
         // not tested or completed.
         let makeSolidBrushFromCMYK c m y k =
             ""

TestCentre/LibraryTests.fs

@@ -20,6 +20,7 @@
         open System.Drawing
         open System.Reflection
         open System.IO
+        open DeathSocket.Domain
 
         let rand = Random ()
 
@@ -68,6 +69,18 @@
                 files
                 |> Array.iter (fun f -> File.Delete(f))
 
+        let makeTestRGBASpec r g b a =
+            { originalPath = "test path"
+              savePath = "test path"
+              alpha = float a
+              red = float r
+              green = float g
+              blue = float b
+              penWidth = float32 10
+              rows = newNum ()
+              columns = newNum () }
+
+
     module PropertyTests =
 
         open FsCheck.Xunit
@@ -108,6 +121,17 @@
             let brush = makeSolidBrushFromRGBA r g b a
             brush.Color = referenceColour
 
+        [<Property>]
+        let ``SolidBrush colour matches the RGBASpec`` () =
+            let a = newRGBANum ()
+            let r = newRGBANum ()
+            let g = newRGBANum ()
+            let b = newRGBANum ()
+            let referenceColour = Color.FromArgb (a, r, g, b)
+            let referenceSpec = makeTestRGBASpec r g b a
+            let brush = makeSolidBrushFromRGBASpec referenceSpec
+            brush.Color = referenceColour
+
 
         [<Property>]
         let ``Can return a collection of points which represent a grids horizontal lines`` () =