From ea83219937cd893e19a109e09bd07a59a3590c10 Mon Sep 17 00:00:00 2001
From: Radu Popovici <oncicaradupopovici@gmail.com>
Date: Wed, 18 Mar 2020 23:46:29 +0200
Subject: [PATCH] Feature/evented fns (#70)

* Evented addEvent

* exec mapE listen

Co-authored-by: Radu Popovici <rpopovici@totalsoft.ro>
---
 src/Core/NBB.Core.Evented.FSharp/Evented.fs   | 10 +++++-
 .../NBB.Core.Evented.FSharp.Tests.fsproj      |  1 +
 .../NBB.Core.Evented.FSharp.Tests/Sample.fs   |  3 +-
 .../NBB.Core.Evented.FSharp.Tests/Sample2.fs  | 31 +++++++++++++++++++
 4 files changed, 42 insertions(+), 3 deletions(-)
 create mode 100644 test/UnitTests/Core/NBB.Core.Evented.FSharp.Tests/Sample2.fs

diff --git a/src/Core/NBB.Core.Evented.FSharp/Evented.fs b/src/Core/NBB.Core.Evented.FSharp/Evented.fs
index fe473530..d688f883 100644
--- a/src/Core/NBB.Core.Evented.FSharp/Evented.fs
+++ b/src/Core/NBB.Core.Evented.FSharp/Evented.fs
@@ -2,6 +2,7 @@
 
 type Evented<'a, 'e> = Evented of payload:'a * events:'e list
 
+[<RequireQualifiedAccess>]
 module Evented = 
     let map func (Evented(value, events)) = Evented(func value, events)
 
@@ -17,6 +18,10 @@ module Evented =
 
     let lift2 f = map f >> apply
 
+    let run (Evented(value, events): Evented<'a, 'e>) = (value, events)
+    let exec (Evented(_value, events): Evented<'a, 'e>) = events
+    let mapE (func:'e->'f) (Evented(value, events): Evented<'a,'e>) = Evented(value, events |> List.map func)
+
 type Evented<'a, 'e> with
     static member Map (x, f) = Evented.map  f x
     static member Return (x) = Evented.return' x
@@ -32,7 +37,7 @@ module EventedBuilder =
         member _.Zero() = Evented.return' ()
 
 [<AutoOpen>]
-module Events =
+module EventedExtensions =
     let evented = new EventedBuilder.EventedBuilder()
 
     let (<!>) = Evented.map
@@ -40,6 +45,9 @@ module Events =
     let (>>=) evented func = Evented.bind func evented
     let (>=>) = Evented.composeK
 
+    let addEvent (ev:'e) = Evented((),[ev])
+    let listen (Evented (value, events): Evented<'a,'e>) = Evented((value,events),events)
+
 [<RequireQualifiedAccess>]
 module List =
     let traverseEvented f list =
diff --git a/test/UnitTests/Core/NBB.Core.Evented.FSharp.Tests/NBB.Core.Evented.FSharp.Tests.fsproj b/test/UnitTests/Core/NBB.Core.Evented.FSharp.Tests/NBB.Core.Evented.FSharp.Tests.fsproj
index 1f4430c8..5fbdc40e 100644
--- a/test/UnitTests/Core/NBB.Core.Evented.FSharp.Tests/NBB.Core.Evented.FSharp.Tests.fsproj
+++ b/test/UnitTests/Core/NBB.Core.Evented.FSharp.Tests/NBB.Core.Evented.FSharp.Tests.fsproj
@@ -9,6 +9,7 @@
 
   <ItemGroup>
     <Compile Include="Sample.fs" />
+    <Compile Include="Sample2.fs" />
     <Compile Include="Tests.fs" />
     <Compile Include="Program.fs" />
   </ItemGroup>
diff --git a/test/UnitTests/Core/NBB.Core.Evented.FSharp.Tests/Sample.fs b/test/UnitTests/Core/NBB.Core.Evented.FSharp.Tests/Sample.fs
index 7539d135..bb6ff3c5 100644
--- a/test/UnitTests/Core/NBB.Core.Evented.FSharp.Tests/Sample.fs
+++ b/test/UnitTests/Core/NBB.Core.Evented.FSharp.Tests/Sample.fs
@@ -1,4 +1,4 @@
-module Sample
+namespace NBB.Core.Evented.FSharp.Tests
 
 open NBB.Core.Evented.FSharp
 open FSharpPlus
@@ -10,7 +10,6 @@ module Domain =
         | Updated
 
     let create x =  Evented(AggRoot x, [Added])
-
     let update (x:AggRoot) = Evented(x, [Updated])
     let increment (AggRoot x) = AggRoot (x + 1)
 
diff --git a/test/UnitTests/Core/NBB.Core.Evented.FSharp.Tests/Sample2.fs b/test/UnitTests/Core/NBB.Core.Evented.FSharp.Tests/Sample2.fs
new file mode 100644
index 00000000..f666f0b3
--- /dev/null
+++ b/test/UnitTests/Core/NBB.Core.Evented.FSharp.Tests/Sample2.fs
@@ -0,0 +1,31 @@
+namespace NBB.Core.Evented.FSharp.Tests
+
+open NBB.Core.Evented.FSharp
+
+module Sample2 =
+    type Payment = {
+        Id: int
+        Amount: decimal
+        Cancelled: bool
+    }
+
+    type DomainEvent = 
+        | Added of Id:int * Amount:decimal
+        | Cancelled of Id:int
+
+    let create (id,amount) = 
+        evented{
+            let payment = {Id=id; Amount=amount; Cancelled=false}
+            do! addEvent <| Added(id,amount)
+            return payment
+        }
+
+    let cancell payment = 
+        evented{
+            let payment' = {payment with Cancelled=true}
+            do! addEvent <| Cancelled payment.Id
+            return payment'
+        }
+
+    let createCancelled = create >=> cancell
+