Added test project & github action to run tests

.github/workflows/test.yml

@@ -0,0 +1,57 @@
+# The name of the workflow.
+# This is the name that's displayed for status
+# badges (commonly embedded in README.md files).
+name: tests
+
+# Trigger this workflow on a push, or pull request to
+# the production branch, when either C# or project files changed
+on:
+  push:
+  pull_request:
+    branches: [ main ]
+    paths-ignore:
+    - 'README.md'
+
+# Create an environment variable named DOTNET_VERSION
+# and set it as "6.0.x"
+env:
+  DOTNET_VERSION: '6.0.x' # The .NET SDK version to use
+
+# Defines a single job named "build-and-test"
+jobs:
+  build-and-test:
+
+    # When the workflow runs, this is the name that is logged
+    # This job will run three times, once for each "os" defined
+    name: build-and-test-${{matrix.os}}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+
+    # Each job run contains these five steps
+    steps:
+    # 1) Check out the source code so that the workflow can access it.
+    - uses: actions/checkout@v2
+
+    # 2) Set up the .NET CLI environment for the workflow to use.
+    #    The .NET version is specified by the environment variable.
+    - name: Setup .NET
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: ${{ env.DOTNET_VERSION }}
+
+    # 3) Restore the dependencies and tools of a project or solution.
+    - name: Install dependencies
+      working-directory: ./Source
+      run: dotnet restore
+
+    # 4) Build a project or solution and all of its dependencies.
+    - name: Build
+      working-directory: ./Source
+      run: dotnet build --configuration Debug --no-restore
+
+    # 5) Test a project or solution.
+    - name: Test
+      working-directory: ./Source
+      run: dotnet test --no-restore --verbosity normal

Source/Morris.Reducible.Tests/Morris.Reducible.Tests.csproj

@@ -0,0 +1,28 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <Nullable>enable</Nullable>
+
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
+    <PackageReference Include="xunit" Version="2.4.1" />
+    <PackageReference Include="xunit.extensibility.core" Version="2.4.1" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="coverlet.collector" Version="3.1.0">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Morris.Reducible\Morris.Reducible.csproj" />
+  </ItemGroup>
+
+</Project>

Source/Morris.Reducible.Tests/ReducerTests.cs

@@ -0,0 +1,67 @@
+using Xunit;
+
+namespace Morris.Reducible.Tests
+{
+	public class ReducerTests
+    {
+	    private record CounterState(int Counter);
+	    private record IncrementCounter(int Amount);
+
+
+		[Fact]
+	    public void ReducerUpdatesStateWhenInvoked()
+	    {
+			//Given
+			var initialState = new CounterState(0);
+			var action = new IncrementCounter(1);
+			var counterIncrementCounterReducer = Reducer
+			 .Given<CounterState, IncrementCounter>()
+			 .Then((state, delta) => (true, state with { Counter = state.Counter + delta.Amount}));
+
+			//When
+			(bool changed, var counterState) = counterIncrementCounterReducer.Invoke(initialState, action);
+
+			//Then
+			Assert.True(changed);
+			Assert.Equal(new CounterState(1), counterState);
+	    }	
+
+	    [Fact]
+	    public void ReducerUpdatesStateWhenInvokedWithPassingCondition()
+	    {
+			//Given
+			var initialState = new CounterState(0);
+			var action = new IncrementCounter(1);
+			var counterIncrementCounterReducer = Reducer
+				.Given<CounterState, IncrementCounter>()
+				.When((state, delta) => state.Counter < 2)
+				.Then((state, delta) => state with { Counter = state.Counter + delta.Amount });
+
+			//When
+			(bool changed, var counterState) = counterIncrementCounterReducer.Invoke(initialState, action);
+
+			//Then
+			Assert.True(changed);
+			Assert.Equal(new CounterState(1), counterState);
+	    }
+
+	    [Fact]
+	    public void ReducerDoesNotUpdateStateWhenInvokedWithFailingCondition()
+	    {
+		    //Given
+		    var initialState = new CounterState(0);
+		    var action = new IncrementCounter(1);
+		    var counterIncrementCounterReducer = Reducer
+			    .Given<CounterState, IncrementCounter>()
+			    .When((state, delta) => state.Counter > 2)
+			    .Then((state, delta) => state with { Counter = state.Counter + delta.Amount });
+
+		    //When
+		    (bool changed, var counterState) = counterIncrementCounterReducer.Invoke(initialState, action);
+
+		    //Then
+		    Assert.False(changed);
+		    Assert.Equal(new CounterState(0), counterState);
+	    }
+	}
+}

Source/Morris.Reducible.sln

@@ -44,6 +44,8 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Docs", "Docs", "{047A19CC-B
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PolyMorphicReducers", "Tutorials\06-PolymorphicReducers\PolyMorphicReducers.csproj", "{7EFBF5C3-8A70-4E04-B5C1-75C3EA09A76D}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Morris.Reducible.Tests", "Morris.Reducible.Tests\Morris.Reducible.Tests.csproj", "{5522941C-7016-4634-8477-41B2274D1DBB}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -78,6 +80,10 @@ Global
 		{7EFBF5C3-8A70-4E04-B5C1-75C3EA09A76D}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{7EFBF5C3-8A70-4E04-B5C1-75C3EA09A76D}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{7EFBF5C3-8A70-4E04-B5C1-75C3EA09A76D}.Release|Any CPU.Build.0 = Release|Any CPU
+		{5522941C-7016-4634-8477-41B2274D1DBB}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{5522941C-7016-4634-8477-41B2274D1DBB}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{5522941C-7016-4634-8477-41B2274D1DBB}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{5522941C-7016-4634-8477-41B2274D1DBB}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

Source/Morris.Reducible/Reducer.Builder.cs

@@ -7,7 +7,7 @@ namespace Morris.Reducible;
 
 public static partial class Reducer
 {
-	public static Builder<TState> New<TState>() => new Builder<TState>();
+	public static Builder<TState> New<TState>() => new();
 
 	public class Builder<TState>
 	{

Source/Morris.Reducible/Reducer.ConditionBuilder.cs

@@ -9,7 +9,7 @@ public class ConditionBuilder<TState, TDelta>
 	{
 		internal ConditionBuilder() { }
 
-		public ResultMapper<TState, TDelta> When(Func<TState, TDelta, bool> condition) => new ResultMapper<TState, TDelta>(condition);
+		public ResultMapper<TState, TDelta> When(Func<TState, TDelta, bool> condition) => new(condition);
 
 		public Func<TState, TDelta, Result<TState>> Then(Func<TState, TDelta, Result<TState>> reducer)
 		{
@@ -20,15 +20,11 @@ public Func<TState, TDelta, Result<TState>> Then(Func<TState, TDelta, Result<TSt
 		}
 
 		public ObjectResultMapper<TState, TSubState, TDelta> WhenReducedBy<TSubState>(
-			Func<TState, TSubState> subStateSelector,
-			Func<TSubState, TDelta, Result<TSubState>> reducer)
-		=>
-			new ObjectResultMapper<TState, TSubState, TDelta>(subStateSelector, reducer);
+			Func<TState, TSubState> subStateSelector, Func<TSubState, TDelta, Result<TSubState>> reducer) =>
+			new(subStateSelector, reducer);
 
 		public ImmutableArrayResultMapper<TState, TElement, TDelta> WhenReducedBy<TElement>(
-			Func<TState, ImmutableArray<TElement>> subStateSelector,
-			Func<TElement, TDelta, Result<TElement>> reducer)
-			=>
-				new ImmutableArrayResultMapper<TState, TElement, TDelta>(subStateSelector, reducer);
+			Func<TState, ImmutableArray<TElement>> subStateSelector, Func<TElement, TDelta, Result<TElement>> reducer) =>
+			new(subStateSelector, reducer);
 	}
 }

Source/Morris.Reducible/Reducer.Result.cs

@@ -5,6 +5,6 @@ public static partial class Reducer
 	public record struct Result<TState>(bool Changed, TState State)
 	{
 		public static implicit operator (bool changed, TState state)(Result<TState> result) => (result.Changed, result.State);
-		public static implicit operator Result<TState>((bool changed, TState value) value) => new Result<TState>(value.changed, value.value);
+		public static implicit operator Result<TState>((bool changed, TState value) value) => new(value.changed, value.value);
 	}
 }

Source/Morris.Reducible/Reducer.cs

@@ -6,9 +6,9 @@ namespace Morris.Reducible;
 
 public static partial class Reducer
 {
-	public static ConditionBuilder<TState, TDelta> Given<TState, TDelta>() => new ConditionBuilder<TState, TDelta>();
+	public static ConditionBuilder<TState, TDelta> Given<TState, TDelta>() => new();
 
-	public static Builder<TState> CreateBuilder<TState>() => new Builder<TState>();
+	public static Builder<TState> CreateBuilder<TState>() => new();
 
 	public static Func<TState, TDelta, Result<TState>> Combine<TState, TDelta>(params Func<TState, TDelta, Result<TState>>[] reducers)
 	{
@@ -23,10 +23,9 @@ public static Func<TState, TDelta, Result<TState>> Combine<TState, TDelta>(param
 		return (state, delta) =>
 		{
 			bool anyChanged = false;
-			for (int o = 0; o < allReducers.Length; o++)
+			foreach (var reducer in allReducers)
 			{
-				(bool changed, state) = allReducers[o](state, delta);
-				anyChanged |= changed;
+				anyChanged |= reducer(state, delta).Changed;
 			}
 			return (anyChanged, state);
 		};