added missing Append extensions

Raliway.Tests/Results/Combine.cs

@@ -0,0 +1,78 @@
+namespace Raliway.Tests.Results;
+
+public class Combine
+{
+    [Fact]
+    public void TwoResultCombination_WhenThereIsAnError()
+    {
+        // Given
+        var result1 = Result.Success(1);
+        var result2 = Result.Failure(Error.New("some error"));
+        // When
+        var result = Result.Combine(result1, result2);
+        // Then
+        Assert.True(result.IsFailure);
+        Assert.Equal(result2.Error, result.Error);
+    }
+    [Fact]
+    public void TwoResultCombination_WhenThereAreTwoErrors()
+    {
+        // Given
+        var result1 = Result.Failure<byte>(Error.New("1"));
+        var result2 = Result.Failure(Error.New("2"));
+        // When
+        var result = Result.Combine(result1, result2);
+        // Then
+        Assert.True(result.IsFailure);
+        Assert.Equal(result1.Error + result2.Error, result.Error);
+    }
+    [Fact]
+    public void TwoResultCombination_WhenThereIsNoError()
+    {
+        // Given
+        var result1 = Result.Success(1);
+        var result2 = Result.Success(3.14);
+        // When
+        var result = Result.Combine(result1, result2);
+        // Then
+        Assert.True(result.IsSuccess);
+    }
+    [Fact]
+    public void ThreeResultCombination_WhenThereIsAnError()
+    {
+        // Given
+        var result1 = Result.Success(1);
+        var result2 = Result.Success(3.14);
+        var result3 = Result.Failure(Error.New("some error"));
+        // When
+        Result<(int, double)> result = Result.Combine(result1, result2, result3);
+        // Then
+        Assert.True(result.IsFailure);
+        Assert.Equal(result3.Error, result.Error);
+    }
+    [Fact]
+    public void ThreeResultCombination_WhenThereAreTwoErrors()
+    {
+        // Given
+        var result1 = Result.Failure<int?>(Error.New("1"));
+        var result2 = Result.Success(3.14);
+        var result3 = Result.Failure(Error.New("3"));
+        // When
+        Result<(int?, double)> result = Result.Combine(result1, result2, result3);
+        // Then
+        Assert.True(result.IsFailure);
+        Assert.Equal(result1.Error + result3.Error, result.Error);
+    }
+    [Fact]
+    public void ThreeResultCombination_WhenThereIsNoError()
+    {
+        // Given
+        var result1 = Result.Success(1);
+        var result2 = Result.Success(3.14);
+        var result3 = Result.Success();
+        // When
+        var result = Result.Combine(result1, result2, result3);
+        // Then
+        Assert.True(result.IsSuccess);
+    }
+}