AdventOfCode 2023 Day09

AdventOfCode2023.Tests/Day09_Tests.cs

@@ -0,0 +1,78 @@
+namespace AdventOfCode2023.Tests;
+
+public class Day09_Tests
+{
+    private readonly string[] _example = {
+        "0 3 6 9 12 15",
+        "1 3 6 10 15 21",
+        "10 13 16 21 30 45",
+    };
+
+    [Fact]
+    public void ResolvePart1__Example()
+    {
+        Day09 day = new();
+        
+        string result = day.ResolvePart1(_example);
+
+        Assert.Equal("114", result);
+    }
+
+    [Fact]
+    public void ResolvePart2__Example()
+    {
+        Day09 day = new();
+        
+        string result = day.ResolvePart2(_example);
+
+        Assert.Equal("2", result);
+    }
+
+    [Fact]
+    public void Extrapolator_Extrapolate__Example1()
+    {
+        Day09.Extrapolator extrapolator = new("0 3 6 9 12 15");
+        long result = extrapolator.Extrapolate();
+        Assert.Equal(18, result);
+    }
+    
+    [Fact]
+    public void Extrapolator_Extrapolate__Example2()
+    {
+        Day09.Extrapolator extrapolator = new("1 3 6 10 15 21");
+        long result = extrapolator.Extrapolate();
+        Assert.Equal(28, result);
+    }
+    
+    [Fact]
+    public void Extrapolator_Extrapolate__Example3()
+    {
+        Day09.Extrapolator extrapolator = new("10 13 16 21 30 45");
+        long result = extrapolator.Extrapolate();
+        Assert.Equal(68, result);
+    }
+
+    [Fact]
+    public void Extrapolator_ExtrapolatePast__Example1()
+    {
+        Day09.Extrapolator extrapolator = new("0 3 6 9 12 15");
+        long result = extrapolator.ExtrapolatePast();
+        Assert.Equal(-3, result);
+    }
+    
+    [Fact]
+    public void Extrapolator_ExtrapolatePast__Example2()
+    {
+        Day09.Extrapolator extrapolator = new("1 3 6 10 15 21");
+        long result = extrapolator.ExtrapolatePast();
+        Assert.Equal(0, result);
+    }
+    
+    [Fact]
+    public void Extrapolator_ExtrapolatePast__Example3()
+    {
+        Day09.Extrapolator extrapolator = new("10 13 16 21 30 45");
+        long result = extrapolator.ExtrapolatePast();
+        Assert.Equal(5, result);
+    }
+}