From f54f8f397a36630e85d0fc8b00ad210390e1180d Mon Sep 17 00:00:00 2001
From: MarcUs7i <96580944+MarcUs7i@users.noreply.github.com>
Date: Wed, 27 Nov 2024 17:56:36 +0100
Subject: [PATCH] Added Remove Tests and Remove Methods

---
 FlexArray.Test/FlexArrayStringTests.cs | 162 +++++++++++++++++++++++++
 FlexArray/FlexArrayString.cs           |  47 +++++++
 2 files changed, 209 insertions(+)

diff --git a/FlexArray.Test/FlexArrayStringTests.cs b/FlexArray.Test/FlexArrayStringTests.cs
index 9b769be..db02392 100644
--- a/FlexArray.Test/FlexArrayStringTests.cs
+++ b/FlexArray.Test/FlexArrayStringTests.cs
@@ -180,4 +180,166 @@ public class FlexArrayStringTests
             array[i].Should().Be(i.ToString());
         }
     }
+    
+    // Remove tests
+    [Fact]
+    public void Remove_ByIndex_Simple()
+    {
+        var array = new FlexArrayString();
+        array.Add("Hello");
+
+        array.Count.Should().Be(1);
+        array.RemoveAt(0).Should().BeTrue("index exists");
+        array.Count.Should().Be(0, "count has to be reduced");
+    }
+
+    [Fact]
+    public void Remove_ByIndex_Shifting()
+    {
+        var array = new FlexArrayString();
+        array.Add("Goodbye");
+        array.Add("World");
+        array.Add("!");
+
+        array.Count.Should().Be(3);
+        array.RemoveAt(1).Should().BeTrue();
+        array.Count.Should().Be(2);
+        array[1].Should().Be("!", "items to the right have to be shifted left after removal");
+        array.RemoveAt(2)
+             .Should().BeFalse("not a valid index any longer, despite a value still being there");
+    }
+
+    [Fact]
+    public void Remove_ByIndex_FromEnd()
+    {
+        var array = new FlexArrayString();
+        array.Add("Hello");
+        array.Add("World");
+        array.Add("!");
+
+        array.Count.Should().Be(3);
+        array.RemoveAt(2).Should().BeTrue();
+        array.Count.Should().Be(2);
+        array[1].Should().Be("World");
+    }
+
+    [Fact]
+    public void Remove_ByIndex_Invalid()
+    {
+        var array = new FlexArrayString();
+        array.Add("This is a test!");
+
+        array.RemoveAt(1)
+             .Should().BeFalse("the array is big enough for this index, but no value has been set there");
+        array.Count.Should().Be(1, "unchanged");
+
+        array.RemoveAt(-1)
+             .Should().BeFalse("negative index doesn't make any sense");
+    }
+    
+    [Fact]
+    public void Remove_Single_OneOccurrence()
+    {
+        var array = new FlexArrayString();
+        array.Add("Hello");
+        array.Add("corrupted");
+        array.Add("World!");
+
+        array.Remove("corrupted", true)
+            .Should().BeTrue("element was found");
+        array.Count.Should().Be(2, "element was removed");
+    }
+
+    [Fact]
+    public void Remove_Single_OnlyOccurrence()
+    {
+        var array = new FlexArrayString();
+        array.Add("Hello");
+
+        array.Remove("Hello", true)
+            .Should().BeTrue("element was found");
+        array.Count.Should().Be(0, "element was removed");
+    }
+
+    [Fact] public void Remove_Single_MultipleOccurrence()
+    {
+        var array = new FlexArrayString();
+        array.Add("Ever");
+        array.Add("used");
+        array.Add("kubernetes?");
+        
+        array.Remove("kubernetes?", true)
+            .Should().BeTrue("element was found");
+        array.Count.Should().Be(2, "only one element was removed");
+    }
+
+    [Fact]
+    public void Remove_Single_NotFound()
+    {
+        var array = new FlexArrayString();
+        array.Add("1");
+        array.Add("2");
+        array.Add("3");
+
+        array.Remove("4", true)
+            .Should().BeFalse("element was not found");
+        array.Count.Should().Be(3, "unchanged");
+    }
+
+    [Fact]
+    public void Remove_Multiple_OneOccurrence()
+    {
+        var array = new FlexArrayString();
+        array.Add("1");
+        array.Add("2");
+        array.Add("3");
+
+        array.Remove("2", false)
+            .Should().BeTrue("element was found");
+        array.Count.Should().Be(2, "only one element was removed");
+    }
+
+    [Fact]
+    public void Remove_Multiple_MultipleOccurrence()
+    {
+        var array = new FlexArrayString();
+        array.Add("1");
+        array.Add("2");
+        array.Add("2");
+        array.Add("3");
+        array.Add("2");
+        array.Add("4");
+        array.Add("2");
+
+        array.Remove("2", false)
+            .Should().BeTrue("elements were found");
+        array.Count.Should().Be(3, "four elements were removed");
+    }
+
+    [Fact]
+    public void Remove_Multiple_OnlyOccurrence()
+    {
+        var array = new FlexArrayString();
+        array.Add("1");
+        array.Add("1");
+        array.Add("1");
+
+
+        array.Remove("1", false)
+            .Should().BeTrue("elements were found");
+        array.Count.Should().Be(0, "all elements were removed");
+    }
+
+    [Fact]
+    public void Remove_Multiple_NoOccurrence()
+    {
+        var array = new FlexArrayString();
+        array.Add("1");
+        array.Add("2");
+        array.Add("3");
+
+        array.Remove("4", false)
+            .Should().BeFalse("element was not found");
+        array.Count.Should().Be(3, "unchanged");
+    }
 }
diff --git a/FlexArray/FlexArrayString.cs b/FlexArray/FlexArrayString.cs
index 9e10465..a5fd023 100644
--- a/FlexArray/FlexArrayString.cs
+++ b/FlexArray/FlexArrayString.cs
@@ -55,6 +55,53 @@ public class FlexArrayString
 
         return false;
     }
+    
+    public bool Remove(string value, bool firstOnly)
+    {
+        var removedAny = false;
+        for (var i = 0; i < Count; i++)
+        {
+            if (value != _data[i])
+            {
+                continue;
+            }
+
+            RemoveAt(i--);
+            removedAny = true;
+            if (firstOnly)
+            {
+                break;
+            }
+        }
+
+        return removedAny;
+    }
+
+    public bool RemoveAt(int index)
+    {
+        if (index < 0 || index >= Count)
+        {
+            return false;
+        }
+
+        if (index != Count - 1)
+        {
+            ShiftLeft(index);
+            
+        }
+
+        Count--;
+
+        return true;
+    }
+
+    private void ShiftLeft(int fromIndex)
+    {
+        for (var i = fromIndex; i < Count; i++)
+        {
+            _data[i] = _data[i + 1];
+        }
+    }
 
     private void Grow()
     {