ptran123 · March 15, 2013 18:22 · Mar 15, 2013
diff --git a/gistfile1.cs b/gistfile1.cs
@@ -0,0 +1,78 @@
+public class StringBuilder2Test
+  {
+		[Fact]
+		public void ToString_IsEmpty_ReturnEmptyString()
+		{
+			var sb = new StringBuilder2();
+			Assert.Equal("", sb.ToString());
+		}
+
+		[Fact]
+		public void ToString_HasAValue_RetunsTheValue()
+		{
+			var sb = new StringBuilder2();
+
+			sb.AppendText("hello");
+			Assert.Equal("hello", sb.ToString());
+		}
+
+		[Fact]
+		public void ToString_AppendMultiple_RetunsMultipleValuesAppended()
+		{
+			var sb = new StringBuilder2();
+
+			sb.AppendText("hello");
+			sb.AppendText(" world");
+
+			Assert.Equal("hello world", sb.ToString());
+		}
+
+		[Fact]
+		public void ToString_AppendParameterAtTall_ReturnCorrectValue()
+		{
+			var sb = new StringBuilder2();
+
+			sb.AppendText("hello world {0}", "Peter");
+
+			Assert.Equal("hello world Peter", sb.ToString());
+		}
+
+		[Fact]
+		public void ToString_AppendParameterAtHead_ReturnCorrectValue()
+		{
+			var sb = new StringBuilder2();
+
+			sb.AppendText("{0} hello world", "Peter");
+
+			Assert.Equal("Peter hello world", sb.ToString());
+		}
+
+		[Fact]
+		public void ToString_AppendParameterAtMiddle_ReturnCorrectValue()
+		{
+			var sb = new StringBuilder2();
+
+			sb.AppendText("hello {0} world", "Peter");
+
+			Assert.Equal("hello Peter world", sb.ToString());
+		}
+
+		[Fact]
+		public void ToString_AppendTwoParameterAtTail_ReturnCorrectValue()
+		{
+			var sb = new StringBuilder2();
+			sb.AppendText("hello world {0} {1}", "Peter", "Tran");
+
+			Assert.Equal("hello world Peter Tran", sb.ToString());
+		}
+
+		[Fact]
+		public void ToString_AppendThreeParameterAtTail_ReturnCorrectValue()
+		{
+			var sb = new StringBuilder2();
+			sb.AppendText("hello world {0} {1} {2}", "Peter", "Tran", "Foo");
+
+			Assert.Equal("hello world Peter Tran Foo", sb.ToString());
+		}
+
+	}
diff --git a/gistfile2.cs b/gistfile2.cs
@@ -0,0 +1,20 @@
+public class StringBuilder2
+  {
+		private string result = string.Empty;
+
+		public override string ToString()
+		{
+			return this.result;
+		}
+
+		internal void AppendText(string value, params string[] parameters)
+		{
+			this.result += value;
+
+			for (int i = 0; i < parameters.Length; i++)
+			{
+				this.result = this.result.Replace("{" + i + "}", parameters[i]);
+			}
+
+		}
+	}