Keep structuring tests

src/Umbraco.Core/Settable.cs

@@ -0,0 +1,92 @@
+using System;
+
+namespace Umbraco.Core
+{
+    /// <summary>
+    /// Represents a value that can be assigned a value.
+    /// </summary>
+    /// <typeparam name="T">The type of the value</typeparam>
+    public class Settable<T>
+    {
+        private T _value;
+
+        /// <summary>
+        /// Assigns a value to this <see cref="Settable{T}"/> instance.
+        /// </summary>
+        /// <param name="value">The value.</param>
+        public void Set(T value)
+        {
+            HasValue = true;
+            _value = value;
+        }
+
+        /// <summary>
+        /// Assigns a value to this <see cref="Settable{T}"/> instance by copying the value
+        /// of another instance, if the other instance has a value.
+        /// </summary>
+        /// <param name="other">The other instance.</param>
+        public void Set(Settable<T> other)
+        {
+            // set only if has value else don't change anything
+            if (other.HasValue) Set(other.Value);
+        }
+
+        /// <summary>
+        /// Clears the value.
+        /// </summary>
+        public void Clear()
+        {
+            HasValue = false;
+            _value = default (T);
+        }
+
+        /// <summary>
+        /// Gets a value indicating whether a value has been assigned to this <see cref="Settable{T}"/> instance.
+        /// </summary>
+        public bool HasValue { get; private set; }
+
+        /// <summary>
+        /// Gets the value assigned to this <see cref="Settable{T}"/> instance.
+        /// </summary>
+        /// <remarks>An exception is thrown if the HasValue property is false.</remarks>
+        /// <exception cref="InvalidOperationException">No value has been assigned to this instance.</exception>
+        public T Value
+        {
+            get
+            {
+                if (HasValue == false)
+                    throw new InvalidOperationException("The HasValue property is false.");
+                return _value;
+            }
+        }
+
+        /// <summary>
+        /// Gets the value assigned to this <see cref="Settable{T}"/> instance, if a value has been assigned,
+        /// otherwise the default value of <typeparamref name="T"/>.
+        /// </summary>
+        /// <returns>The value assigned to this <see cref="Settable{T}"/> instance, if a value has been assigned,
+        /// else the default value of <typeparamref name="T"/>.</returns>
+        public T ValueOrDefault()
+        {
+            return HasValue ? _value : default(T);
+        }
+
+        /// <summary>
+        /// Gets the value assigned to this <see cref="Settable{T}"/> instance, if a value has been assigned,
+        /// otherwise a specified default value.
+        /// </summary>
+        /// <param name="defaultValue">The default value.</param>
+        /// <returns>The value assigned to this <see cref="Settable{T}"/> instance, if a value has been assigned,
+        /// else <paramref name="defaultValue" />.</returns>
+        public T ValueOrDefault(T defaultValue)
+        {
+            return HasValue ? _value : defaultValue;
+        }
+
+        /// <inheritdoc />
+        public override string ToString()
+        {
+            return HasValue ? _value.ToString() : "void";
+        }
+    }
+}