added GetOrDefault method

Author: robdmoore

NTestDataBuilder.Tests/Builders/BasicCustomerBuilder.cs

@@ -6,7 +6,7 @@ class BasicCustomerBuilder : DataBuilder<Customer, BasicCustomerBuilder>
     {
         public override Customer Build()
         {
-            return new Customer("First Name", "Last Name");
+            return new Customer("First Name", "Last Name", 2013);
         }
     }
 }

NTestDataBuilder.Tests/Entities/Customer.cs

@@ -4,7 +4,7 @@ namespace NTestDataBuilder.Tests.Entities
 {
     public class Customer
     {
-        public Customer(string firstName, string lastName)
+        public Customer(string firstName, string lastName, int yearJoined)
         {
             if (string.IsNullOrEmpty(firstName))
                 throw new ArgumentNullException("firstName");
@@ -13,9 +13,11 @@ public Customer(string firstName, string lastName)
 
             FirstName = firstName;
             LastName = lastName;
+            YearJoined = yearJoined;
         }
 
         public string FirstName { get; private set; }
         public string LastName { get; private set; }
+        public int YearJoined { get; private set; }
     }
 }

NTestDataBuilder.Tests/GetOrDefaultTests.cs

@@ -0,0 +1,43 @@
+using NTestDataBuilder.Tests.Builders;
+using NUnit.Framework;
+
+namespace NTestDataBuilder.Tests
+{
+    class GetOrDefaultTests
+    {
+        private BasicCustomerBuilder _b;
+        const string SetValue = "Value";
+
+        [SetUp]
+        public void Setup()
+        {
+            _b = new BasicCustomerBuilder();
+        }
+
+        [Test]
+        public void GivenAValueHasBeenSetAgainstAProperty_WhenRetrievingTheValueForThatProperty_ThenTheSetValueIsReturned()
+        {
+            _b.Set(x => x.FirstName, SetValue);
+
+            var retrieved = _b.GetOrDefault(x => x.FirstName);
+
+            Assert.That(retrieved, Is.EqualTo(SetValue));
+        }
+
+        [Test]
+        public void GivenNoValueHasBeenSetForAStringProperty_WhenRetrievingTheValueForThatProperty_ThenReturnNull()
+        {
+            var retrieved = _b.GetOrDefault(x => x.FirstName);
+
+            Assert.That(retrieved, Is.EqualTo(null));
+        }
+
+        [Test]
+        public void GivenNoValueHasBeenSetForAnIntProperty_WhenRetrievingTheValueForThatProperty_ThenReturn0()
+        {
+            var retrieved = _b.GetOrDefault(x => x.YearJoined);
+
+            Assert.That(retrieved, Is.EqualTo(0));
+        }
+    }
+}

NTestDataBuilder.Tests/NTestDataBuilder.Tests.csproj

@@ -43,6 +43,7 @@
     <Compile Include="Builders\BasicCustomerBuilder.cs" />
     <Compile Include="BuildTests.cs" />
     <Compile Include="Entities\Customer.cs" />
+    <Compile Include="GetOrDefaultTests.cs" />
     <Compile Include="GetSetTests.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>

NTestDataBuilder/DataBuilder.cs

@@ -65,6 +65,20 @@ public TValue Get<TValue>(Expression<Func<TEntity, TValue>> property)
             return (TValue)_properties[GetPropertyName(property)];
         }
 
+        /// <summary>
+        /// Gets the recorded value for the given property from <see cref="TEntity"/> or if no
+        /// value has been recorded the default value for <see cref="TValue"/>.
+        /// </summary>
+        /// <typeparam name="TValue">The type of the property</typeparam>
+        /// <param name="property">A lambda expression specifying the property to retrieve the recorded value for</param>
+        /// <returns>The recorded value of the property or teh default value for <see cref="TValue"/> if no value recorded</returns>
+        public TValue GetOrDefault<TValue>(Expression<Func<TEntity, TValue>> property)
+        {
+            return Has(property)
+                ? Get(property)
+                : default(TValue);
+        }
+
         /// <summary>
         /// Returns whether or not there is currently a value recorded against the given property from <see cref="TEntity"/>.
         /// </summary>