Adding a unit test for FormatWith method

Author: ruhullahshah

src/GitVersionCore.Tests/GitVersionCore.Tests.csproj

@@ -143,6 +143,7 @@
     <Compile Include="Helpers\PathHelper.cs" />
     <Compile Include="IntegrationTests\MasterScenarios.cs" />
     <Compile Include="SemanticVersionTests.cs" />
+    <Compile Include="StringFormatWithExtensionTests.cs" />
     <Compile Include="TestableVersionVariables.cs" />
     <Compile Include="TestEffectiveConfiguration.cs" />
     <Compile Include="TestFileSystem.cs" />

src/GitVersionCore.Tests/StringFormatWithExtensionTests.cs

@@ -0,0 +1,75 @@
+using System;
+
+using GitVersion;
+using NUnit.Framework;
+
+namespace GitVersionCore.Tests
+{
+    [TestFixture]
+
+    public class StringFormatWithExtensionTests
+    {
+        [Test]
+        public void FormatWith_NoTokens()
+        {
+            var propertyObject = new { };
+            var target = "Some String without tokens";
+            var expected = target;
+            var actual = target.FormatWith(propertyObject);
+            Assert.AreEqual(expected, actual);
+        }
+
+        [Test]
+        public void FormatWith_SingleSimpleToken()
+        {
+            var propertyObject = new { SomeProperty = "SomeValue" };
+            var target = "{SomeProperty}";
+            var expected = "SomeValue";
+            var actual = target.FormatWith(propertyObject);
+            Assert.AreEqual(expected, actual);
+        }
+
+        [Test]
+        public void FormatWith_MultipleTokensAndVerbatimText()
+        {
+            var propertyObject = new { SomeProperty = "SomeValue", AnotherProperty = "Other Value" };
+            var target = "{SomeProperty} some text {AnotherProperty}";
+            var expected = "SomeValue some text Other Value";
+            var actual = target.FormatWith(propertyObject);
+            Assert.AreEqual(expected, actual);
+        }
+
+        [Test]
+        public void FormatWith_EnvVarToken()
+        {
+            Environment.SetEnvironmentVariable("GIT_VERSION_TEST_VAR", "Env Var Value");
+            var propertyObject = new { };
+            var target = "{$GIT_VERSION_TEST_VAR}";
+            var expected = "Env Var Value";
+            var actual = target.FormatWith(propertyObject);
+            Assert.AreEqual(expected, actual);
+        }
+
+        [Test]
+        public void FormatWith_EnvVarTokenWithFallback()
+        {
+            Environment.SetEnvironmentVariable("GIT_VERSION_TEST_VAR", "Env Var Value");
+            var propertyObject = new { };
+            var target = "{$GIT_VERSION_TEST_VAR??fallback}";
+            var expected = "Env Var Value";
+            var actual = target.FormatWith(propertyObject);
+            Assert.AreEqual(expected, actual);
+        }
+
+        [Test]
+        public void FormatWith_UnsetEnvVarTokenWithFallback()
+        {
+            Environment.SetEnvironmentVariable("GIT_VERSION_UNSET_TEST_VAR", null);
+            var propertyObject = new { };
+            var target = "{$GIT_VERSION_UNSET_TEST_VAR??fallback}";
+            var expected = "fallback";
+            var actual = target.FormatWith(propertyObject);
+            Assert.AreEqual(expected, actual);
+        }
+    }
+}