Added named group for env: in the FormatWith Regex, removed out parameter from CheckAndFormatString

Author: ruhullahshah

src/GitVersionCore/OutputVariables/VariableProvider.cs

@@ -43,17 +43,14 @@ public static VersionVariables GetVariablesFor(SemanticVersion semanticVersion,
 
             var semverFormatValues = new SemanticVersionFormatValues(semanticVersion, config);
 
-            string informationalVersion;
-            CheckAndFormatString(config.AssemblyInformationalFormat, semverFormatValues, semverFormatValues.DefaultInformationalVersion,
-                "AssemblyInformationalVersion", out informationalVersion);
+            string informationalVersion = CheckAndFormatString(config.AssemblyInformationalFormat, semverFormatValues,
+                semverFormatValues.DefaultInformationalVersion, "AssemblyInformationalVersion");
 
-            string assemblyFileSemVer;
-            CheckAndFormatString(config.AssemblyFileVersioningFormat, semverFormatValues, semverFormatValues.AssemblyFileSemVer,
-                "AssemblyFileVersioningFormat", out assemblyFileSemVer);
+            string assemblyFileSemVer = CheckAndFormatString(config.AssemblyFileVersioningFormat, semverFormatValues,
+                semverFormatValues.AssemblyFileSemVer, "AssemblyFileVersioningFormat");
 
-            string assemblySemVer;
-            CheckAndFormatString(config.AssemblyVersioningFormat, semverFormatValues, semverFormatValues.AssemblySemVer,
-                "AssemblyVersioningFormat", out assemblySemVer);
+            string assemblySemVer = CheckAndFormatString(config.AssemblyVersioningFormat, semverFormatValues,
+                semverFormatValues.AssemblySemVer, "AssemblyVersioningFormat");
 
             var variables = new VersionVariables(
                 semverFormatValues.Major,
@@ -95,8 +92,10 @@ static void PromoteNumberOfCommitsToTagNumber(SemanticVersion semanticVersion)
             semanticVersion.BuildMetaData.CommitsSinceTag = null;
         }
 
-        static void CheckAndFormatString<T>(string formatString, T source,  string defaultValue, string formatVarName, out string formattedString)
+        static string CheckAndFormatString<T>(string formatString, T source,  string defaultValue, string formatVarName)
         {
+            string formattedString;
+
             if (string.IsNullOrEmpty(formatString))
             {
                 formattedString = defaultValue;
@@ -112,6 +111,8 @@ static void CheckAndFormatString<T>(string formatString, T source,  string defau
                     throw new WarningException(string.Format("Unable to format {0}.  Check your format string: {1}", formatVarName, formex.Message));
                 }
             }
+
+            return formattedString;
         }
     }
 }

src/GitVersionCore/StringFormatWith.cs

@@ -8,7 +8,7 @@ namespace GitVersion
 
     static class StringFormatWithExtension
     {
-        private static readonly Regex TokensRegex = new Regex(@"{(env:)??\w+(\s+(\?\?)??\s+\w+)??}", RegexOptions.Compiled);
+        private static readonly Regex TokensRegex = new Regex(@"{(?<env>env:)??\w+(\s+(\?\?)??\s+\w+)??}", RegexOptions.Compiled);
 
         /// <summary>
         ///     Formats a string template with the given source object.
@@ -27,18 +27,17 @@ public static string FormatWith<T>(this string template, T source)
 
             // {MajorMinorPatch}+{Branch}
             var objType = source.GetType();
-            const string ENV_VAR_INDICATOR = "env:";
             foreach (Match match in TokensRegex.Matches(template))
             {
                 var memberAccessExpression = TrimBraces(match.Value);
                 string propertyValue = null;
 
                 // Support evaluation of environment variables in the format string
-                // For example: {env:JENKINS_BUILD_NUMBER??fall-back-string}
+                // For example: {env:JENKINS_BUILD_NUMBER ?? fall-back-string}
 
-                if (memberAccessExpression.StartsWith(ENV_VAR_INDICATOR))
+                if (match.Groups["env"].Success)
                 {
-                    memberAccessExpression = memberAccessExpression.TrimStart(ENV_VAR_INDICATOR.ToCharArray()).TrimEnd(ENV_VAR_INDICATOR.ToCharArray());
+                    memberAccessExpression = memberAccessExpression.Substring(memberAccessExpression.IndexOf(':') + 1);
                     string envVar = memberAccessExpression, fallback = null;
                     string[] components = (memberAccessExpression.Contains("??")) ? memberAccessExpression.Split(new string[] { "??" }, StringSplitOptions.None) : null;
                     if (components != null)