Fixing issue TestStack#226. Now handles numbers and throws for some o…

…ther characters that are not supported in examples.

src/TestStack.BDDfy.Tests/NetToStringTests.cs

@@ -1,3 +1,4 @@
+using System;
 using Shouldly;
 using TestStack.BDDfy.Configuration;
 using Xunit;
@@ -55,6 +56,8 @@ public void OneLetterWordInTheBeginningOfStringIsTurnedIntoAWord()
         [Theory]
         [InlineData("GivenThereAre__start__Cucumbers", "Given there are <start> cucumbers")]
         [InlineData("Given_there_are__start__cucumbers", "Given there are <start> cucumbers")]
+        [InlineData("GivenThereAre__count1__Cucumbers", "Given there are <count 1> cucumbers")]
+        [InlineData("Given_there_are__count2__cucumbers", "Given there are <count2> cucumbers")] // The spacing rules for numbers are not consequential
         [InlineData("GivenMethodTaking__ExampleInt__", "Given method taking <example int>")]
         [InlineData("Given_method_taking__ExampleInt__", "Given method taking <ExampleInt>")]
         [InlineData("__starting__with_example", "<starting> with example")]
@@ -67,5 +70,16 @@ public void CanDealWithExampleStepNames(string stepName, string expectedStepTitl
         {
             NetToString.Convert(stepName).ShouldBe(expectedStepTitle, Case.Sensitive);
         }
+
+        [Theory]
+        [InlineData("GivenThereAre__två__Cucumbers", "Given there are <två> cucumbers")]
+        public void ReportsIllegalExampleStepNames(string stepName, string expectedStepTitle) {
+            var exception = Record.Exception(() => {
+                NetToString.Convert(stepName).ShouldBe(expectedStepTitle, Case.Sensitive);
+            });
+
+            Assert.NotNull(exception);
+            Assert.IsType<ArgumentException>(exception);
+        }
     }
 }

src/TestStack.BDDfy/NetToString.cs

@@ -49,11 +49,11 @@ private static bool ShouldAddSpace(char lastChar, char currentChar)
             return false;
         }
 
-        public static readonly Func<string, string> Convert = name =>
-        {
-            if (name.Contains("__"))
-                return ExampleTitle(name);
+        public static readonly Func<string, string> Convert = name => {
+            return name.Contains("__") ? ExampleTitle(name) : ConvertNonExample(name);
+        };
 
+        private static readonly Func<string, string> ConvertNonExample = name => {
             if (name.Contains("_"))
                 return FromUnderscoreSeparatedWords(name);
 
@@ -62,11 +62,16 @@ private static bool ShouldAddSpace(char lastChar, char currentChar)
 
         private static string ExampleTitle(string name)
         {
-            name = Regex.Replace(name, "__([a-zA-Z]+)__", " <$1> ");
+            // Compare contains("__") with a regex match
+            string newName = Regex.Replace(name, "__([a-zA-Z][a-zA-Z0-9]*)__", " <$1> ");
+
+            if (newName == name) {
+                throw new ArgumentException("Illegal example title in name '" + name + "'!");
+            }
 
             // for when there are two consequetive example placeholders in the word; e.g. Given__one____two__parameters
-            name = name.Replace("  ", " ");
-            return Convert(name).Trim();
+            newName = newName.Replace("  ", " ");
+            return Convert(newName).Trim();
         }
     }
 }