Include digits after first letter in Urilize (for Auto-Identifiers)

Added dependency: NUnit3TestAdapter (for VS Test Runner)
Disabled "Prefer 32-bit" on Markdig.Tests to accommodate NUnit.

src/Markdig.Tests/Markdig.Tests.csproj

@@ -24,6 +24,7 @@
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -100,6 +101,7 @@
   </ItemGroup>
   <ItemGroup>
     <Service Include="{508349B6-6B84-4DF5-91F0-309BEEBAD82D}" />
+    <Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 

src/Markdig.Tests/TestLinkHelper.cs

@@ -297,5 +297,102 @@ public void TestAutolinkInvalid()
             Assert.False(LinkHelper.TryParseAutolink(new StringSlice(@"<ab"), out text, out isEmail));
             Assert.False(LinkHelper.TryParseAutolink(new StringSlice(@"<user@>"), out text, out isEmail));
         }
+
+        [TestCase("Header identifiers in HTML", "header-identifiers-in-html")]
+        [TestCase("* Dogs*?--in *my* house?", "dogs-in-my-house")] // Not Pandoc equivalent: dogs--in...
+        [TestCase("[HTML], [S5], or [RTF]?", "html-s5-or-rtf")]
+        [TestCase("3. Applications", "applications")]
+        [TestCase("33", "")]
+        public void TestUrilizeNonAscii_Pandoc(string input, string expectedResult)
+        {
+            Assert.AreEqual(expectedResult, LinkHelper.Urilize(input, false));
+        }
+
+        [TestCase("abc", "abc")]
+        [TestCase("a-c", "a-c")]
+        [TestCase("a c", "a-c")]
+        [TestCase("a_c", "a_c")]
+        [TestCase("a.c", "a.c")]
+        [TestCase("a,c", "ac")]
+        [TestCase("a--", "a")] // Not Pandoc-equivalent: a--
+        [TestCase("a__", "a")] // Not Pandoc-equivalent: a__
+        [TestCase("a..", "a")] // Not Pandoc-equivalent: a..
+        [TestCase("a??", "a")]
+        [TestCase("a  ", "a")]
+        [TestCase("a--d", "a-d")]
+        [TestCase("a__d", "a_d")]
+        [TestCase("a??d", "ad")]
+        [TestCase("a  d", "a-d")]
+        [TestCase("a..d", "a.d")]
+        [TestCase("-bc", "bc")]
+        [TestCase("_bc", "bc")]
+        [TestCase(" bc", "bc")]
+        [TestCase("?bc", "bc")]
+        [TestCase(".bc", "bc")]
+        [TestCase("a-.-", "a")] // Not Pandoc equivalent: a-.-
+        public void TestUrilizeOnlyAscii_Simple(string input, string expectedResult)
+        {
+            Assert.AreEqual(expectedResult, LinkHelper.Urilize(input, true));
+        }
+
+        [TestCase("bær", "br")]
+        [TestCase("bør", "br")]
+        [TestCase("bΘr", "br")]
+        [TestCase("四五", "")]
+        public void TestUrilizeOnlyAscii_NonAscii(string input, string expectedResult)
+        {
+            Assert.AreEqual(expectedResult, LinkHelper.Urilize(input, true));
+        }
+
+        [TestCase("bár", "bar")]
+        [TestCase("àrrivé", "arrive")]
+        public void TestUrilizeOnlyAscii_Normalization(string input, string expectedResult)
+        {
+            Assert.AreEqual(expectedResult, LinkHelper.Urilize(input, true));
+        }
+
+        [TestCase("123", "")]
+        [TestCase("1,-b", "b")]
+        [TestCase("b1,-", "b1")] // Not Pandoc equivalent: b1-
+        [TestCase("ab3", "ab3")]
+        [TestCase("ab3de", "ab3de")]
+        public void TestUrilizeOnlyAscii_Numeric(string input, string expectedResult)
+        {
+            Assert.AreEqual(expectedResult, LinkHelper.Urilize(input, true));
+        }
+
+        [TestCase("一二三四五", "一二三四五")]
+        [TestCase("一,-b", "一-b")]
+        public void TestUrilizeNonAscii_NonAsciiNumeric(string input, string expectedResult)
+        {
+            Assert.AreEqual(expectedResult, LinkHelper.Urilize(input, false));
+        }
+
+        [TestCase("bær", "bær")]
+        [TestCase("æ5el", "æ5el")]
+        [TestCase("-æ5el", "æ5el")]
+        [TestCase("-frø-", "frø")]
+        [TestCase("-fr-ø", "fr-ø")]
+        public void TestUrilizeNonAscii_Simple(string input, string expectedResult)
+        {
+            Assert.AreEqual(expectedResult, LinkHelper.Urilize(input, false));
+        }
+
+        // Just to be sure, test for characters expressly forbidden in URI fragments:
+        [TestCase("b#r", "br")]
+        [TestCase("b%r", "br")] // Invalid except as an escape character
+        [TestCase("b^r", "br")]
+        [TestCase("b[r", "br")]
+        [TestCase("b]r", "br")]
+        [TestCase("b{r", "br")]
+        [TestCase("b}r", "br")]
+        [TestCase("b<r", "br")]
+        [TestCase("b>r", "br")]
+        [TestCase(@"b\r", "br")]
+        [TestCase(@"b""r", "br")]
+        public void TestUrilizeNonAscii_NonValidCharactersForFragments(string input, string expectedResult)
+        {
+            Assert.AreEqual(expectedResult, LinkHelper.Urilize(input, false));
+        }
     }
 }

src/Markdig.Tests/project.json

@@ -18,6 +18,7 @@
     }
   },
   "dependencies": {
-    "NUnit": "3.2.0"
+    "NUnit": "3.2.0",
+    "NUnit3TestAdapter": "3.2.0"
   }
 }

src/Markdig/Helpers/LinkHelper.cs

@@ -61,6 +61,11 @@ public static string Urilize(string headingText, bool allowOnlyAscii)
                         }
                         previousIsSpace = false;
                     }
+                    else if (c.IsDigit())
+                    {
+                        headingBuffer.Append(c);
+                        previousIsSpace = false;
+                    }
                     else if (!previousIsSpace && c.IsWhitespace())
                     {
                         var pc = headingBuffer[headingBuffer.Length - 1];