Add more unit tests for issue 58 (#61)

tests/XPath2.Tests/XPath2.Tests.csproj

@@ -8,6 +8,7 @@
         <GenerateRuntimeConfigurationFiles>true</GenerateRuntimeConfigurationFiles>
         <DebugType>full</DebugType>
         <ProjectGuid>{31DC2EF8-C3FE-467D-84BE-FB5D956E6100}</ProjectGuid>
+        <LangVersion>10</LangVersion>
     </PropertyGroup>
 
     <!--<ItemGroup>

tests/XPath2.Tests/XmlDocumentTests.cs

@@ -0,0 +1,81 @@
+using System.Xml;
+using FluentAssertions;
+using Wmhelp.XPath2;
+using Xunit;
+
+namespace XPath2.Tests;
+
+public class XmlDocumentTests
+{
+    // Issue #58
+    [Theory]
+    [InlineData("max(/R/A/number(@id))")]
+    [InlineData("max(/R/A/@id)")]
+    public void XmlDocument_XPath2Evaluate_MaxFromNumber(string xpath)
+    {
+        // Arrange
+        var doc = GetIssue58();
+
+        // Act
+        var result = doc.XPath2Evaluate(xpath);
+
+        // Assert
+        result.Should().Be(2);
+    }
+
+    // Issue #58
+    [Theory]
+    [InlineData("/R/A[@id=2]")]
+    [InlineData("/R/A[@id='2']")]
+    [InlineData("/R/A[@id=\"2\"]")]
+    public void XmlDocument_SelectNodes_By_Attribute(string xpath)
+    {
+        // Arrange
+        var doc = GetIssue58();
+
+        // Act
+        var result = doc.SelectNodes(xpath);
+
+        // Assert
+        result.Should().HaveCount(1);
+        result![0].OuterXml.Should().Be("<A id=\"2\" />");
+    }
+
+    // Issue #58
+    [Fact(Skip = "System.Xml.XPath.XPathException : Namespace Manager or XsltContext needed. This query has a prefix, variable, or user-defined function.")]
+    public void XmlDocument_SelectNodes_By_AttributeEqualsMaxId_Version1()
+    {
+        // Arrange
+        var doc = GetIssue58();
+
+        // Act
+        var result = doc.SelectNodes("/R/A[@id=max(/R/A/@id)]");
+
+        // Assert
+        result.Should().HaveCount(1);
+        result![0].OuterXml.Should().Be("<A id=\"2\" />");
+    }
+
+    // Issue #58
+    [Fact]
+    public void XmlDocument_SelectNodes_By_AttributeEqualsMaxId_Version2()
+    {
+        // Arrange
+        var doc = GetIssue58();
+
+        // Act
+        var result = doc.SelectNodes("/R/A[not(/R/A/@id > @id)]");
+
+        // Assert
+        result.Should().HaveCount(1);
+        result![0].OuterXml.Should().Be("<A id=\"2\" />");
+    }
+
+    private static XmlDocument GetIssue58()
+    {
+        return new XmlDocument
+        {
+            InnerXml = @"<R><A id=""1""/><A id=""2""/></R>"
+        };
+    }
+}