[wasm] Enable System.Xml.Linq.Tests.XTypeDescriptionProviderTests class

[MaximLipnin]

While enabling System.ComponentModel.TypeConverter.Tests on Browser WASM, I faced the failures in System.Xml.Linq.Tests.XTypeDescriptionProviderTests test class.

There are 7 test cases which mostly test the property-related logic for XElement and XAttribute classes (dotnet/corefx#33082).
Those classes are annotated with System.ComponentModel.TypeDescriptionProviderAttribute so that TypeDescriptor.GetProperties() can provide with some additional properties

runtime/src/libraries/System.ComponentModel.TypeConverter/src/MS/Internal/Xml/Linq/ComponentModel/XComponentModel.cs

Lines 36 to 61 in 6072e4d

	public override PropertyDescriptorCollection GetProperties(Attribute[] attributes)
	{
	PropertyDescriptorCollection properties = new PropertyDescriptorCollection(null);
	if (attributes == null)
	{
	if (typeof(T) == typeof(XElement))
	{
	properties.Add(new XElementAttributePropertyDescriptor());
	properties.Add(new XElementDescendantsPropertyDescriptor());
	properties.Add(new XElementElementPropertyDescriptor());
	properties.Add(new XElementElementsPropertyDescriptor());
	properties.Add(new XElementValuePropertyDescriptor());
	properties.Add(new XElementXmlPropertyDescriptor());
	}
	else if (typeof(T) == typeof(XAttribute))
	{
	properties.Add(new XAttributeValuePropertyDescriptor());
	}
	}
	foreach (PropertyDescriptor property in base.GetProperties(attributes))
	{
	properties.Add(property);
	}
	return properties;
	}
	}

.

The mentioned tests get a collection of property descriptors by calling something like below

var xel = new XElement("someElement");
var props = TypeDescriptor.GetProperties(xel);

Actually props contains only a collection of some general properties and doesn't include the additional ones.

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[ericstj]

cc @eerhardt looks like a linker correctness issue.

[eerhardt]

We annotated TypeDescriptionProviderAttribute correctly to preserve the TypeDescriptionProvider types in .NET 5 RC1. However, it appears this usage exposed an ILLinker issue - it doesn't seem to handle generic types correctly. I've logged dotnet/linker#1469 for this.

We won't be able to make progress on this issue in dotnet/runtime since this is an ILLinker issue. Adding blocked.

[eerhardt]

The underlying linker bug has been fixed. Removing "blocked". When we get a new linker in dotnet/runtime, we should be able to enable these tests now.

[MaximLipnin]

#42201 should bring related linker changes

[MaximLipnin]

Tried to run System.ComponentModel.TypeConverter tests on the latest master, which includes changes from #42201, and the failures still exist.
From artifacts/bin/System.ComponentModel.TypeConverter.Tests/net5.0-release/browser-wasm/AppBundle/xharness-output/testResults.xml:

      <test name="System.Xml.Linq.Tests.XTypeDescriptionProviderTests.XElementElementsPropertyDescriptor" type="System.Xml.Linq.Tests.XTypeDescriptionProviderTests" method="XElementElementsPropertyDescriptor" time="0.0057949" result="Fail">
        <failure exception-type="Xunit.Sdk.NotNullException">
          <message><![CDATA[Assert.NotNull() Failure]]></message>
          <stack-trace><![CDATA[   at System.Xml.Linq.Tests.XTypeDescriptionProviderTests.XElementElementsPropertyDescriptor()
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)]]></stack-trace>
        </failure>
      </test>
      <test name="System.Xml.Linq.Tests.XTypeDescriptionProviderTests.XElementAttributePropertyDescriptor" type="System.Xml.Linq.Tests.XTypeDescriptionProviderTests" method="XElementAttributePropertyDescriptor" time="0.000769" result="Fail">
        <failure exception-type="Xunit.Sdk.NotNullException">
          <message><![CDATA[Assert.NotNull() Failure]]></message>
          <stack-trace><![CDATA[   at System.Xml.Linq.Tests.XTypeDescriptionProviderTests.XElementAttributePropertyDescriptor()
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)]]></stack-trace>
        </failure>
      </test>
      <test name="System.Xml.Linq.Tests.XTypeDescriptionProviderTests.XElementValuePropertyDescriptor" type="System.Xml.Linq.Tests.XTypeDescriptionProviderTests" method="XElementValuePropertyDescriptor" time="0.0081339" result="Fail">
        <failure exception-type="Xunit.Sdk.TrueException">
          <message><![CDATA[Assert.True() Failure\nExpected: True\nActual:   False]]></message>
          <stack-trace><![CDATA[   at System.Xml.Linq.Tests.XTypeDescriptionProviderTests.XElementValuePropertyDescriptor()
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)]]></stack-trace>
        </failure>
      </test>
      <test name="System.Xml.Linq.Tests.XTypeDescriptionProviderTests.XAttributeValuePropertyDescriptor" type="System.Xml.Linq.Tests.XTypeDescriptionProviderTests" method="XAttributeValuePropertyDescriptor" time="0.001141" result="Fail">
        <failure exception-type="Xunit.Sdk.TrueException">
          <message><![CDATA[Assert.True() Failure\nExpected: True\nActual:   False]]></message>
          <stack-trace><![CDATA[   at System.Xml.Linq.Tests.XTypeDescriptionProviderTests.XAttributeValuePropertyDescriptor()
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)]]></stack-trace>
        </failure>
      </test>
      <test name="System.Xml.Linq.Tests.XTypeDescriptionProviderTests.XElementDescendantsPropertyDescriptor" type="System.Xml.Linq.Tests.XTypeDescriptionProviderTests" method="XElementDescendantsPropertyDescriptor" time="0.000545" result="Fail">
        <failure exception-type="Xunit.Sdk.NotNullException">
          <message><![CDATA[Assert.NotNull() Failure]]></message>
          <stack-trace><![CDATA[   at System.Xml.Linq.Tests.XTypeDescriptionProviderTests.XElementDescendantsPropertyDescriptor()
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)]]></stack-trace>
        </failure>
      </test>
      <test name="System.Xml.Linq.Tests.XTypeDescriptionProviderTests.XElementXmlPropertyDescriptor" type="System.Xml.Linq.Tests.XTypeDescriptionProviderTests" method="XElementXmlPropertyDescriptor" time="0.0004369" result="Fail">
        <failure exception-type="Xunit.Sdk.NotNullException">
          <message><![CDATA[Assert.NotNull() Failure]]></message>
          <stack-trace><![CDATA[   at System.Xml.Linq.Tests.XTypeDescriptionProviderTests.XElementXmlPropertyDescriptor()
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)]]></stack-trace>
        </failure>
      </test>
      <test name="System.Xml.Linq.Tests.XTypeDescriptionProviderTests.XElementElementPropertyDescriptor" type="System.Xml.Linq.Tests.XTypeDescriptionProviderTests" method="XElementElementPropertyDescriptor" time="0.0006809" result="Fail">
        <failure exception-type="System.NullReferenceException">
          <message><![CDATA[System.NullReferenceException : Object reference not set to an instance of an object.]]></message>
          <stack-trace><![CDATA[   at System.Xml.Linq.Tests.XTypeDescriptionProviderTests.XElementElementPropertyDescriptor()
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)]]></stack-trace>
        </failure>
      </test>

[MaximLipnin]

E.g. XElementElementsPropertyDescriptor test expects a property descriptor named Elements which doesn't exist:

        [Fact]
        public void XElementElementsPropertyDescriptor()
        {
            var xel = new XElement("someElement");
            var props = TypeDescriptor.GetProperties(xel);

            var xelElsPD = props["Elements"];
            Assert.NotNull(xelElsPD);
           // ...

Below is what props has:

FirstAttribute
HasAttributes
HasElements
IsEmpty
LastAttribute
Name
NodeType
Value
FirstNode
LastNode
NextNode
PreviousNode
BaseUri
Document
Parent

[eerhardt]

I got the time to investigate this issue today, and it appears to be another linker issue. I opened dotnet/linker#1536 for this issue. Marking this as blocked again.

[eerhardt]

I retested this scenario with the latest builds and it is still blocked by dotnet/linker#1536.

Note:

            var xel = new XElement("someElement");
            var props = TypeDescriptor.GetProperties(xel);

The call to TypeDescriptor.GetProperties(object) is now marked as "RequiresUnreferencedCode" and using it in a trimmed app will emit a warning. This is because the Type of the object can't be statically analyzed, and thus all the properties of XElement are getting trimmed. Which means the default TypeDescriptor system won't find those properties. So as written, I don't expect this test to work in a trimmed app.

[eerhardt]

Moving to 7.0 as this scenario isn't necessary in order to ship 6.0. The underlying linker issue dotnet/linker#1536 needs to be fixed before this issue can be resolved.

[lewing]

still blocked on dotnet/linker#1536 but that has been raised

[ilonatommy]

Unblocked, if @eerhardt you could see if we are able to close it soon, it would be great.

[lewing]

looks like #70614 should have the linker fix now