After update to AngleSharp 1.1.0: 'No source reference attached to test element, cannot determine element tag closing style.'
SebastianStehle opened this issue · comments
Bug Report
Prerequisites
- Can you reproduce the problem in a MWE?
- Are you running the latest version of AngleSharp?
- Did you check the FAQs to see if that helps you?
- Are you reporting to the correct repository? (there are multiple AngleSharp libraries, e.g.,
AngleSharp.Cssfor CSS support) - Did you perform a search in the issues?
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Description
I have updated to AngleSharp 1.1.0 from 1.0.7 and now I get the following error.
Message:
System.InvalidOperationException : No source reference attached to test element, cannot determine element tag closing style.
Stack Trace:
ElementComparer.Compare(Comparison& comparison, CompareResult currentDecision)
DiffingStrategyPipeline.Compare[TComparison](TComparison& comparison, List`1 compareStrategies, CompareResult initialResult)
DiffingStrategyPipeline.Compare(Comparison& comparison)
IDiffingStrategy.Compare(Comparison& comparison)
HtmlDifferenceEngine.CompareElement(Comparison& comparison)
HtmlDifferenceEngine.CompareNode(Comparison& comparison)
HtmlDifferenceEngine.<CompareNodes>b__11_0(Comparison comparison)
SelectManySingleSelectorIterator`2.MoveNext()
Steps to Reproduce
Very simple example:
var actual = "<div></div>";
var expected = "<div></div>";
var diffs =
DiffBuilder
.Compare(actual)
.WithTest(expected)
.WithOptions(options =>
{
options.AddElementComparer(true);
options.AddSearchingNodeMatcher();
})
.Build().ToList();
Expected behavior: No error.
Actual behavior: [What actually happened]
Environment details: [OS, .NET Runtime, ...]
AngleSharp.Diffing: 0.18.2
Possible Solution
[Optionally, share your idea to fix the issue]
I am not sure what has changed with the latest AngleSharp to cause this. The DiffBuilder's parser has IsKeepingSourceReferences = true set, so that should take care of that exception.
The part of the code that causes the expectation to be thrown is this: if (testElement.SourceReference is not HtmlTagToken testTag).
@FlorianRappl do you have some insights here?
Yes, I have expected that there would have been a bug with this property, so I tested it and the source reference is actually there. At least in my test
Yes, I think this is a problem (not that it's null - it is not - but the test fails as its no longer an HtmlTagToken).
It was introduced here: AngleSharp/AngleSharp#1159
Actually I am not sure if its a breaking change (in my eyes it kind of is, but then again the ISourceReference has not reflected what type is underneath - so it should not be used like that). Overall it seemed I did not pay close enough attention to this detail when accepting the PR.
I need to investigate if this new SourceReference type is really needed. I think this was an optimization to remove the tokens - thus lower the pressure.
Question to you @egil - is this (HtmlTagToken) fully required? Is the text position information enough?
@FlorianRappl it is only needed to determine if a tag is self-closing or not:
If there is another way to get that information without a HtmlTagToken I'm fine with removing the need for source references.
@SebastianStehle if you do not need the differ to tell you if tags using different closing styles, you can disable that check by calling .AddElementComparer(enforceTagClosing: false).
Unfortunately I need that.
If there is another way to get that information without a HtmlTagToken I'm fine with removing the need for source references.
I don't think so. Just to be clear: You need to know if it's <foo></foo> or <foo />?
Effectively, there should be no difference (from the parsing perspective there is a lot of difference - in real / official HTML5 only a few elements can be self-closed - and all of them should actually be self-closed without the trailing slash - for example <img> is OK and <img /> is just "tolerated" and not good).
I've pushed an update. With this latest preview it should work again.
@SebastianStehle can you try to upgrade AngleSharp to 1.1.1-beta.387. Once I have confirmation that this solves the issue I'd make a full release of AngleSharp 1.1.1.
If there is another way to get that information without a HtmlTagToken I'm fine with removing the need for source references.
I don't think so. Just to be clear: You need to know if it's
<foo></foo>or<foo />?Effectively, there should be no difference (from the parsing perspective there is a lot of difference - in real / official HTML5 only a few elements can be self-closed - and all of them should actually be self-closed without the trailing slash - for example
<img>is OK and<img />is just "tolerated" and not good).
I understand that. The challenge is that some users want to know if two HTML snippets are the same, down to whether or not tags are self-closing or not. By default AngleSharp.Diffing do not consider the self-closingness of elements when it compares them.
Any update @SebastianStehle ?
I will test it out today.
I think we can close this - this is fixed with AngleSharp 1.1.1.
Closing now - if this is not true please let us know. Thanks!