VS and VS Code Razor Highlighting false negatives

[mikesigs]

I am getting started with Blazor this weekend and I'm finding the Razor highlighting in VS Code to be really bad. It's difficult to work on code when your editor is telling you something is wrong, but the compiler is telling you it's right.

Here are a few examples that all compile and run properly, but show a false positive error with RED highlighting:

Inline Ternary Expression

Inline Lambda Expression

It formats and runs properly without the quotes.

Quoted Handler Function

Again, this formats and runs properly without the quotes.

[javiercn]

@mikesigs thanks for contacting us.

@NTaylorMullen @ryanbrandenburg can you take a look?

[NTaylorMullen]

@mikesigs thanks for the report! We'll be sure to take a peak.

Until we can get VSCode working again for you would you be open to trying Visual Studio 2022 Preview release (assuming you're on windows at least)? Asking because it's free and the issue does not reproduce there.

[winstliu]

So, some notes:

• When the tag is not in a codeblock, Textmate doesn't recognize any of the explicit expression as C#. Semantic highlighting sees the @ transition but that's it.
  
• When the tag is in a codeblock, Textmate sees @onclick as an implicit expression, not an @on{event} attribute. That's when things start to go off the rails because at this point Textmate has no clue we're actually in an attribute, leading to a bunch of "invalid" HTML tokens.
  
  

I also plan to take a look at this one because it's the other big syntax highlighting issue I noticed when trying out Blazor in VS Code.

[winstliu]

I also plan to take a look at this one

(Did some digging and turns out it was removed intentionally with the new tracking issue being #4323.)

[NTaylorMullen]

I also plan to take a look at this one

(Did some digging and turns out it was removed intentionally with the new tracking issue being #4323.)

Ah not necessarily "intentionally" it's just that in order to make this scenario work for TextMate we'd need to hardcode the understanding of @ based attributes and which ones apply. Currently the Blazor runtime declares runtime based components which tell us which @ attributes are "real" and which ones aren't. Based on that knowledge we apply semantic colorization to override what TextMate views. That being said we don't have that support in VSCode yet.

I think our best case route for this would be to ensure TextMate could recover gracefully to ensure that semantic colorization (when we're able to bring it to VSCode) can change colors without destroying the remainder of the TextMate understanding

[ryanbrandenburg]

When we fix this lets be sure to check that it fixes VS's behavior as well.

[rfrancisco]

Any updates on this issue?

[allisonchou]

This should be fixed via #9336