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The Dart SDK, including the VM, JS and Wasm compilers, analysis, core libraries, and more.
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What should `OmittedTypeAnnotation.code` produce? #55677

Open jakemac53 opened 4 months ago

jakemac53 commented 4 months ago

Today, it ends up putting the OmittedTypeAnnotation directly into the code.

We could keep that, and possibly just change the toString() of OmittedTypeAnnotation, but that seems a bit weird.

In https://dart-review.googlesource.com/c/sdk/+/365960/1 I tried to change the code object to just the string <omitted>, but that broke various tests - it looks like we are actually putting in the inferred type eventually through some magic smarts, at least in some scenarios. But, I don't really understand the mechanisms at play here.

cc @johnniwinther

johnniwinther commented 4 months ago

In phase 1+2 augmentation libraries the omitted types are generated as OmittedType1, OmittedType2, etc and replaced with the inferred type in phase 3 and merged augmentation libraries. I think we assert or throw if the type isn't inferred.

jakemac53 commented 4 months ago

Ok, so you do expect to get the actual OmittedTypeAnnotation back? I could just update the Code API docs to say that these are also valid.

johnniwinther commented 4 months ago

The OmittedTypeAnnotation is a valid value. We should though always be able to generate the actual type in phase 3 (we even have an assert for this).

Do you see this is in the merged augmentation library?

jakemac53 commented 4 months ago

I haven't seen any actual issues with this to be clear, I was just surprised to see the actual type annotations. All Code objects have a list of parts, which are documented as being only Identifier, String, and Code. But it does make sense that these are allowed, so I will just update the docs that they can also be OmittedTypeAnnotations.

jakemac53 commented 4 months ago

Fwiw I actually ran into this because of an extension I had written on code objects, to emit a debug string, which didn't handle OmittedTypeAnnotation objects, so it fell back on toString().