No completion for type names after `required`

[stereotype441]

In a fresh dart file, type the following text:

void f({required S})

Place the cursor after the S and request code completions.

Expected result: code completion should offer types like Set, Stream, and String.

Observed result: the only code completion that's offered is switch, which doesn't make any sense in this context.

[bwilkerson]

The code is being interpreted as

void f({required dynamic S}) {}

Completion doesn't provide suggestions for names when the type is dynamic, hence the lack of suggestions.

It should be looking to see that the type is absent and assume that the user might be trying to write a type name.

[FMorschel]

I'll look into this

[FMorschel]

Here is the CL https://dart-review.googlesource.com/c/sdk/+/422903