- Variable types are no longer specified in the call to the `Var`
constructor; they are now specified in the call to `declare`. This
paves the way for supporting variable pattern syntax, in which a
single variable might appear in multiple variable patterns, and have
its type specified in each pattern. The properties `isFinal` and
`isLate` are also moved to `declare` for consistency.
- Variables with inferred types are now specified by simply not
including a type in `declare`; it's no longer necessary to specify
`isImplicitlyTyped: true`.
- `declare` now supports an `expectInferredType` argument to allow the
inferred type of an implicitly typed variable to be tested.
- The tests now check that variables are assigned a type before flow
analysis requests it; previously this was not tested, and the flow
analysis tests sometimes did things in the wrong order. (The
analyzer and CFE have always done this in the proper order though).
- The tests now support some of the crazy types that arise during type
parameter promotion, e.g. they can now distinguish `(T&int)?` from
`T&(int?)`.
- Flow analysis tests now properly replicate the analyzer and CFE
behaviors for converting the static type of an initializer
expression to the corresponding inferred variable type: (a) `Null`
is converted to `dynamic`, and (b) type parameter promotions are
dropped.
Note that this last behavior (dropping type parameter promotions) has
a lot of subtleties, and I'm not convinced the CFE and analyzer do it
soundly in all cases (I've already found one such soundness bug:
https://github.com/dart-lang/sdk/issues/49691). In a later CL, I plan
to add a more thorough set of language tests to verify that we don't
have other lurking soundness issues.
Change-Id: I6f2cd20db1f07b34e0ad4e7002351c8de846b125
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/255600
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
Paul Berry
2b06ac466d