Previously, intersections were only allowed as targets, but this was
just an artifact of the original implementation, which operated inside
the structural part of isRelatedTo. Removing this restriction catches
subtle bugs in React user code, where a function named `create` returns
a mapped type whose types are all branded numbers. The display of these
properties, for some original type `T`, is not `number & { __ }` but
the much-less-obvious `RegisteredStyle<T>`.
Previously, getWidenedTypedFromJSPropertyAssignment was not called for
Typescript code. Since property assignments on functions, it is. That
meant that property assignments would incorrectly create a JS container
for empty object literals in a property assignment, even in Typescript:
```ts
const one = () => 1
one.p = {}
one.p.q = {} // should not work in Typescript!
```
Now empty object literals never create expando objects in Typescript,
because getJSExpandoObjectType requires the declaration to be in a JS
file.
* Use context free expression types in evolving array checking and cache context free type
* Simplify second test
* Low max depth a tad just so node 8 wont stack out
* By request make flow control a round number
skipping narrowing if the old algorithm produces a type to which the
assigned type is not assignable.
This also means we'll no longer narrow for erroneous assignments where
the assigned type is not assignable to the declared type. This is the
reason for the numericLiteralTypes3 baseline change.
Fixes#26405.
* Allow special property assignments in TS
But only for functions and constant variable declarations initialised with
functions.
This specifically excludes class declarations and class expressions,
which differs from Javascript. That's because Typescript supports
`static` properties, which are equivalent to property assignments to a
class.
* Improve contextual typing predicate
Don't think it's right yet, but probably closer?
* More fixes.
The code is still fantastically ugly, but everything works the way it
should.
Also update baselines, even where it is ill-advised.
* Cleanup
* Remove extra whitespace
* Some kind of fix to isAnyDeclarationName
It's not done yet.
Specifically, in TS:
Special property assignments are supposed to be declaration sites (but not all
top-level assignments), and I think I
got them to be. (But not sure).
In JS:
Special property assignments are supposed to be declaration sites (but not all
top-level assignments), and I'm pretty sure ALL top-level assignments
have been declaration sites for some time. This is incorrect, and
probably means the predicate needs to be the same for both dialects.
* Add fourslash and improve isAnyDeclarationName
Now JS behaves the same as TS.
* Cleanup from PR comments
* This-property w/empty object init: use type annotation
* JS initializer type doesn't apply to this-property assignments
* Move getJSExpandoType into getWidenedType* functions
Plus some cleanup.
* Improved style from PR comments
* Parameters are not expando
Anders Hejlsberg
Ryan Cavanaugh
Nathan Shively-Sanders
Wenlu Wang
csigs
Andy
Klaus Meinhardt
Wesley Wigham
Ron Buckton
David Sherret
Matt McCutchen
Sheetal Nandi
Tim Schaub
Daniel Rosenwasser