[SR-11120] [5.1] [property wrapper] attribute lookup does not include typealiases

[swift-ci]

Previous ID	SR-11120
Radar	rdar://problem/53107788
Original Reporter	tannernelson (JIRA User)
Type	Bug
Status	Resolved
Resolution	Done

Environment

swift-5.1-DEVELOPMENT-SNAPSHOT-2019-07-11-a-osx.pkg
macOS 10.15 Beta
Xcode 11.0 beta 2

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Bug
Assignee	@theblixguy
Priority	Medium

md5: deb0a1f058605397bf4708d8c6f58bc2

duplicates:

• SR-11288 Property wrappers aren't inherited as type aliases

relates to:

• SR-11131 Nested protocolWrappers can't be typealias'ed when parent type is generic

Issue Description:

Assuming the following code:

public protocol Model { }

@propertyWrapper
public struct ModelField<M, V>
    where M: Model, V: Codable
{
    public init() { }
    
    public var wrappedValue: V {
        get { fatalError() }
        set { fatalError() }
    }
}

extension Model {
    public typealias Field<V> = ModelField<Self, V>
        where V: Codable
}

The typealias for `Field` is not respected when looking up attributes:

struct Planet: Model {
    @Field var name: String
}

error: unknown attribute 'Field'
    @Field var name: String
    ^

[belkadan]

@swift-ci create

[swift-ci]

Comment by tanner0101 (JIRA)

Do you think this bug will be fixed in 5.1?

[swift-ci]

Comment by tanner0101 (JIRA)

@belkadan / @DougGregor any updates on this?

[theblixguy]

Fixed here: #26795