Swiftlint: explicit_type_interface rule triggered in case let switches

[Hans92]

Xcode 9.3 (9E145)
Swiflint 0.25.1

struct SomeError: Error { }
struct SomeError1: Error { }

let error: Error = Error()

switch error {
    case let error as SomeError:
        // some code
    case let error as SomeError1:
        // some code
}

On every case line I get an error:
"Explicit Type Interface Violation: Properties should have a type interface (explicit_type_interface)".
I can't add here error type. Swift doesn't get it.

I am not sure if this is a bug or I'm doing something wrong.

[marcelofabri]

Maybe we should ignore variables inside cases (source.lang.swift.stmt.case)?

This is the structure that SourceKit returns:

{
          "key.elements" : [
            {
              "key.kind" : "source.lang.swift.structure.elem.pattern",
              "key.length" : 23,
              "key.offset" : 164
            }
          ],
          "key.kind" : "source.lang.swift.stmt.case",
          "key.length" : 29,
          "key.namelength" : 0,
          "key.nameoffset" : 0,
          "key.offset" : 159,
          "key.substructure" : [
            {
              "key.kind" : "source.lang.swift.decl.var.local",
              "key.length" : 5,
              "key.name" : "error",
              "key.namelength" : 5,
              "key.nameoffset" : 168,
              "key.offset" : 168
            }
          ]
        }

[Hans92]

There is also a problem with [weak self] in closures.

[marcelofabri]

Feel free to send a PR!

[ppamorim]

There is a error on case .failure(let error):, Swiftlint warns to set a type, but it is not possible.

[Pikacz]

There is still error on case X.value(let val) but not on case .value(let val)