test/decl/protocol/conforms/redundant_conformance.swift

// RUN: %empty-directory(%t)

// RUN: %target-swift-frontend -emit-module -o %t %S/Inputs/redundant_conformance_A.swift
// RUN: %target-swift-frontend -emit-module -o %t -I %t %S/Inputs/redundant_conformance_B.swift
// RUN: %target-typecheck-verify-swift -I %t

import redundant_conformance_A
import redundant_conformance_B

extension ConformsToP
  : P1 { // expected-warning{{conformance of 'ConformsToP' to protocol 'P1' was already stated in the type's module 'redundant_conformance_A'}}
  typealias A = Double // expected-note{{type alias 'A' will not be used to satisfy the conformance to 'P1'}}

  func f() -> Double { return 0.0 } // expected-note{{instance method 'f()' will not be used to satisfy the conformance to 'P1'}}
       // expected-note@-1{{found this candidate}}
}

extension ConformsToP
  : P2 { // expected-warning{{conformance of 'ConformsToP' to protocol 'P2' was already stated in the protocol's module 'redundant_conformance_B'}}
}

extension OtherConformsToP : P1 { // expected-error{{redundant conformance of 'OtherConformsToP' to protocol 'P1'}}
  func f() -> Int { return 0 }
}

func testConformsToP(cp1: ConformsToP, ocp1: OtherConformsToP) {
  // Note:
  let _ = cp1.f()  // expected-error{{ambiguous use of 'f()'}}

  let _ = ocp1.f() // okay: picks "our" OtherConformsToP.f()
}

// slightly different error messages for conditional conformances:

extension GenericConformsToP: P1 where T: P1 {
// expected-warning@-1{{conformance of 'GenericConformsToP<T>' to protocol 'P1' conflicts with that stated in the type's module 'redundant_conformance_A' and will be ignored; there cannot be more than one conformance, even with different conditional bounds}}
    typealias A = Double
    // expected-note@-1{{type alias 'A' will not be used to satisfy the conformance to 'P1'}}
    func f() -> Double { return 0.0 }
    // expected-note@-1{{instance method 'f()' will not be used to satisfy the conformance to 'P1'}}
}
extension GenericConformsToP: P2 where T: P1 {
    // expected-warning@-1{{conformance of 'GenericConformsToP<T>' to protocol 'P2' conflicts with that stated in the protocol's module 'redundant_conformance_B' and will be ignored; there cannot be more than one conformance, even with different conditional bounds}}
}

extension OtherGenericConformsToP: P1 where T: P1 {
// expected-error@-1{{conflicting conformance of 'OtherGenericConformsToP<T>' to protocol 'P1'; there cannot be more than one conformance, even with different conditional bounds}}
    typealias A = Double
    func f() -> Double { return 0.0 }
}

extension GenericConditionalConformsToP: P1 {
// expected-warning@-1{{conformance of 'GenericConditionalConformsToP<T>' to protocol 'P1' conflicts with that stated in the type's module 'redundant_conformance_A' and will be ignored; there cannot be more than one conformance, even with different conditional bounds}}
    typealias A = Double
    // expected-note@-1{{type alias 'A' will not be used to satisfy the conformance to 'P1'}}
    func f() -> Double { return 0.0 }
    // expected-note@-1{{instance method 'f()' will not be used to satisfy the conformance to 'P1'}}
}
extension GenericConditionalConformsToP: P2 {
    // expected-warning@-1{{conformance of 'GenericConditionalConformsToP<T>' to protocol 'P2' conflicts with that stated in the protocol's module 'redundant_conformance_B' and will be ignored; there cannot be more than one conformance, even with different conditional bounds}}
}

extension OtherGenericConditionalConformsToP: P1 {
// expected-error@-1{{conflicting conformance of 'OtherGenericConditionalConformsToP<T>' to protocol 'P1'; there cannot be more than one conformance, even with different conditional bounds}}
    typealias A = Double
    func f() -> Double { return 0.0 }
}

// FB6114209: spurious ambiguity errors
protocol MyUsefulProtocol {
  var someInt: Int { get }
}

class Class1 {
  typealias ProviderOne = MyUsefulProtocol
}

class Class2 {
  typealias ProviderTwo = MyUsefulProtocol
}

class Class3 {
  typealias ProviderThree = Class1.ProviderOne & Class2.ProviderTwo
}

class SomeMockClass: Class3.ProviderThree { // okay
  var someInt: Int = 5
}