[SR-7293] Swift local refactoring: Customize Equatable Conformance #49841

nkcsgexi · 2018-03-27T23:53:12Z


Previous ID	SR-7293
Radar	None
Original Reporter	@nkcsgexi
Type	New Feature
Status	Closed
Resolution	Done

Additional Detail from JIRA


Votes	0
Component/s	Source Tooling
Labels	New Feature, Refactoring, StarterBug
Assignee	andrewtkachuk (JIRA)
Priority	Medium

md5: afc6ec2379362a2c31c09e7d29216645

relates to:

SR-7291 Swift local refactoring: adding Hashable conformances automatically

Issue Description:

A typical way of implementing equatable conformance is to check equal for all fields. A local refactoring can be implemented to help this pattern, e.g.

// Right click on the declared name Animal and apply "adding Equatable 
// conformance" refactoring. 
class Animal {
 var age: Int
 var kind: AnimalKind
 var gender: Gender
 init(age: Int, kind: AnimalKind, gender: Gender) {
   self.age = age
   self.kind = kind
   self.gender = gender
 }
}

When a user right-clicks the declared name "Animal", an available refactoring "adding Equatable conformance" appears. After applying the refactoring, the above code snippet transforms to:

// Right click on the declared name Animal and apply "adding Equatable 
// conformance" refactoring. 
class Animal: Equatable {
  var age: Int
  var kind: AnimalKind
  var gender: Gender
  init(age: Int, kind: AnimalKind, gender: Gender) {
    self.age = age
    self.kind = kind
    self.gender = gender
  }
  // Auto-generated function
  static func == (lhs: Animal, rhs: Animal) -> Bool {
    return lhs.age == rhs.age &&
           lhs.kind == rhs.kind &&
           lhs.gender == rhs.gender
  }
}

This code after transformation may not be the end outcome the user expected. However, they can always adjust if needed.

belkadan · 2018-03-28T16:55:18Z

This is no longer needed for structs and enums. Do you think it's worth having for classes, though? cc @allevato

belkadan · 2018-03-28T16:57:46Z

I suppose one possible use is to make it explicit so you can modify it.

allevato · 2018-03-30T04:38:41Z

I agree—given that there's no annotation or other mechanism to exclude individual properties from ==, a local refactor would still be a valuable time-saver for users who want to generate it and then strip out a couple of the properties.

swift-ci · 2018-07-31T23:40:36Z