Merge pull request #131 from unsignedapps/equatable-computed-properties

Don't generate Equatable checking for computed properties

Author: bok-

Sources/VexilMacros/FlagContainerMacro.swift

@@ -146,7 +146,7 @@ extension FlagContainerMacro: ExtensionMacro {
                     extendedType: type,
                     inheritanceClause: .init(inheritedTypes: [ .init(type: TypeSyntax(stringLiteral: "Equatable")) ])
                 ) {
-                    var variables = declaration.memberBlock.variables
+                    var variables = declaration.memberBlock.storedVariables
                     if variables.isEmpty == false {
                         try FunctionDeclSyntax("func ==(lhs: \(type), rhs: \(type)) -> Bool") {
                             if let lastBinding = variables.removeLast().bindings.first?.pattern {

Sources/VexilMacros/Utilities/SimpleVariables.swift

@@ -22,6 +22,29 @@ extension MemberBlockSyntax {
         }
     }
 
+    var storedVariables: [VariableDeclSyntax] {
+        variables.filter { variable in
+            // Only simple properties
+            guard variable.bindings.count == 1, let binding = variable.bindings.first else {
+                return false
+            }
+
+            // If it has no accessor block it's stored
+            guard let accessorBlock = binding.accessorBlock else {
+                return true
+            }
+
+            // If there is any kind of getter then its computed
+            switch accessorBlock.accessors {
+            case .getter:
+                return false
+
+            case let .accessors(accessors):
+                return accessors.allSatisfy { $0.accessorSpecifier.tokenKind != .keyword(.get) }
+            }
+        }
+    }
+
 }
 
 extension VariableDeclSyntax {

Tests/VexilMacroTests/EquatableFlagContainerMacroTests.swift

@@ -64,6 +64,19 @@ final class EquatableFlagContainerMacroTests: XCTestCase {
             struct TestFlags {
                 @Flag(default: false, description: "Some Flag")
                 var someFlag: Bool
+
+                var someComputedNotEquatableProperty: (any Error)? {
+                    nil
+                }
+
+                var someComputedPropertyWithAGetter: (any Error)? {
+                    get { fatalError() }
+                    set { fatalError() }
+                }
+
+                var otherStoredProperty: Int {
+                    didSet { fatalError() }
+                }
             }
             """,
             expandedSource: """
@@ -86,6 +99,19 @@ final class EquatableFlagContainerMacroTests: XCTestCase {
                     )
                 }
 
+                var someComputedNotEquatableProperty: (any Error)? {
+                    nil
+                }
+
+                var someComputedPropertyWithAGetter: (any Error)? {
+                    get { fatalError() }
+                    set { fatalError() }
+                }
+
+                var otherStoredProperty: Int {
+                    didSet { fatalError() }
+                }
+
                 fileprivate let _flagKeyPath: FlagKeyPath
 
                 fileprivate let _flagLookup: any FlagLookup
@@ -120,7 +146,8 @@ final class EquatableFlagContainerMacroTests: XCTestCase {
 
             extension TestFlags: Equatable {
                 static func ==(lhs: TestFlags, rhs: TestFlags) -> Bool {
-                    lhs.someFlag == rhs.someFlag
+                    lhs.someFlag == rhs.someFlag &&
+                    lhs.otherStoredProperty == rhs.otherStoredProperty
                 }
             }
             """,