Improved FetchableMember single boolean support

Author: ABridoux

Sources/SafeFetching/Extensions/NSPredicate+Convenience.swift

@@ -22,4 +22,14 @@ extension NSPredicate {
         let predicate = predicate(SourceEntity.fetchableMembers)
         return predicate.nsValue
     }
+
+    /// Safely builds a predicate for a provided entity type.
+    public static func safe<SourceEntity: Fetchable, TargetEntity: Fetchable>(
+        on _: SourceEntity.Type,
+        _ fetchableMember: (SourceEntity.FetchableMembers) -> FetchableMember<TargetEntity, Bool>
+    ) -> NSPredicate {
+        let fetchableMember = fetchableMember(SourceEntity.fetchableMembers)
+        let predicate = Builders.Predicate<TargetEntity>(identifier: fetchableMember.identifier, operatorString: "==", value: true)
+        return predicate.nsValue
+    }
 }

Sources/SafeFetching/Predicate/Types/CompoundPredicate.swift

@@ -60,7 +60,7 @@ public func || <LE: NSManagedObject, RE: NSManagedObject>(
     )
 }
 
-// MARK: - KeyPath <-> Predicate
+// MARK: - KeyPath <-> FetchableMember
 
 public func && <LE: NSManagedObject, RE: NSManagedObject>(
     lhs: FetchableMember<LE, Bool>,
@@ -84,7 +84,7 @@ public func || <LE: NSManagedObject, RE: NSManagedObject>(
     )
 }
 
-// MARK: - Predicate <-> KeyPath
+// MARK: - Predicate <-> FetchableMember
 
 public func && <LE: NSManagedObject, RE: NSManagedObject>(
     lhs: Builders.Predicate<LE>,
@@ -93,7 +93,7 @@ public func && <LE: NSManagedObject, RE: NSManagedObject>(
     Builders.CompoundPredicate(
         joinOperator: .and,
         leftPredicate: lhs,
-        rightPredicate:  Builders.Predicate<RE>(identifier: rhs.identifier)
+        rightPredicate: Builders.Predicate<RE>(identifier: rhs.identifier)
     )
 }
 
@@ -104,6 +104,30 @@ public func || <LE: NSManagedObject, RE: NSManagedObject>(
     Builders.CompoundPredicate(
         joinOperator: .or,
         leftPredicate: lhs,
-        rightPredicate:  Builders.Predicate<RE>(identifier: rhs.identifier)
+        rightPredicate: Builders.Predicate<RE>(identifier: rhs.identifier)
+    )
+}
+
+// MARK: - FetchableMember <-> FetchableMember
+
+public func && <LE: NSManagedObject, RE: NSManagedObject>(
+    lhs: FetchableMember<LE, Bool>,
+    rhs: FetchableMember<RE, Bool>
+) -> Builders.CompoundPredicate<LE, RE> {
+    Builders.CompoundPredicate(
+        joinOperator: .and,
+        leftPredicate: Builders.Predicate<LE>(identifier: lhs.identifier),
+        rightPredicate: Builders.Predicate<RE>(identifier: rhs.identifier)
+    )
+}
+
+public func || <LE: NSManagedObject, RE: NSManagedObject>(
+    lhs: FetchableMember<LE, Bool>,
+    rhs: FetchableMember<RE, Bool>
+) -> Builders.CompoundPredicate<LE, RE> {
+    Builders.CompoundPredicate(
+        joinOperator: .or,
+        leftPredicate: Builders.Predicate<LE>(identifier: lhs.identifier),
+        rightPredicate: Builders.Predicate<RE>(identifier: rhs.identifier)
     )
 }

Tests/SafeFetchingTests/BooleanPredicateBuilderTests.swift

@@ -130,6 +130,20 @@ extension BooleanPredicates {
     }
 }
 
+// MARK: - NSPredicate
+
+extension BooleanPredicates {
+
+    @Test("NSPredicate.safe")
+    func nsPredicateSafe() {
+        var predicate = NSPredicate.safe(on: StubEntity.self) { $0.isAdmin }
+        #expect(predicate.predicateFormat == "isAdmin == 1")
+
+        predicate = NSPredicate.safe(on: StubEntity.self) { $0.stubRelationship.isDownloaded }
+        #expect(predicate.predicateFormat == "stubRelationship.isDownloaded == 1")
+    }
+}
+
 // MARK: - Helpers
 
 extension BooleanPredicates {
@@ -184,11 +198,13 @@ extension BooleanPredicates {
     final class StubEntityBis: NSManagedObject, Fetchable {
 
         @objc var property: String? = ""
+        @objc var isDownloaded: Bool = false
 
         static let fetchableMembers = FetchableMembers()
 
         struct FetchableMembers {
             let property = FetchableMember<StubEntityBis, String?>(identifier: "property")
+            let isDownloaded = FetchableMember<StubEntityBis, Bool>(identifier: "isDownloaded")
         }
     }
 }

Tests/SafeFetchingTests/CompoundPredicateBuilderTests.swift

@@ -74,6 +74,12 @@ extension CompoundPredicates {
     func orSingleBooleanLeft() {
         testNSFormat({ $0.name == "Toto" || $0.isDownloaded }, expecting: #"name == "Toto" OR isDownloaded == 1"#)
     }
+
+    @Test("Both Boolean FetchableMember")
+    func bothBooleanFetchableMember() {
+        testNSFormat({ $0.isDownloaded && $0.isDownloaded }, expecting: #"isDownloaded == 1 AND isDownloaded == 1"#)
+        testNSFormat({ $0.isDownloaded || $0.isDownloaded }, expecting: #"isDownloaded == 1 OR isDownloaded == 1"#)
+    }
 }
 
 // MARK: - Helpers