Add Attribute+Debug support (#169)

Author: Kyle-Ye

Sources/OpenGraphShims/Attribute+Debug.swift

@@ -0,0 +1,91 @@
+//
+//  Attribute+Debug.swift
+//  OpenGraphShims
+
+#if canImport(Darwin) && DEBUG // Compiler crash for Darwin + release and non-Darwin build
+
+// Use 4 spaces instead of \t for bettern test case expect
+private let tab = "    "
+
+extension Attribute: Swift.CustomDebugStringConvertible {
+    public var debugDescription: String {
+        _debugDescription(indent: 0)
+    }
+    
+    func _debugDescription(indent: Int) -> String {
+        let tabs = String(repeating: tab, count: indent)
+        return #"""
+        \#(tabs)Attribute<\#(Value.self)> {
+        \#(identifier._debugDescription(indent: indent + 1))
+        \#(tabs)}
+        """#
+    }
+}
+
+extension AnyAttribute: Swift.CustomDebugStringConvertible {
+    public var debugDescription: String {
+        _debugDescription(indent: 0)
+    }
+    
+    func _debugDescription(indent: Int) -> String {
+        let tabs = String(repeating: tab, count: indent)
+
+        guard self != .nil else {
+            return "\(tabs)AnyAttribute.nil"
+        }
+        
+        var description = #"""
+        \#(tabs)rawValue: \#(rawValue)
+        \#(tabs)graph: \#(graph)
+        """#
+        
+        if rawValue % 2 == 0 { // direct
+            description.append("\n\(tabs)(direct attribute)")
+
+            let valueType = valueType
+            description.append("\n\(tabs)valueType: \(valueType)")
+
+            var value: Any!
+            func project1<T>(type: T.Type) {
+                value = unsafeCast(to: type).value
+            }
+            _openExistential(valueType, do: project1)
+            description.append("\n\(tabs)value: \(value!)")
+
+            let bodyType = _bodyType
+            description.append("\n\(tabs)bodyType: \(bodyType)")
+
+            var bodyValue: Any!
+            func project2<T>(type: T.Type) {
+                bodyValue = _bodyPointer.assumingMemoryBound(to: type).pointee
+            }
+            _openExistential(bodyType, do: project2)
+            
+            let bodyValueDescription = _formatBodyValue(bodyValue!, indent: indent)
+            description.append("\n\(tabs)bodyValue:\n\(bodyValueDescription)")
+
+        } else { // indirect
+            description.append("\n\(tabs)(indirect attribute)")
+            description.append("\n\(tabs)source attribute:")
+            description.append("\n\(source._debugDescription(indent: indent + 1))")
+        }
+        return description
+    }
+    
+    private func _formatBodyValue(_ bodyValue: Any, indent: Int) -> String {
+        let bodyValueString = String(describing: bodyValue)
+        let nextTabs = String(repeating: tab, count: indent + 1)
+
+        // Check if the body value contains attributes
+        if bodyValueString.contains("Attribute<") {
+            // Split lines and add proper indentation
+            let lines = bodyValueString.components(separatedBy: .newlines)
+            return lines.enumerated().map { index, line in
+                return "\(nextTabs)\(line)"
+            }.joined(separator: "\n")
+        }
+        
+        return "\(nextTabs)\(bodyValueString)"
+    }
+}
+#endif

Tests/OpenGraphShimsTests/Attribute+DebugTests.swift

@@ -0,0 +1,53 @@
+//
+//  Attribute+DebugTests.swift
+//  OpenGraphShimsTests
+
+#if canImport(Darwin) && DEBUG
+
+import Testing
+import OpenGraphShims
+
+@MainActor
+@Suite(.disabled(if: !attributeGraphEnabled, "Subgraph is not implemented on OG"), .graphScope)
+struct Attribute_DebugTests {
+    @Test
+    func directAttribute() {
+        let attribute = Attribute(value: 3)
+
+        #expect(attribute.debugDescription == #"""
+        Attribute<Int> {
+            rawValue: \#(attribute.identifier.rawValue)
+            graph: \#(attribute.graph)
+            (direct attribute)
+            valueType: Int
+            value: 3
+            bodyType: External<Int>
+            bodyValue:
+                Int
+        }
+        """#)
+    }
+
+    @Test
+    func indirectAttribute() {
+        let tuple = Attribute(value: Tuple(first: 1, second: "2"))
+        let second = tuple[keyPath: \.second]
+        #expect(second.debugDescription == #"""
+        Attribute<String> {
+            rawValue: \#(second.identifier.rawValue)
+            graph: \#(second.graph)
+            (indirect attribute)
+            source attribute:
+                rawValue: \#(tuple.identifier.rawValue)
+                graph: \#(tuple.graph)
+                (direct attribute)
+                valueType: Tuple<Int, String>
+                value: Tuple<Int, String>(first: 1, second: "2")
+                bodyType: External<Tuple<Int, String>>
+                bodyValue:
+                    Tuple<Int, String>
+        }
+        """#)
+    }
+}
+#endif