Fix mixed CDATA usage (#261)

Fixes #260

Author: johankool

Sources/XMLCoder/Decoder/XMLKeyedDecodingContainer.swift

@@ -275,9 +275,14 @@ extension XMLKeyedDecodingContainer {
         }
 
         // If we are looking at a coding key value intrinsic where the expected type is `String` and
-        // the value is empty, return `""`.
+        // the value is empty, return CDATA if present otherwise `""`.
         if strategy(key) != .attribute, elements.isEmpty, attributes.isEmpty, type == String.self, key.stringValue == "", let emptyString = "" as? T {
-            return emptyString
+            let cdata = container.withShared { keyedBox in
+                keyedBox.elements["#CDATA"].map {
+                    return ($0 as? KeyedBox)?.value ?? $0
+                }
+            }.first
+            return ((cdata as? StringBox)?.unboxed as? T) ?? emptyString
         }
 
         switch strategy(key) {

Tests/XMLCoderTests/CDATAMixedUsageTest.swift

@@ -0,0 +1,36 @@
+//
+//  CDATAMixedUsageTest.swift
+//  XMLCoderTests
+//
+//  Created by Johan Kool on 15/03/2023.
+//
+
+import XCTest
+import XMLCoder
+
+final class CDATAMixedUsageTest: XCTestCase {
+    private struct DataEntry: Codable, Equatable {
+        let value: String
+        enum CodingKeys: String, CodingKey {
+            case value = ""
+        }
+    }
+    
+    private struct Container: Codable, Equatable {
+        let data: [DataEntry]
+    }
+    
+    private let xml =
+        """
+        <container>
+           <data><![CDATA[lorem ipsum]]></data>
+           <data>bla bla</data>
+        </container>
+        """.data(using: .utf8)!
+    
+    func testXMLWithMixedCDATAUsage() throws {
+        let decoder = XMLDecoder()
+        let result = try decoder.decode(Container.self, from: xml)
+        XCTAssertEqual(result, Container(data: [.init(value: "lorem ipsum"), .init(value: "bla bla")]))
+    }
+}

XMLCoder.xcodeproj/project.pbxproj

@@ -33,6 +33,7 @@
 		B5647C4824897589001F6507 /* Element.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5647C4724897589001F6507 /* Element.swift */; };
 		B5E67535238B4960006C8548 /* IntOrString.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5E67534238B4960006C8548 /* IntOrString.swift */; };
 		B5F74472233F74E400BBDB15 /* RootLevelAttributeTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5F74471233F74E400BBDB15 /* RootLevelAttributeTest.swift */; };
+		C7D23FB529C23A5F00CAD394 /* CDATAMixedUsageTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = C7D23FB429C23A5F00CAD394 /* CDATAMixedUsageTest.swift */; };
 		D11E094623491BCE00C24DCB /* DoubleBox.swift in Sources */ = {isa = PBXBuildFile; fileRef = D11E094523491BCE00C24DCB /* DoubleBox.swift */; };
 		D11E094A234924C500C24DCB /* ValueBox.swift in Sources */ = {isa = PBXBuildFile; fileRef = D11E0949234924C500C24DCB /* ValueBox.swift */; };
 		D18FBFB82348FAE500FA4F65 /* EscapedCharactersTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = D18FBFB72348FAE500FA4F65 /* EscapedCharactersTest.swift */; };
@@ -184,6 +185,7 @@
 		B5647C4724897589001F6507 /* Element.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Element.swift; sourceTree = "<group>"; };
 		B5E67534238B4960006C8548 /* IntOrString.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = IntOrString.swift; sourceTree = "<group>"; };
 		B5F74471233F74E400BBDB15 /* RootLevelAttributeTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RootLevelAttributeTest.swift; sourceTree = "<group>"; };
+		C7D23FB429C23A5F00CAD394 /* CDATAMixedUsageTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CDATAMixedUsageTest.swift; sourceTree = "<group>"; };
 		D11E094523491BCE00C24DCB /* DoubleBox.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DoubleBox.swift; sourceTree = "<group>"; };
 		D11E0949234924C500C24DCB /* ValueBox.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ValueBox.swift; sourceTree = "<group>"; };
 		D18FBFB72348FAE500FA4F65 /* EscapedCharactersTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EscapedCharactersTest.swift; sourceTree = "<group>"; };
@@ -500,6 +502,7 @@
 				D1A1838724842D710058E66D /* AdvancedFeatures */,
 				D1A1839324842D710058E66D /* EndToEnd */,
 				D1A1838324842C920058E66D /* CDATATest.swift */,
+				C7D23FB429C23A5F00CAD394 /* CDATAMixedUsageTest.swift */,
 				D1A1838024842C7D0058E66D /* PrettyPrintTest.swift */,
 				OBJ_68 /* BenchmarkTests.swift */,
 				OBJ_88 /* ClassTests.swift */,
@@ -833,6 +836,7 @@
 				D1A183C324842DE80058E66D /* AttributedIntrinsicTest.swift in Sources */,
 				D1A183C424842DE80058E66D /* MixedChoiceAndNonChoiceTests.swift in Sources */,
 				OBJ_256 /* URLTests.swift in Sources */,
+				C7D23FB529C23A5F00CAD394 /* CDATAMixedUsageTest.swift in Sources */,
 				OBJ_257 /* UnkeyedIntTests.swift in Sources */,
 				D1A183B824842DE20058E66D /* CDTest.swift in Sources */,
 				OBJ_258 /* UnkeyedTests.swift in Sources */,