review comments

Author: rnro

Sources/OpenAPIRuntime/Base/Base64EncodedData.swift

@@ -15,24 +15,35 @@
 import Foundation
 
 public struct Base64EncodedData: Sendable, Codable, Hashable {
-    var data: Foundation.Data // or [UInt8] or ArraySlice<UInt8>
+    var data: ArraySlice<UInt8>
 
-    public init(data: Foundation.Data) {
+    public init(data: ArraySlice<UInt8>) {
         self.data = data
     }
 
     public init(from decoder: any Decoder) throws {
         let container = try decoder.singleValueContainer()
         let base64EncodedString = try container.decode(String.self)
-        guard let data = Data(base64Encoded: base64EncodedString) else {
+
+        // permissive decoding
+        let options = Data.Base64DecodingOptions.ignoreUnknownCharacters
+
+        guard let data = Data(base64Encoded: base64EncodedString, options: options) else {
             throw RuntimeError.invalidBase64String(base64EncodedString)
         }
-        self.init(data: data)
+        self.init(data: ArraySlice(data))
     }
 
     public func encode(to encoder: any Encoder) throws {
         var container = encoder.singleValueContainer()
-        let base64String = data.base64EncodedString()
+
+        // https://datatracker.ietf.org/doc/html/rfc4648#section-3.1
+        // "Implementations MUST NOT add line feeds to base-encoded data unless
+        // the specification referring to this document explicitly directs base
+        // encoders to add line feeds after a specific number of characters."
+        let options = Data.Base64EncodingOptions()
+
+        let base64String = Data(data).base64EncodedString(options: options)
         try container.encode(base64String)
     }
 }

Tests/OpenAPIRuntimeTests/Base/Test_OpenAPIValue.swift

@@ -267,9 +267,27 @@ final class Test_OpenAPIValue: Test_Runtime {
         XCTAssertEqual(nestedValue, 2)
     }
 
-    func testEncodingDecodingRoundTrip_base64_success() throws {
-        print(String(data: testStructData.base64EncodedData(), encoding: .utf8)!.utf8)
-        let encodedData = Base64EncodedData(data: testStructData)
+    func testEncoding_base64_success() throws {
+        let encodedData = Base64EncodedData(data: ArraySlice(testStructData))
+
+        let JSONEncoded = try JSONEncoder().encode(encodedData)
+        XCTAssertEqual(String(data: JSONEncoded, encoding: .utf8)!, testStructBase64EncodedString)
+    }
+
+    func testDecoding_base64_success() throws {
+        let encodedData = Base64EncodedData(data: ArraySlice(testStructData))
+
+        // `testStructBase64EncodedString` quoted and base64-encoded again
+        let JSONEncoded = Data(base64Encoded: "ImV5SnVZVzFsSWpvaVJteDFabVo2SW4wPSI=")!
+
+        XCTAssertEqual(
+            try JSONDecoder().decode(Base64EncodedData.self, from: JSONEncoded),
+            encodedData
+        )
+    }
+
+    func testEncodingDecodingRoundtrip_base64_success() throws {
+        let encodedData = Base64EncodedData(data: ArraySlice(testStructData))
         XCTAssertEqual(
             try JSONDecoder().decode(Base64EncodedData.self, from: JSONEncoder().encode(encodedData)),
             encodedData

Tests/OpenAPIRuntimeTests/Test_Runtime.swift

@@ -107,6 +107,10 @@ class Test_Runtime: XCTestCase {
         "age=3&name=Rover%21&type=Golden+Retriever"
     }
 
+    var testStructBase64EncodedString: String {
+        #""eyJuYW1lIjoiRmx1ZmZ6In0=""# // {"name":"Fluffz"}
+    }
+
     var testEnum: TestHabitat {
         .water
     }