Failable conversion

Author: tevelee

Sources/AsyncHTTP/Utils/Converted.swift

@@ -6,11 +6,11 @@ public protocol ConversionStrategy {
 }
 
 public protocol DecoderStrategy: ConversionStrategy {
-    static func decode(_ value: RawValue) -> ConvertedValue
+    static func decode(_ value: RawValue) throws -> ConvertedValue
 }
 
 public protocol EncoderStrategy: ConversionStrategy {
-    static func encode(_ value: ConvertedValue) -> RawValue
+    static func encode(_ value: ConvertedValue) throws -> RawValue
 }
 
 public typealias TwoWayConversionStrategy = EncoderStrategy & DecoderStrategy
@@ -31,14 +31,14 @@ extension Converted: Decodable where Converter.RawValue: Decodable, Converter: D
     public init(from decoder: Decoder) throws {
         let container = try decoder.singleValueContainer()
         let rawValue = try container.decode(Converter.RawValue.self)
-        let decodedValue = Converter.decode(rawValue)
+        let decodedValue = try Converter.decode(rawValue)
         self.init(wrappedValue: decodedValue)
     }
 }
 
 extension Converted: Encodable where Converter.RawValue: Encodable, Converter: EncoderStrategy {
     public func encode(to encoder: Encoder) throws {
-        let rawValue = Converter.encode(wrappedValue)
+        let rawValue = try Converter.encode(wrappedValue)
         try rawValue.encode(to: encoder)
     }
 }
@@ -49,14 +49,14 @@ extension Optional: ConversionStrategy where Wrapped: ConversionStrategy {
 }
 
 extension Optional: EncoderStrategy where Wrapped: EncoderStrategy {
-    public static func encode(_ value: Wrapped.ConvertedValue?) -> Wrapped.RawValue? {
-        value.map(Wrapped.encode)
+    public static func encode(_ value: Wrapped.ConvertedValue?) throws -> Wrapped.RawValue? {
+        try value.map(Wrapped.encode)
     }
 }
 
 extension Optional: DecoderStrategy where Wrapped: DecoderStrategy {
-    public static func decode(_ value: Wrapped.RawValue?) -> Wrapped.ConvertedValue? {
-        value.map(Wrapped.decode)
+    public static func decode(_ value: Wrapped.RawValue?) throws -> Wrapped.ConvertedValue? {
+        try value.map(Wrapped.decode)
     }
 }
 

Tests/AsyncHTTPTests/ConvertedTests.swift

@@ -82,7 +82,12 @@ private struct ISO8601: TwoWayConversionStrategy {
         formatter.string(from: value)
     }
 
-    static func decode(_ value: String) -> Date {
-        formatter.date(from: value)!
+    static func decode(_ value: String) throws -> Date {
+        guard let date = formatter.date(from: value) else {
+            throw ConversionError()
+        }
+        return date
     }
+
+    struct ConversionError: Error {}
 }

Tests/AsyncHTTPTests/HTTPFormatterTests.swift

@@ -20,7 +20,7 @@ final class HTTPFormatterTests: XCTestCase {
         // Given
         let request = try HTTPRequest(url: URL(string: "https://google.com")!)!.configured { request in
             request[header: .userAgent] = "Safari"
-            request.body = try .json(["a": "b", "c": 1])
+            request.body = try .json(["a": "b", "c": 1], options: [.sortedKeys, .prettyPrinted])
         }
 
         // When
@@ -32,7 +32,10 @@ final class HTTPFormatterTests: XCTestCase {
         Content-Type: application/json; charset="utf-8"
         User-Agent: Safari
 
-        {"a":"b","c":1}
+        {
+          "a" : "b",
+          "c" : 1
+        }
         """#)
     }