Fix decoding OpenAPIDateWithoutTime (#17146)

* Fix decoding OpenAPIDateWithoutTime which in previous implementation only worked when used with CodableHelper, because it encoded to String, but tried to decode from Date afterwards

* update samples

* Update OpenAPIDateWithoutTime.mustache

* Update sample projects

---------

Co-authored-by: William Cheng <wing328hk@gmail.com>
Co-authored-by: Bruno Coelho <4brunu@users.noreply.github.com>
Co-authored-by: Bruno Coelho <4brunu@gmail.com>

Author: 3 people

modules/openapi-generator/src/main/resources/swift5/OpenAPIDateWithoutTime.mustache

@@ -23,11 +23,21 @@ import Foundation
         case wrappedDate
         case timezone
     }
+
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} enum DecodingError: Error {
+        case notADateString
+    }
 
     /// On decoding ISO8601 timezone is assumed
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} init(from decoder: Decoder) throws {
         let container = try decoder.singleValueContainer()
-        self.wrappedDate = try container.decode(Date.self)
+
+        let dateString = try container.decode(String.self)
+        guard let date = OpenISO8601DateFormatter.withoutTime.date(from: dateString) else {
+            throw DecodingError.notADateString
+        }
+        self.wrappedDate = date
+
         self.timezone = OpenISO8601DateFormatter.withoutTime.timeZone
     }
 
@@ -60,10 +70,14 @@ import Foundation
         return wrappedDate.addingTimeInterval(
             Double(timezone.secondsFromGMT(for: wrappedDate)))
     }
+
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static func == (lhs: Self, rhs: Self) -> Bool {
+        Calendar.current.compare(lhs.wrappedDate, to: rhs.wrappedDate, toGranularity: .day) == .orderedSame
+    }
 }
 
 extension OpenAPIDateWithoutTime: JSONEncodable {
     func encodeToJSON() -> Any {
         return OpenISO8601DateFormatter.withoutTime.string(from: self.normalizedWrappedDate())
     }
-}
+}

samples/client/petstore/swift5/alamofireLibrary/PetstoreClient/Classes/OpenAPIs/OpenAPIDateWithoutTime.swift

@@ -23,11 +23,21 @@ public struct OpenAPIDateWithoutTime: Codable, Hashable, Equatable {
         case wrappedDate
         case timezone
     }
+
+    public enum DecodingError: Error {
+        case notADateString
+    }
 
     /// On decoding ISO8601 timezone is assumed
     public init(from decoder: Decoder) throws {
         let container = try decoder.singleValueContainer()
-        self.wrappedDate = try container.decode(Date.self)
+
+        let dateString = try container.decode(String.self)
+        guard let date = OpenISO8601DateFormatter.withoutTime.date(from: dateString) else {
+            throw DecodingError.notADateString
+        }
+        self.wrappedDate = date
+
         self.timezone = OpenISO8601DateFormatter.withoutTime.timeZone
     }
 
@@ -60,10 +70,14 @@ public struct OpenAPIDateWithoutTime: Codable, Hashable, Equatable {
         return wrappedDate.addingTimeInterval(
             Double(timezone.secondsFromGMT(for: wrappedDate)))
     }
+
+    public static func == (lhs: Self, rhs: Self) -> Bool {
+        Calendar.current.compare(lhs.wrappedDate, to: rhs.wrappedDate, toGranularity: .day) == .orderedSame
+    }
 }
 
 extension OpenAPIDateWithoutTime: JSONEncodable {
     func encodeToJSON() -> Any {
         return OpenISO8601DateFormatter.withoutTime.string(from: self.normalizedWrappedDate())
     }
-}
+}

samples/client/petstore/swift5/alamofireLibrary/SwaggerClientTests/SwaggerClientTests/DateFormatTests.swift

@@ -111,4 +111,11 @@ class DateFormatTests: XCTestCase {
 		XCTAssert(jsonString == exampleJSONString, "Encoded JSON String: \(jsonString) should match: \(exampleJSONString)")
 	}
 
+    func testCodableOpenAPIDateWithoutTime() throws {
+        let sut = OpenAPIDateWithoutTime(wrappedDate: Date(timeIntervalSince1970: 0))
+        let encodedDate = try JSONEncoder().encode(sut)
+        let decodedDate = try JSONDecoder().decode(OpenAPIDateWithoutTime.self, from: encodedDate)
+
+        XCTAssert(sut == decodedDate, "Decoded date: \(decodedDate) should match initially given date: \(String(describing: sut))")
+    }
 }