fix: DPS-292 fixes externalPayerInfo on Paypal (#849)

* Mirror externalPayerId to external_payer_id in PayPal instrument

* Also mirror firsName and lastName

* Add constructor for tests

* Added unit tests for mirrored encode/decode

Sources/PrimerSDK/Classes/Data Models/PayPal.swift

@@ -75,7 +75,87 @@ extension Response.Body.Tokenization {
 
         // swiftlint:disable:next nesting
         public struct ExternalPayerInfo: Codable {
-            public var externalPayerId, email, firstName, lastName: String?
+            public var externalPayerId, externalPayerIdSnakeCase,
+                       email,
+                       firstName, firstNameSnakeCase,
+                       lastName, lastNameSnakeCase: String?
+
+            public init(externalPayerId: String,
+                        externalPayerIdSnakeCase: String? = nil,
+                        email: String,
+                        firstName: String?,
+                        firstNameSnakeCase: String? = nil,
+                        lastName: String,
+                        lastNameSnakeCase: String? = nil) {
+                self.externalPayerId = externalPayerId
+                self.externalPayerIdSnakeCase = externalPayerIdSnakeCase ?? externalPayerId
+                self.email = email
+                self.firstName = firstName
+                self.firstNameSnakeCase = firstNameSnakeCase ?? firstName
+                self.lastName = lastName
+                self.lastNameSnakeCase = lastNameSnakeCase ?? lastName
+            }
+
+            public init(from decoder: Decoder) throws {
+                let container: KeyedDecodingContainer<Response.Body.Tokenization.PayPal.ExternalPayerInfo.CodingKeys> =
+                try decoder.container(keyedBy: Response.Body.Tokenization.PayPal.ExternalPayerInfo.CodingKeys.self)
+
+                self.externalPayerId = try container.decodeIfPresent(
+                    String.self,
+                    forKey: Response.Body.Tokenization.PayPal.ExternalPayerInfo.CodingKeys.externalPayerId)
+
+                self.externalPayerIdSnakeCase = try container.decodeIfPresent(
+                    String.self,
+                    forKey: Response.Body.Tokenization.PayPal.ExternalPayerInfo.CodingKeys.externalPayerIdSnakeCase)
+
+                self.email = try container.decodeIfPresent(
+                    String.self,
+                    forKey: Response.Body.Tokenization.PayPal.ExternalPayerInfo.CodingKeys.email)
+
+                self.firstName = try container.decodeIfPresent(
+                    String.self,
+                    forKey: Response.Body.Tokenization.PayPal.ExternalPayerInfo.CodingKeys.firstName)
+
+                self.firstNameSnakeCase = try container.decodeIfPresent(
+                    String.self,
+                    forKey: Response.Body.Tokenization.PayPal.ExternalPayerInfo.CodingKeys.firstNameSnakeCase)
+
+                self.lastName = try container.decodeIfPresent(
+                    String.self,
+                    forKey: Response.Body.Tokenization.PayPal.ExternalPayerInfo.CodingKeys.lastName)
+
+                self.lastNameSnakeCase = try container.decodeIfPresent(
+                    String.self,
+                    forKey: Response.Body.Tokenization.PayPal.ExternalPayerInfo.CodingKeys.lastNameSnakeCase)
+
+                // This logic ensures we mirror externalPayerId to external_payer_id and vice versa
+                if self.externalPayerId == nil && self.externalPayerIdSnakeCase != nil {
+                    self.externalPayerId = self.externalPayerIdSnakeCase
+                } else if self.externalPayerIdSnakeCase == nil && self.externalPayerId != nil {
+                    self.externalPayerIdSnakeCase = self.externalPayerId
+                }
+
+                if firstName == nil && firstNameSnakeCase != nil {
+                    firstName = firstNameSnakeCase
+                } else if firstNameSnakeCase == nil && firstName != nil {
+                    firstNameSnakeCase = firstName
+                }
+
+                if lastName == nil && lastNameSnakeCase != nil {
+                    lastName = lastNameSnakeCase
+                } else if lastNameSnakeCase == nil && lastName != nil {
+                    lastNameSnakeCase = lastName
+                }
+            }
+
+            // swiftlint:disable:next nesting
+            enum CodingKeys: String, CodingKey {
+                case externalPayerId
+                case externalPayerIdSnakeCase = "external_payer_id"
+                case firstNameSnakeCase = "first_name"
+                case lastNameSnakeCase = "last_name"
+                case email, firstName, lastName
+            }
         }
     }
 }

Tests/Unit Tests/Data Models/PayPalResposeTests.swift

@@ -0,0 +1,106 @@
+//
+//  PayPalResposeTests.swift
+//  Debug App SPM
+//
+//  Created by Niall Quinn on 04/05/24.
+//  Copyright © 2024 Primer API Ltd. All rights reserved.
+//
+
+import XCTest
+@testable import PrimerSDK
+
+final class PayPalResposeTests: XCTestCase {
+
+    private typealias PayPalResponse = Response.Body.Tokenization.PayPal
+
+    func test_externalPayerInfo_snakecase() async {
+        let JSON_snake_case = """
+    {
+        "external_payer_id": "external-id",
+        "first_name": "John",
+        "last_name": "Doe",
+        "email": "[email protected]"
+    }
+    """
+
+        guard let data = JSON_snake_case.data(using: .utf8) else {
+            XCTFail()
+            return
+        }
+        do {
+            let decoder = JSONDecoder()
+            let decoded: PayPalResponse.ExternalPayerInfo = try decoder.decode(PayPalResponse.ExternalPayerInfo.self, from: data)
+
+            XCTAssertEqual(decoded.externalPayerId, "external-id")
+            XCTAssertEqual(decoded.externalPayerId, decoded.externalPayerIdSnakeCase)
+
+            XCTAssertEqual(decoded.firstName, "John")
+            XCTAssertEqual(decoded.firstName, decoded.firstNameSnakeCase)
+
+            XCTAssertEqual(decoded.lastName, "Doe")
+            XCTAssertEqual(decoded.lastName, decoded.lastNameSnakeCase)
+        } catch {
+            XCTFail()
+        }
+    }
+
+    func test_externalPayerInfo_camelcase() async {
+        let JSON_camelCase = """
+    {
+        "externalPayerId": "external-id",
+        "firstName": "John",
+        "lastName": "Doe",
+        "email": "[email protected]"
+    }
+    """
+
+        guard let data = JSON_camelCase.data(using: .utf8) else {
+            XCTFail()
+            return
+        }
+        do {
+            let decoder = JSONDecoder()
+            let decoded: PayPalResponse.ExternalPayerInfo = try decoder.decode(PayPalResponse.ExternalPayerInfo.self, from: data)
+
+            XCTAssertEqual(decoded.externalPayerId, "external-id")
+            XCTAssertEqual(decoded.externalPayerId, decoded.externalPayerIdSnakeCase)
+
+            XCTAssertEqual(decoded.firstName, "John")
+            XCTAssertEqual(decoded.firstName, decoded.firstNameSnakeCase)
+
+            XCTAssertEqual(decoded.lastName, "Doe")
+            XCTAssertEqual(decoded.lastName, decoded.lastNameSnakeCase)
+        } catch {
+            XCTFail()
+        }
+    }
+
+    func test_jsonEncoding() async {
+        let payerInfo = PayPalResponse.ExternalPayerInfo(externalPayerId: "external-id",
+                                                         email: "[email protected]",
+                                                         firstName: "John",
+                                                         lastName: "Doe")
+
+        do {
+            let encoder = JSONEncoder()
+            let encoded = try encoder.encode(payerInfo)
+            guard let string = String(data: encoded, encoding: .utf8) else {
+                XCTFail()
+                return
+            }
+
+            XCTAssertTrue(string.contains("\"externalPayerId\":\"external-id\""))
+            XCTAssertTrue(string.contains("\"external_payer_id\":\"external-id\""))
+
+            XCTAssertTrue(string.contains("\"firstName\":\"John\""))
+            XCTAssertTrue(string.contains("\"first_name\":\"John\""))
+
+            XCTAssertTrue(string.contains("\"lastName\":\"Doe\""))
+            XCTAssertTrue(string.contains("\"last_name\":\"Doe\""))
+
+            XCTAssertTrue(string.contains("\"email\":\"[email protected]\""))
+        } catch {
+            XCTFail()
+        }
+    }
+}