feat(ad-hoc): card formatting tests (#147)

Add CardExpirationFormatter and CardNumberFormatter tests.

Sources/ProcessOut/Sources/Core/Formatters/CardExpiration/CardExpirationFormatter.swift

@@ -22,15 +22,18 @@ final class CardExpirationFormatter: Formatter {
     /// Returns formatted version of given expiration string.
     func string(from string: String) -> String {
         let expiration = self.expiration(from: string)
-        guard !expiration.month.isEmpty || !expiration.year.isEmpty else {
+        guard !expiration.month.isEmpty else {
             return ""
         }
         return formatted(month: expiration.month, year: expiration.year)
     }
 
     func expirationMonth(from string: String) -> Int? {
         let monthDescription = expiration(from: string).month
-        return Int(monthDescription)
+        guard let month = Int(monthDescription), month > 0, month <= 12 else {
+            return nil
+        }
+        return month
     }
 
     func expirationYear(from string: String) -> Int? {
@@ -104,11 +107,8 @@ final class CardExpirationFormatter: Formatter {
     }
 
     private func formatted(month: String, forcePadding: Bool) -> String {
-        if month.isEmpty {
-            return ""
-        }
         guard let monthValue = Int(month) else {
-            assertionFailure("Month should be valid integer or empty.")
+            assertionFailure("Month should be valid integer.")
             return month
         }
         guard monthValue != 0 else {

Sources/ProcessOut/Sources/Core/Formatters/CardNumber/CardNumberFormatter.swift

@@ -16,10 +16,7 @@ final class CardNumberFormatter: Formatter {
                 return formattedNumber
             }
         }
-        if let formattedNumber = attemptToFormat(cardNumber: normalizedNumber, pattern: Constants.defaultPattern) {
-            return formattedNumber
-        }
-        return partialNumber
+        return attemptToFormat(cardNumber: normalizedNumber, pattern: Constants.defaultPattern) ?? partialNumber
     }
 
     func normalized(number: String) -> String {

Tests/ProcessOutTests/Sources/Unit/Core/Formatters/CardExpiration/CardExpirationFormatterTests.swift

@@ -0,0 +1,109 @@
+//
+//  CardExpirationFormatterTests.swift
+//  ProcessOut
+//
+//  Created by Andrii Vysotskyi on 21.07.2023.
+//
+
+import XCTest
+@testable import ProcessOut
+
+final class CardExpirationFormatterTests: XCTestCase {
+
+    override func setUp() {
+        super.setUp()
+        sut = CardExpirationFormatter()
+    }
+
+    func test_string() {
+        // When
+        let formatted = sut.string(from: "1230")
+
+        // Then
+        XCTAssertEqual(formatted, "12 / 30")
+    }
+
+    func test_string_whenStringHasNoDigits_returnsEmptyString() {
+        // When
+        let formatted = sut.string(from: "a")
+
+        // Then
+        XCTAssertEqual(formatted, "")
+    }
+
+    func test_string_whenStringIsPrefixedWithZeros_keepsZingleZero() {
+        // When
+        let formatted = sut.string(from: "001")
+
+        // Then
+        XCTAssertEqual(formatted, "01 / ")
+    }
+
+    func test_string_whenStringHasOnlyZeros_returnsZero() {
+        // When
+        let formatted = sut.string(from: "000")
+
+        // Then
+        XCTAssertEqual(formatted, "0")
+    }
+
+    func test_string_returnsPaddedMonth() {
+        // Given
+        let strings = (2...9).map(\.description)
+
+        // When
+        let formatted = strings.map(sut.string(from:))
+
+        // Then
+        let allSatisfy = formatted.allSatisfy { $0.first == "0" }
+        XCTAssertTrue(allSatisfy)
+    }
+
+    func test_string_whenMonthIsIncomplete_returnsIt() {
+        // When
+        let formatted = sut.string(from: "1")
+
+        // Then
+        XCTAssertEqual(formatted, "1")
+    }
+
+    // MARK: - Expiration Month
+
+    func test_expirationMonth_returnsValue() {
+        // When
+        let month = sut.expirationMonth(from: "01")
+
+        // Then
+        XCTAssertEqual(month, 1)
+    }
+
+    func test_expirationMonth_whenMonthIsInvalid_returnsNil() {
+        // When
+        let month = sut.expirationMonth(from: "0")
+
+        // Then
+        XCTAssertEqual(month, nil)
+    }
+
+    // MARK: - Expiration Year
+
+    func test_expirationYear_returnsValue() {
+        // When
+        let year = sut.expirationYear(from: "01/1")
+
+        // Then
+        XCTAssertEqual(year, 1)
+    }
+
+    func test_expirationYear_whenYearComponentIsNotSet_returnsNil() {
+        // When
+        let year = sut.expirationYear(from: "01/")
+
+        // Then
+        XCTAssertEqual(year, nil)
+    }
+
+    // MARK: - Private Properties
+
+    private var sut: CardExpirationFormatter!
+}

Tests/ProcessOutTests/Sources/Unit/Core/Formatters/CardNumber/CardNumberFormatterTests.swift

@@ -17,18 +17,42 @@ final class CardNumberFormatterTests: XCTestCase {
 
     func test_normalized_retainsDigits() {
         // When
-        let normalizedNumber = sut.normalized(number: "+1#")
+        let normalized = sut.normalized(number: "+1#")
 
         // Then
-        XCTAssertEqual(normalizedNumber, "1")
+        XCTAssertEqual(normalized, "1")
     }
 
-    func test_string() {
+    func test_string_whenHasNoMatchingLeading_fallsBackToDefaultPattern() {
         // When
-        let formattedNumber = sut.string(from: "621")
+        let formatted = sut.string(from: "99999")
 
         // Then
-        XCTAssertEqual(formattedNumber, "621")
+        XCTAssertEqual(formatted, "9999 9")
+    }
+
+    func test_string_returnsFormattedNumber() {
+        // When
+        let formatted = sut.string(from: "123456789123456")
+
+        // Then
+        XCTAssertEqual(formatted, "1234 56789 123456")
+    }
+
+    func test_string_whenEmpty_returnsEmptyString() {
+        // When
+        let formatted = sut.string(from: "")
+
+        // Then
+        XCTAssertEqual(formatted, "")
+    }
+
+    func test_string_whenExceedsMaxLength_returnsValueWithoutExcessiveSuffix() {
+        // When
+        let formatted = sut.string(from: "12345678912345678910")
+
+        // Then
+        XCTAssertEqual(formatted, "1234 5678 9123 4567 891")
     }
 
     // MARK: - Private Properties