Add som units tests (split some code to made some part testable)

Tests/ResgenSwiftTests/Fonts/FontPlistGeneratorTests.swift

@@ -0,0 +1,35 @@
+//
+//  FontPlistGeneratorTests.swift
+//  
+//
+//  Created by Thibaut Schmitt on 05/09/2022.
+//
+
+import Foundation
+import XCTest
+
+@testable import ResgenSwift
+
+final class FontPlistGeneratorTests: XCTestCase {
+    func testGeneratedPlist() {
+        // Given
+        let fontNames: [FontName] = [
+            "CircularStd-Regular",
+            "CircularStd-Bold"
+        ]
+        
+        // When
+        let plistContent = FontPlistGenerator.generatePlistUIAppsFontContent(for: fontNames)
+        
+        // Expect
+        let expect = """
+        <key>UIAppFonts</key>
+            <array>
+                <string>CircularStd-Regular</string>
+                <string>CircularStd-Bold</string>
+            </array>
+        """
+        
+        XCTAssertEqual(plistContent.adaptForXCTest(), expect.adaptForXCTest())
+    }
+}