fix: Modify or create .gitignore files (#9)

Author: jcesarmobile

Sources/cap2spm.swift

@@ -53,6 +53,7 @@ struct Cap2SPM: ParsableCommand {
         try modifySwiftFile(at: swiftFileURL, plugin: capPlugin)
         try generatePackageSwiftFile(at: podspecFileURL, plugin: capPlugin)
         try modifyPodspec(at: podspecFileURL)
+        try modifyGitignores(with: capacitorPluginPackage)
 
         var fileList = [mFileURL, hFileURL]
         if shouldBackup {
@@ -116,6 +117,31 @@ struct Cap2SPM: ParsableCommand {
         try podspecText.write(to: fileURL, atomically: true, encoding: .utf8)
     }
 
+    private func modifyGitignores(with package: CapacitorPluginPackage) throws {
+        let baseEntries = ["/Packages", "xcuserdata/" ,"DerivedData/", ".swiftpm/configuration/registries.json", ".swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata", ".netrc"]
+        var rootEntries = ["Pods", "Podfile.lock", "Package.resolved", "Build", "xcuserdata", "/.build"]
+        rootEntries.append(contentsOf: baseEntries)
+        var iosEntries = [".DS_Store", ".build"]
+        iosEntries.append(contentsOf: baseEntries)
+        let rootGitignore = package.basePathURL.appending(path: ".gitignore")
+        let iOSGitignore = package.iosSrcDirectoryURL.appending(path: ".gitignore")
+        try modifyGitignore(at: rootGitignore, with: rootEntries)
+        try modifyGitignore(at: iOSGitignore, with: iosEntries)
+    }
+
+    private func modifyGitignore(at fileURL: URL, with content: [String]) throws {
+        var gitignoreText = ""
+        if FileManager.default.fileExists(atPath: fileURL.path()) {
+            gitignoreText = try String(contentsOf: fileURL, encoding: .utf8)
+        }
+        content.forEach {
+            if !gitignoreText.contains($0) {
+                gitignoreText.append("\n\($0)")
+            }
+        }
+        try gitignoreText.write(to: fileURL, atomically: true, encoding: .utf8)
+    }
+
     private func moveItemCreatingIntermediaryDirectories(at: URL, to: URL) throws {
         print("Moving \(at.path()) to \(to.path())...")
         let parentPath = to.deletingLastPathComponent()