writing-app-group.swift

// Create from App Group ❌
// let appGroupID = "group.com.christianselig.testing"
// let containerURL = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: appGroupID)!
// let directoryURL = containerURL.appending(path: "testfolder")

// Create from documents directory ✅
let containerURL = try! FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false)
let directoryURL = containerURL.appending(path: "testfolder")

if !FileManager.default.fileExists(atPath: directoryURL.path) {
    try! FileManager.default.createDirectory(at: directoryURL, withIntermediateDirectories: true, attributes: nil)
}

let fileURL = directoryURL.appending(path: "tropy", directoryHint: .notDirectory)
try! "hihowareyou".write(to: fileURL, atomically: true, encoding: .utf8)

// In BOTH cases it even writes the file correctly and can be read! 🫨
print("Contents: \(try! String(contentsOf: fileURL, encoding: .utf8))")