https://twitter.com/krzyzanowskim/status/1478866553122824192

SwiftUITextFieldEditingCase.swift

import SwiftUI
import PlaygroundSupport

struct TestView: View {
    @State var text: String = ""
    @State var dummy: String = "dummy"
    @State var showTextField1: Bool = true
    @State var showTextField2: Bool = true

    var body: some View {
        VStack {

            if showTextField1 {
                TextField(
                    "",
                    text: $text,
                    onEditingChanged: { editing in
                        print("editing \(editing)") // <- not called on textfield hide
                    },
                    onCommit: {
                        print("commit") // <- not called on textfield hide
                    }
                )
            }

            Button("toggle") {
                showTextField1.toggle()
            }

            if showTextField2 {
                MyTextFieldView()
            }

            Button("toggle") {
                showTextField2.toggle()
            }
        }
        .frame(width: 100)
    }
}

struct MyTextFieldView: NSViewRepresentable {
    func makeNSView(context: Context) -> NSTextField {
        let field = MyTextField()
        return field
    }

    func updateNSView(_ nsView: NSTextField, context: Context) {

    }
}

class MyTextField: NSTextField {

    override func textDidEndEditing(_ notification: Notification) {
        print("textDidEndEditing") // <- called on hide textfield
        super.textDidEndEditing(notification)
    }
}

PlaygroundPage.current.setLiveView(TestView())