Wraps a SwiftUI Text View in a VStack and offers a Button that toggles an expanded state by changing the maximum number of lines.

ExpandableText.swift

//
//  ExpandableText.swift
//
//  Created by TomQDRS on 06.08.21.
//

import SwiftUI

extension Text {
    
    func expandable() -> some View {
        return self.modifier(ExpandableText())
    }
}

struct ExpandableText: ViewModifier {
    
    @State private var isExpanded: Bool = false
    
    private var chevron: Image {
        isExpanded ? Image(systemName: "chevron.up") : Image(systemName: "chevron.down")
    }
    
    func body(content: Content) -> some View {
        
        VStack(alignment: .leading, spacing: 8) {
            
            content.lineLimit(isExpanded ? nil : 2)

            Button {
                withAnimation {
                    isExpanded.toggle()
                }
            } label: {
                HStack(spacing: 4) {
                    Text(isExpanded ? "show less" : "show more")
                    chevron
                }
            }
        }
    }
}