chibuezefelix

import 'package:flutter/material.dart';
import 'package:expansion_tile_card/expansion_tile_card.dart';
import 'package:gitexpo/single-card.dart';
import 'package:gitexpo/utils/styles.dart';

void main() {
  runApp(GitExpo());
}

chibuezefelix

import 'dart:io';
import 'dart:ui' as ui;
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/services.dart';
import 'package:logger/logger.dart';
import 'package:path_provider/path_provider.dart';
import 'package:permission_handler/permission_handler.dart';

chibuezefelix

fun Modifier.conditional(
    condition: Boolean,
    ifTrue: Modifier.() -> Modifier,
    ifFalse: (Modifier.() -> Modifier)? = null,
): Modifier {
    return if (condition) {
        then(ifTrue(Modifier))
    } else if (ifFalse != null) {
        then(ifFalse(Modifier))
    } else {

chibuezefelix

The structural goal is that the raw two digit string exists in exactly one place in your codebase, and everything downstream works with a typed value. String comparison of ECI codes scattered across services is how the brand confusion described above gets into production.
Start with the two enums.
package com.example.payments.threeds;

public enum CardBrand {
    VISA,
    MASTERCARD,
    AMERICAN_EXPRESS,
    DISCOVER,