How to Resolve Dynamic import callback was not specified error

The ‘Dynamic import callback was not specified’ error occurs when using dynamic imports incorrectly, typically when trying to use import() as a function call without proper promise handling or when using older patterns that expect callbacks.

How the Error Happens

❌ Error Scenario:

// ❌ This causes the error
import('./module.js', callback); // ❌ Dynamic import doesn't accept callback
// Error: Dynamic import callback was not specified

✅ Quick Fix - Proper Dynamic Import Usage

Solution 1: Use Promise-Based Dynamic Import

// ❌ Wrong way with callback
// import('./module.js', (module) => { ... });

// ✅ Correct way with promise
import('./module.js')
  .then((module) => {
    // ✅ Use the imported module
    module.myFunction();
  })
  .catch((error) => {
    console.error('Import failed:', error);
  });

Solution 2: Use Async/Await with Dynamic Import

// ✅ Use async/await for cleaner syntax
async function loadModule() {
  try {
    const module = await import('./module.js');
    return module.myFunction();
  } catch (error) {
    console.error('Import failed:', error);
  }
}

Solution 3: Proper Error Handling

// ✅ Handle dynamic import with proper error handling
async function safeImport(modulePath) {
  try {
    const module = await import(modulePath);
    return module;
  } catch (error) {
    if (error instanceof TypeError && error.message.includes('Dynamic import')) {
      console.error('Dynamic import error:', error.message);
    }
    throw error;
  }
}

Solution 4: Conditional Dynamic Import

// ✅ Use dynamic import conditionally
async function loadFeature(flag) {
  if (flag) {
    const { heavyFeature } = await import('./heavy-feature.js');
    return heavyFeature();
  }
  return null;
}