Resolving 'Cannot Read Property 'apply' of undefined' in Truffle External Scripts

If you are encountering the errors below while trying to execute your Truffle external script, please continue reading.

Errors Encountered:

TypeError: Cannot read property 'apply' of undefined
exception at require.js:128:1
TypeError: fn is not a function

For some reason, it was quite difficult to find a solution on how to correctly run an external Truffle script. After some time, I finally figured it out and am sharing it with the world:

// This is an example of a correctly structured external Truffle script.
// It addresses common issues like 'apply' of undefined or 'fn is not a function'
// by ensuring the script exports an async function that accepts a callback.

module.exports = async function(callback) {
  try {
    // Example: Interact with a deployed contract
    const MyContract = artifacts.require("MyContract"); // Replace with your contract name
    const instance = await MyContract.deployed();
    console.log("MyContract instance address:", instance.address);

    // Perform operations with your contract instance
    // Example: const value = await instance.getValue();
    // console.log("Contract value:", value.toString());

    // It's crucial to call the callback function to signal completion
    // when your script has finished executing successfully.
    callback();

  } catch (error) {
    // If any error occurs, log it and pass it to the callback
    // This allows Truffle to report the error appropriately.
    console.error("Error during script execution:", error);
    callback(error);
  }
};

// To run this script, save it as, for example, 'my_script.js' in your 'scripts/' directory
// Then execute it using: `truffle exec scripts/my_script.js`

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