I'm going to use PaymentTransaction as the example as I work through the conversion. This way I can note tips and tricks to save some future headache.

Steps

1. Change class PaymentTransaction to class PaymentTransaction extends Model
   • Running tests after results in a SQL Error about the table manuscripticon_test.payment_transactions does not exist.
     • Add static $table_name = "<sql table name>" to class.
2. Remove any private class variables associated with db columns (e.g. $created).
3. For PaymentTransaction many of the class variables were named with underscores in the way they are in the databases.
   • If this is not the case, the getters and setters need to be updated to reference the appropirate column variables. (e.g. $this->poNumber would need to become $this->po_number when the db column is named po_number.
     • My suggestion would be to keep all of the getters and setters, at least at this point. This will maintain compatability with existing code. I also personally like the getters and setters.
   • The next thing I did was run the tests. This caught variables in the FactoryMuffin object that were mis-named. (e.g. PaymentTransaction factory used invoiceId and needed to be changed to invoice_id. This is more than just in the FactoryMuffin definition, because there was some custom construction of these factories in various test suites.)
4. Remove any default constructors (including constructors where all parameters have default values assigned.
   • This will break lots of stuff.
     • In tests, I would recommend taking the constructor and substituting it for a Factory object with the parameters set via FactoryMuffin.
     • It is probably common that it was called with an existing id in order to load the record. This can be replaced with the ActiveRecord::find($id) method.
     • Complex replacements might be easier by passing an array into the ActiveRecord constructor setting attributes.
       • With ItemDiscount, it was initialized with new ItemDiscount(0, $lineItemId) to create a new ItemDiscount based on a previous LineItem. I solved this with: php ItemDiscount::create([ 'discounted_line_item_id => $lineItem->getLineItemId(), ]); I prefer the Model::create() method over new Model() because it includes a built-in save() giving the instance an id from the beginning which helps with associations and lessens code you have to write around the instance.
5. I elimitated code that would set improper data to an empty string in order to have it remain null. (e.g. check_deposit_date was set to a date if it was valid, else ''. I removed the else and chose to ignore any assignment. It simply stays null.
6. Look through CRUD methods implemented in the class (e.g. save(), delete(), etc). Remove them.
   • PaymentTransaction::save() was a little more complicated than a simple update of attributes in the database. It also called upon invoice to update its balance.
   • PaymentTransaction::save() also set the created attribute. I originally put a hook to set created after create, but that overwrote things set in the Factory. Plus there is a default value in the database, so it should be good to leave out.
7. If the class is not directly inhereting from Model (for instace, ItemDiscount) look for refernces to the parent's entities and make sure those are explicitly made in associations (has_one, has_many, etc.)
8. Associations sometimes break tests. For instance, making an associate with Invoice's billing_address and the Address model broke tests where random numbers were used for the billing address. Simply make an instance of the associated model and pass in the id.

Notes

Test Failures

• Many test failures will be resolved easily by remaning properties etc.
• I had test failues due to date issues. PaymentTransaction::check_deposit_date was being saved as a date while PaymentTransaction::created was datetime. The switch to ActiveRecord caused some weirdness in the Reporter that had an if/else query on those two fields. The factory was creating a date from created while expecting it to be a string. Simply setting it as a Date object resolved this issue.