Fix for issues in #72

[snoop0x7b]

Description (*)

This PR fixes the issues outlined in Issue #72. It fixes the query-in-a-loop anti-pattern, the assumption that all items in a quote will be in a category (Which can cause a SQL error), the logic error where the category name array is overwritten for each item in the loop.

Bug

• 75 <Potential errors and performance issues in Tracker/InitiateCheckout>

Fixed Issues (if relevant)

1. magento-commerce/facebook-for-magento2#<72>: Potential errors and performance issues in Tracker/InitiateCheckout

Manual testing scenarios (*)

1. Create an item that has no categories, add it to the cart and check out. No error should occur.

Checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds are green)

[snoop0x7b]

Hey Facebook team

We're still maintaining this patch in our repository because we want into that SQL query issue I mentioned (In my issue report) any plans to merge this?

[zlik]

Hey @snoop0x7b, we reviewed your PR and it looks great! We will merge it in the private repo and release in the next version later this month. Thanks so much for your contribution!

[snoop0x7b]

Thanks! Looks like you guys merged a variant of this PR. I've closed this PR and updated my fork.