Convert function unit tests

[lopert]

Background

Fixes https://github.com/shop/issues-shopifyvm/issues/765
Converts existing unit tests to integration tests instead.

Also covers the rust side of https://github.com/shop/issues-shopifyvm/issues/755

Solution

Create a fixture representing each of the existing unit test scenarios.

Tophat

Run the generate command targetting this branch

shopify app generate extension -u https://github.com/Shopify/extensions-templates.git/\#lopert.convert-function-unit-tests

Checklist

• I have 🎩'd these changes

 ~/code/functions/dec-npm-rr-js  main ?24  npx vitest run

 RUN  v3.2.4 /Users/lopert/code/functions/dec-npm-rr-js

 ✓ extensions/cart-transformer/tests/default.test.js (1 test) 15501ms
 ✓ extensions/fulfillment-constraints/tests/default.test.js (1 test) 15565ms
 ✓ extensions/order-discount/tests/default.test.js (1 test) 15620ms
 ✓ extensions/discounts-allocator/tests/default.test.js (1 test) 15627ms
 ✓ extensions/cart-checkout-validation/tests/default.test.js (2 tests) 15822ms
 ✓ extensions/product-discount/tests/default.test.js (1 test) 16172ms
 ✓ extensions/discount-function/tests/default.test.js (8 tests) 16332ms
 ✓ extensions/payment-customization/tests/default.test.js (1 test) 16461ms
 ✓ extensions/delivery-customization/tests/default.test.js (1 test) 16606ms
 ✓ extensions/local-pickup-delivery-option-generators/tests/default.test.js (1 test) 16633ms
 ✓ extensions/shipping-discount/tests/default.test.js (1 test) 6212ms
 ✓ extensions/order-routing-location-rule/tests/default.test.js (1 test) 6466ms
 ✓ extensions/pickup-point-delivery-option-generators/tests/default.test.js (5 tests) 6448ms

 Test Files  13 passed (13)
      Tests  25 passed (25)
   Start at  17:00:41
   Duration  23.47s (transform 85ms, setup 0ms, collect 2.21s, tests 179.47s, environment 1ms, prepare 1.24s)

• I have squashed my commits into chunks of work with meaningful commit messages

[saga-dasgupta]

I think you haven't removed the rust unit tests.

[saga-dasgupta]

Tested and verified that all the unit tests have been replaced by fixtures and all the fixtures pass for cart validation, cart transform, delivery customization, discount and discount allocator functions for both Rust and JS.

[achitojha]

Verified all extension tests succeed and use the respective json files for Rust & Javascript versions of "Fulfillment constraint" / "Local pickup delivery option generator" / "Pickup point delivery option generator" / "Payment customization"