Intro

e-food is a dummy e-commerce website. The service has been written in Go and I have used go-swagger framework. go-swagger is golang implementation of Swagger 2.0 (aka OpenAPI 2.0), it knows how to serialize and deserialize swagger specifications.

The go-swagger forces a developer to create documentation while developing an API. The boilerplate code is very helpful in enforcing micro service architecture code style.

The swagger.yaml of this code base can be found at ./api/swagger.yaml. The documentation can be seen by pasting swagger.yaml into swagger editor online

The UI for this backend service is available as e-food-client on github.

Reference:

1. https://github.com/go-swagger/go-swagger
2. https://goswagger.io/install.html

It includes:

1. Guest cart session. (After closing the browser, the app maintain the list of products for guest user)
2. User Registration
3. User Login using JWT with validity set to 300 mins
4. Cart Rules:
   • If 7 or more apples are added to the cart, a 10% discount is applied to all apples
   • For each set of 4 pears and 2 bananas, a 30% discount is applied, to each set.
   • These sets must be added to their own cart item entry.
   • If pears or bananas already exist in the cart, this discount must be recalculated when new pears or bananas are added
5. Coupons can be generated. To generate a coupon, make a POST call to below endpoint:

   http://127.0.0.1:8080/v1/generateCouponCode

   • coupon code can be used to get a 30% discount on oranges, if applied to the cart, otherwise oranges are full price
   • the /generateCouponCode can easily be configured to generate different coupons with different product rules
   • a coupon can only be applied once (this is also configurable in /generateCouponCode which accepts userLimit to restrict the number of times a coupon can be consumed)
   • Has a configurable expiry timeout (90 seconds (10 sec is too short to test) has been hard-coded in API for testing purposes) once generated.
6. Checkout cart shows:
   • Total price
   • Total Saving
7. In a cart you can :
   • Adjust quantity.
   • Delete items from the cart.
   • Apply coupons. ( option available during checkout time only )
8. A test payment gateway has been provided to complete the journey. ( https://razorpay.com/)
9. Architecture diagram can be found at ./resources/e-food.drawio and can be opened using http://draw.io/
10. Order Management, Inventory management & User address have not been implemented yet.
11. A sample unit test file can be found at ./handlers/delete_guest_cart_item_test.go
12. In case a new rule has to be added for cart items, make sure the productId defined in rules.json and ecommerce.product table are in sync
13. To modify coupon rule, make changes in hardcoded value in ./handlers/post_generate_coupon.go . The values can easily be made flexible by commenting out below lines in the file. Please note that the syntax are follows the same pattern as rules.json:

defaultRuleSet := "{"ruleId": "c1","discount": 30.00,"filters": {"3": {"minQuantity": 1}}}"

Cmd to generate new changes of swagger go into ./api folder and run below command :

swagger generate server -f swagger.yaml --default-scheme http --exclude-main

Prerequisite:

• Install mysql
• create a schema named ecommerce with: [ TODO: We can create a separate user rather than using root]

username = root, password = root

• Connect to schema and execute file create.sql located in repository under path:

./resources/create.sql

• Install dependencies using go.mod file

• To run the repository locally :

go run cmd\e-food-server\main.go --scheme http --port=8080

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Note: Other areas of improvement has been noted down into to-do.txt file of this repo