GabriM97 / App-Command-and-Architecture-Challenge

Laravel/Lumen Command App with Architecture Challenge

App Command and Architecture Challenge

This project case consists of 2 parts:

• The architecture challenge
• The coding challenge

The Architecture challenge

We have an issue related to our application load because of the huge amount of HTTP requests it receives. Those requests could be potentially processed asynchronously, as the client doesn't care about the response from our API gateway endpoint. Having that in mind, we decided to improve our application architecture by integrating a queue into the current system.

The assignment

You need to help us to build a new architecture design, where we will have a queue for collecting the requests, and a PHP application for consuming the messages from that queue. We need to make sure the application is consuming messages correctly and keeps track of errors. Sometimes there might be a timeout and then, after 1 minute, the same request would work again. Please write down a way of handling such cases.

From the consumer perspective, you should expect GET requests to an external API and a POST request to our internal API.

The architecture should be based on cloud services, be resilient and performant.

Please, provide the architecture design as a diagram. You can include the image directly, or a shareable link to diagrams.net or other preferred service.

Include a description of the architecture, and explain the motivations behind the choices made.

The coding challenge

The command banned-users:get in the Laravel project in this repository has been poorly implemented. There are several problems with the code quality, and the stakeholders reported that it also doesn't always output the correct results.

Its target is to get all the users that have been banned from the platform. It must accept some parameters:

• --no-admin, get all the users that have been banned and have no related admin role;
• --admin-only, get all the users that have been banned and have related admin role;
• --active-users-only, get all the users that have been banned and that have been activated;
• --with-trashed, get all the users that have been banned and that have been both deleted or not;
• --trashed-only, get all the users that have been banned and that have been both deleted;
• --with-headers, if set, print and save the column headers too;
• sort-by={field-name} (optional), the field on which sort the output;
• save-to={output/file/absolute/path}, if set, save the list on output file too.

It must output a list of sorted users, each one in a new line, indicating users' email, id and the date of the ban.

The assignment

You are required to:

1. Identify and correct all problems in the current source code.
2. Improve the coding style and make it compliant with the PSR guidelines.
3. Refactor the logic in the command to use services or helpers according to Laravel best practices.
4. Write unit tests for all the code you will implement.

Consider matching at least a 90% lines of code coverage. If you think it's not possible to reach it, please explain why.

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How to run the application

Requirements

• Install PHP 8.0
• Install Composer
• Install SQLite3

Run migrations and seed the database

php artisan migrate:fresh --seed

NOTE: This command will drop all the current tables in the database and run again all the migrations. Run php artisan db:seed if you only want to seed the DB.

Run the command

php artisan banned-users:get

You can add the --help option at the end of the command to show more information about the command, its arguments and options.

Run tests and code coverage (~94%)

Note: XDebug needs to be installed and enabled.

Tests only:

./vendor/bin/phpunit

Code coverage:

`XDEBUG_MODE=coverage ./vendor/bin/phpunit --coverage-text -c phpunit-coverage.xml`

Solution

The Architecture Challenge

The new proposed diagram can be found at the following link: https://drive.google.com/file/d/1BTs2UQ3M446NMGiXq3Lbisyz9ZWqvU05/view?usp=sharing

A description of all the components and the choices made: https://docs.google.com/document/d/1saAphgZ3vcKZCnTZYg3IJmOtbLHjHvhrcB4NlL-TbzE/edit?usp=sharing

The Coding Challenge

Refactored the GetBannedUsers command and fixed some logic bugs using Laravel services and best practices.

Added the following services and classes with main focus on re-usability:

• UserRepository
• GetBannedUsersInputValidator
• HasWritePermissionRecursive (Validation rule)
• WithoutField (Validation rule)
• UsersCommandsOptionsResolver
• CommandOutput Service

A test class has been added for each service with a total code coverage of ~94%

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Future improvements: The CommandOutput class should lift off the responsibility to write the output in a file and move away from the current "hacky" solution implemented. A good solution would be to implement another service, such as a CSV Writer, that will be responsible for this only. The requirement should be discussed with the stakeholders to understand better their needs, and if a CSV format would work for them.