Refactor external to use interfaces

[ekefan]

Description

The external package contains logic for sending requests to external services needed by hng_boilerplate. Currently, it has no factory for setting up the logic properly, there is no interface binding all external services hence mocking is difficult. And this package has no unit tests.

Acceptance Criteria

• Ensure all services dependent on external package and its logic retain their logic and functionality
• Expose the external package as an interface for communicating with any external package
• Update Mocks for the external package
• Include unit tests with good coverage for the package
• NightOwlDev will be handling all of these

Requirements

• N/A

Purpose

• To improve code modularity, testability, and adherence to the dependency inversion principle

Changes to be made:

The current external folder looks like this:

└── external/
    ├── external_models/
    │   └── ipstack.go
    ├── mocks/
    │   ├── ipstack_mocks/
    │   │   └── resolve_ip.go
    │   └── send_invites/
    │       └── send_invites.go
    ├── request/
    │   └── request.go
    ├── thirdparty/ipstack/
    │   ├── base.go
    │   └── resolve_ip.go
    └── send.go

I will be updating it to this:

└── external/
    ├── ipstack/
    │   ├── ipstack_test.go
    │   ├── ipstack.go
    │   └── model.go
    ├── mocks
    ├── request/
    │   ├── request_test.go
    │   └── request.go
    ├── external_test.go
    ├── external.go
    └── interface.go

• interface.go defines the required interface for external service interactions.

• external.go provides a generic function for sending external requests.

• request/request.go serves as a configurable external request handler using the factory pattern with options.

• mocks/ contains generated mocks to inject the external package when testing services that depend on it.

• ipstack/ contains implementation details for the IpStack API.

• *_test.go files contain unit test for functions.

• Update external to use interface Refactor the external package to use an interface #376

• Properly initialize external.ExternalRequest using factory method in every package using it

Expected Outcome

• Ability to choose which external service to communicate with at setup
• Every service dependent on external works as it should
• No failing tests