Update app to use FastAPI instead of Flask and Flasgger

[silicoflare]

Changelog

• Migrated app and all dependencies from Flask + Flasgger to FastAPI
• Updated corresponding tests and utilities
• Added stricter type checking with updated request, response and profile models
• Added new health check endpoint at /health
• Migrated from flake8 to ruff linter
• Updated README and CONTRIBUTING files

[silicoflare]

One major change that I made is the auth endpoint. Instead of POST /authenticate, you can just do POST /. I felt that there was no need to make a separate endpoint for authentication if the only purpose of the app is authentication.

Let me know if I have to keep it or revert it.

[silicoflare]

One more thing, pesu-auth is now also available on https://pesu-auth.hy-pr.link. It has no downtime, and its response time is as fast as the Render endpoint. I am yet to setup CI/CD on that, but can I also add this link to the README?

[aditeyabaral]

No. Render will be our officially recognised deployment. You are free to deploy the API on your personal websites, but the Render endpoint is the only one being maintained and monitored actively by the devs. And point to note: Render does not have any downtimes anymore, we have mitigated that issue. We can remove the latency warning from the README but I would suggest still keeping it there.

[aditeyabaral]

I have reverted the authentication endpoint to /authenticate. The root route must never be an API endpoint, it should always redirect to the docs. And not to mention, the other potential services that change could break. I have also taken the liberty to clean up some files and logic in app.py, added some documentation, and also fixed/updated the tests and pre-commit files.

[achyu-dev]

This Field is giving me a depreceation warning when I am running the tests.

======================================================================== warnings summary ========================================================================= 
..\..\..\.conda\envs\test2\Lib\site-packages\pydantic\fields.py:1093: 19 warnings
  C:\Users\Achyuth S S\.conda\envs\test2\Lib\site-packages\pydantic\fields.py:1093: PydanticDeprecatedSince20: Using extra keyword arguments on `Field` is deprecated and will be removed. Use `json_schema_extra` instead. (Extra keys: 'example'). Deprecated in Pydantic V2.0 to be removed in V3.0. See Pydantic V2 Migration Guide at https://errors.pydantic.dev/2.11/migration/
    warn(

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
================================================================ 31 passed, 19 warnings in 20.11s ================================================================= 

although all tests are passing, this is just a warning.

One way to overcome, if we want to, is add a json_schema parameter wherever this Field is used

[achyu-dev]

The /authenticate is working on postman, just tested

[achyu-dev]

I still get this warning. Can we safely ignore this? As @ndigvijay had pointed before its just a VS Code extension issue 👍

  fields: list[Literal[*PESUAcademyConstants.DEFAULT_FIELDS]] | None = Field(

on this line

Unpacked arguments cannot be used in this contextPylance[reportInvalidTypeForm](https://github.com/microsoft/pylance-release/blob/main/docs/diagnostics/reportInvalidTypeForm.md)

Thus, when i run

pre-commit run --all-files

I get below error - >

          File "app/models/request.py", line 27
            fields: list[Literal[*PESUAcademyConstants.DEFAULT_FIELDS]] | None = Field(
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        SyntaxError: invalid syntax. Perhaps you forgot a comma?

Is there a workaround to fix this? @aditeyabaral

[achyu-dev]

I still get this warning. Can we safely ignore this? As @ndigvijay had pointed before its just a VS Code extension issue 👍

  fields: list[Literal[*PESUAcademyConstants.DEFAULT_FIELDS]] | None = Field(

on this line

Unpacked arguments cannot be used in this contextPylance[reportInvalidTypeForm](https://github.com/microsoft/pylance-release/blob/main/docs/diagnostics/reportInvalidTypeForm.md)

Thus, when i run

pre-commit run --all-files

I get below error - >

          File "app/models/request.py", line 27
            fields: list[Literal[*PESUAcademyConstants.DEFAULT_FIELDS]] | None = Field(
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        SyntaxError: invalid syntax. Perhaps you forgot a comma?

Is there a workaround to fix this? @aditeyabaral

For this, I did a temp fix, if u dont want this, please revert @aditeyabaral

[Copilot]

Pull Request Overview

This PR migrates the authentication API from Flask/Flasgger to FastAPI, updating the application to use modern async patterns and automatic API documentation generation. The migration includes comprehensive updates to the API structure, error handling, and testing infrastructure.

• Updated from Flask/Flasgger to FastAPI with automatic OpenAPI documentation
• Migrated synchronous route handlers to async functions with proper error handling
• Updated all test files to use FastAPI's TestClient instead of Flask's test client
• Enhanced Pydantic models with detailed field descriptions and validation

Reviewed Changes

Copilot reviewed 20 out of 22 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
app/app.py	Complete rewrite to use FastAPI with async handlers, structured error handling, and automatic OpenAPI docs
app/models/*.py	Enhanced Pydantic models with detailed field descriptions and modern type annotations
app/util.py	Removed Flask-specific validation function as FastAPI handles this automatically
app/pesu.py	Updated type hints to use modern union syntax and improved docstrings
tests/integration/test_*.py	Updated all integration tests to use FastAPI TestClient
tests/unit/test_*.py	Modified unit tests for async compatibility and updated assertions
pyproject.toml	Updated dependencies and added FastAPI, uvicorn, and testing packages

[aditeyabaral]

LGTM. Please pull the changes at your end and test.

[aditeyabaral]

This PR will resolve #45 and complete the entire migration to PESUAuth 2.0 #41

[aditeyabaral]

Updated README. Good to merge now.

[achyu-dev]

Looks Good to me. Please go ahead and merge