Add tests that send API requests and assert things about API responses

[eecavanna]

On this branch, I added the first few tests that hit the BERtron API.

I also fixed a type inconsistency, where—as far as our type hints indicate—we could have passed a non-string value to a parameter (i.e. the version parameter of the FastAPI function) designed to be passed a string.

I also introduced httpx as a development dependency. It is a dependency of FastAPI's TestClient class.

I did not include any tests that involve the MongoDB server. I think that will happen alongside #53, separately from this.

[Copilot]

Pull Request Overview

This PR introduces the first set of API tests for the BERtron FastAPI application, adding test infrastructure to validate endpoint responses. The changes include setting up a test client, implementing basic endpoint tests, and fixing a type inconsistency in the FastAPI version parameter.

• Adds test infrastructure with FastAPI TestClient and pytest fixtures
• Implements tests for root redirect and version endpoint response validation
• Fixes type consistency by ensuring version parameter is explicitly a string

Reviewed Changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/tests/test_server.py	New test file with API endpoint tests using FastAPI TestClient
src/server.py	Fixes version parameter type by adding explicit string formatting
src/models.py	Adds strict validation configuration to prevent extra fields in responses
src/README.md	Updates documentation to include tests directory
pyproject.toml	Adds httpx dependency required for FastAPI TestClient

Comments suppressed due to low confidence (1)

src/tests/test_server.py:18

• [nitpick] The variable name test_client inside the fixture function shadows the fixture name itself. Consider renaming the variable to client or api_client for clarity.

    test_client = TestClient(app)

[jeff-cohere]

Looks great. Thanks @eecavanna !

[eecavanna]

Thanks, @jeff-cohere! Merging.