Python Testing Guide

01

Prerequisites

💡

Virtual environment check: Ensure (venv) appears as a prefix in your terminal prompt before proceeding. If it doesn't, run the activation command below from your project root.

bash

# Run from project root directory
source venv/Scripts/activate

02

Setup Steps

01

Pull Environment Variables

Fetch secrets from AWS Secrets Manager and write them to your local env file.

bash

aws secretsmanager get-secret-value \
    --secret-id local_master_secret \
  | jq -r '.SecretString' \
  | jq 'to_entries' \
  | jq -r 'map("\(.key)=\(.value|@sh)")[]' \
  > src/environments/.env.local

02

Navigate to Source Directory

bash

cd src

03

Install Dev Dependencies

bash

pip install -r requirements/requirements.dev.txt

04

Install Test Dependencies

bash

pip install -r requirements/requirements.test.txt

03

Running Tests

Base Command

bash

export STAGE='local' && python -m pytest {path/to/test_file.py} -vv

Flag Reference

Flag	Description
STAGE='local'	Environment flag — use `local` for local development runs
-vv	Verbose output — prints each test name and pass/fail result
-s	Disables stdout/stderr capture; use when you need to see `print()` output
{path}	Relative path to the target test file from the `src/` directory

04

Example Commands

Example 1

Order Eligibility Use-Case Test

bash

export STAGE="local" && python -m pytest -s \
    src/use_cases/orders/verify_order_eligibility_use_case_test.py

Example 2

Encryption Service Test

bash

export STAGE='local' && python -m pytest \
    tests/common/infrastructure/frameworks/encryption_service_test.py -vv

05

Local Debugging

Interactive Python Interpreter

bash

# Launch interpreter
py

# Exit interpreter
exit()

06

JSON Dumps

📂

Insert these snippets inside test methods to write repository data to disk for inspection. Add output files (invoice_data.json, payments.json, orders_data.json) to .gitignore to avoid accidental commits.

Payment Data

python

with open("payments.json", "w") as f:
    json.dump(
        [r.to_dict() for r in self.payment_repo.get_payments()], f
    )

Invoice Data

python

test_invoice_data = self.invoice_repo.get_invoices_as_dict().get("invoice_data")

with open("invoice_data.json", "w") as f:
    from json import dump
    dump(test_invoice_data, f)

Order Item Data · Future Reference

python

# Use while order_item testing
with open("orders_data.json", "w") as f:
    from json import dump
    dump(self.order_repo.get_orders_as_dict(), f)