Model/backend/export/README.md

🧪 Running Tests in PyCharm (macOS + pytest-postgresql)

Our test suite uses pytest and pytest-postgresql, which automatically spins up a temporary PostgreSQL instance.

On Linux (including GitHub Actions), PostgreSQL binaries are installed in standard system locations.
On macOS (Homebrew), they are not --- so PyCharm needs a small configuration tweak to locate pg_ctl.

This guide explains how to run and debug tests locally in PyCharm without modifying test code.

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✅ Prerequisites

Devcontainer

Postgres install is included in the devcontainer, so no additional setup is needed.

Running

make test

Will instigate the test suite, which will automatically start a temporary PostgreSQL instance.

Local MacOS

1. Install PostgreSQL via Homebrew:

brew install postgresql

2. Confirm pg_ctl exists:

which pg_ctl

Typical output:

/opt/homebrew/bin/pg_ctl

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🚀 Running Tests in PyCharm

Step 1 --- Create a PyCharm pytest Run Configuration

1. Open the test file.
2. Click the green ▶ next to the test.
3. Choose "Edit Run Configuration..."

You should see something like:

• Target: backend/export/tests/test_export.py
• Working directory: Project root (e.g.Model/)

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Step 2 --- Add Required Override (macOS Only)

In the Run Configuration:

➜ "Additional Arguments"

Add:

--override-ini=postgresql_exec=/opt/homebrew/bin/pg_ctl

This tells pytest-postgresql where pg_ctl lives on macOS.

Without this, PyCharm may fail with:

ExecutableMissingException: Could not found pg_config executable

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Step 3 --- Run or Debug

You can now:

• Click ▶ Run\
• Click 🐞 Debug\
• Set breakpoints normally

The temporary PostgreSQL instance will start automatically.

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🔍 Why This Is Needed

pytest-postgresql defaults to a Linux-style path:

/usr/lib/postgresql/<version>/bin/pg_ctl

That path exists on Ubuntu (CI), but not on macOS.

On macOS, Homebrew installs PostgreSQL in:

/opt/homebrew/bin/

The --override-ini flag safely overrides the executable path locally, without modifying:

• test files\
• conftest.py\
• pytest.ini\
• CI configuration

This ensures:

• ✅ Tests still work in GitHub Actions\
• ✅ Tests still work for Linux users\
• ✅ macOS developers can debug in PyCharm\
• ✅ No repository-specific hacks are required

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🛠 Optional: Using a Local .env File

If you prefer not to hardcode the override in the run configuration:

1. Create a local file:

<!-- -->

.env.local

2. Add:

<!-- -->

PYTEST_ADDOPTS=--override-ini=postgresql_exec=/opt/homebrew/bin/pg_ctl

3. In PyCharm:
   • Open the Run Configuration
   • Add .env.local under "Paths to .env files"

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🧪 Running Tests via Terminal (Recommended for CI Parity)

For normal execution outside PyCharm:

make test

These already work without additional configuration.

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🧠 Summary

Environment Works Without Override? Needs --override-ini?

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GitHub Actions (Linux) ✅ Yes ❌ No Linux local ✅ Yes ❌ No macOS terminal (tox) ✅ Yes ❌ No macOS PyCharm debugger ❌ No ✅ Yes