docs: add note about tests

README.md

@@ -8,13 +8,19 @@ This repository consists of a Rust web server using [axum](https://docs.rs/axum/
 
 It is recommended to use the Nix development shell at the root of this repository to automatically install all necessary dependencies (excluding Docker, which must be installed manually).
 
-### Environment Variables
-
-- `DATABASE_URL` (default: `postgres://olly:password@0.0.0.0:5432/olly`) - specifies the address of the PostgreSQL database
-
 ### Steps
 
 1. Start the PostgreSQL database: `docker compose up`
 2. Migrate the database: `cargo run --package migration up`
 3. Start the `axum` server: `cargo run`
 4. Run the web client: `cd client && npm run dev`
+
+### Testing
+
+**Frontend:** Nothing automated yet.
+
+**Backend:** Use Cargo's built in runner (`cargo test`). After each subsequent execution, `sea-orm-cli migrate fresh` must be run to ensure that app state is refreshed to defaults. Otherwise, some tests may fail.
+
+## Environment Variables
+
+- `DATABASE_URL` (default: `postgres://olly:password@0.0.0.0:5432/olly`) - specifies the address of the PostgreSQL database