Writing test cases for a CUJ

Tests live in the CUJ's file in the app's repo, under its ## Tests heading (the create-cujs skill writes those files). test-on-device runs them on the phone: CodeDroid follows the steps, then checks each expected line on the screen. Nothing is saved on the phone.

1. Know the journey

1. Find the CUJ files: cujs/ in the repo, or where the user says. No file for the journey the user means? Write it first, as the create-cujs skill does.
2. Read the file, its tests and its Source files, so tests name screens and buttons as the app does and don't repeat one already there.
3. If the phone is connected and the app installed, walk the journey once: open_app, then get_screen and tap (the codedroid-phone skill covers driving). Back out of anything that sends, buys, posts or deletes.

2. Pick the tests

The happy path first, then the edges that matter for this journey: empty or long input, an empty or long list, signed out, back or rotation in the middle, a PRD rule (a limit, an error message). One goal per test. Leave out offline: CodeDroid drives the phone over the internet, so it cannot run a test with the phone offline.

3. Write them

Append each under ## Tests:

### Follow a podcast from search

Steps:
1. Tap Search and type "Daily".
2. Open The Daily from the results.
3. Tap Follow.

Expected:
- The Follow button reads Following.
- The Daily is listed in the Following tab.

• Title: what it checks, a few words.
• Steps: what to do, as you would ask a person, from the CUJ's Starts state. Name the things to tap as the app shows them. No coordinates, no node numbers.
• Expected: what must be true after, one outcome per line, each something visible on the screen or in the app. Not how it got there. It must hold on any phone: no exact coordinates, distances, times or other values that change with the screen or the clock; say what must be there instead ("The episode shows how long it runs").

A test that would send, buy, post or delete something for real: keep it reversible (a draft, a cart left unpaid) and say so in its steps, or ask the user before writing it.

4. Report

List the tests added, by CUJ file. Offer to run them with test-on-device.

Never

• Force-stop, clear or uninstall com.codedroid.agent: it switches CodeDroid off.
• Write passwords, card numbers or other secrets into a test; say which test account to use instead.