generate-test-cases

name	generate-test-cases
description	Use when source code changes under lib/jnpr/junos and the user wants unit tests created or updated for those changes.
allowed-tools	["read_file","file_search","grep_search","run_in_terminal","apply_patch","get_errors","get_changed_files"]
context	fork

Generate Unit Tests For PyEZ Source Changes

Goal

Create or update unit tests for code changes under lib/jnpr/junos, matching the existing project style in tests/unit.

Use This Skill When

• The user asks to write unit tests for modified source code.
• The requested scope is changes under lib/jnpr/junos.
• The user expects actual test files/edits, not only a coverage review.

Do Not Use This Skill When

• The task is only test planning or test-case enumeration without code changes.
• The task is functional/integration test authoring under tests/functional.

Required Workflow

1) Detect changed source files

Collect changed files and keep only paths under lib/jnpr/junos.

Preferred commands:

• git diff --name-only -- lib/jnpr/junos
• git diff --name-only --cached -- lib/jnpr/junos

If both are empty, ask for the exact files or compare against the upstream default branch:

• git diff --name-only origin/master...HEAD -- lib/jnpr/junos

2) Map source file to unit test location

Use these conventions first, then adjust to existing repository layout:

• lib/jnpr/junos/device.py -> tests/unit/test_device.py
• lib/jnpr/junos/console.py -> tests/unit/test_console.py
• lib/jnpr/junos/facts/<name>.py -> tests/unit/facts/test_<name>.py
• lib/jnpr/junos/factory/<name>.py -> tests/unit/factory/test_<name>.py
• lib/jnpr/junos/utils/<name>.py -> tests/unit/utils/test_<name>.py

If no matching test file exists, create one in the appropriate test subdirectory with naming test_<module>.py.

3) Learn local testing style before writing

Read nearby tests and follow established conventions:

• unittest/unittest2 style classes and test_* methods.
• Heavy use of unittest.mock (patch, MagicMock, mock_open).
• Keep fixtures and mocked RPC replies consistent with existing patterns in tests/unit/**/rpc-reply.

4) Implement tests for behavior, not implementation details

Cover only behavior changed by the source diff.

For each changed behavior, include positive and negative paths when applicable:

• successful path and return value/side effects
• raised exception or error mapping
• edge cases (None, empty input, malformed values)
• compatibility branches if present (for example Python-version or platform branches)

Avoid brittle assertions on internal private state unless that is the public contract used across this repo.

5) Keep edits minimal and scoped

• Do not refactor unrelated tests.
• Do not reformat unrelated files.
• Reuse existing helpers and fixtures before adding new ones.

6) Validate quickly with targeted test runs

Install required dependencies before executing tests:

• python3 -m pip install ntc_templates==1.4.1 textfsm==0.4.1
• python3 -m pip install -r requirements.txt
• python3 -m pip install nose2 junos-eznc

Run generated/updated testcase modules first (targeted validation), for example:

• nose2 -vvv tests.unit.facts.test_<name> --plugin nose2.plugins.junitxml --junit-xml
• nose2 -vvv tests.unit.test_<module> --plugin nose2.plugins.junitxml --junit-xml

Only after targeted tests pass, optionally run the broader unit suite:

• nose2 -vvv tests.unit --plugin nose2.plugins.junitxml --junit-xml

7) Report results

Summarize:

• changed source files detected
• test files created/updated
• scenarios covered
• test command(s) run and pass/fail outcome
• remaining risks or uncovered branches

Include the generated testcase execution output in verbose format from nose2 -vvv. At minimum, include:

• one line per testcase with status (... ok / ... FAIL / ... ERROR)
• final summary block (Ran X tests in Ys and final status)

Output Contract

When this skill is invoked, the final response must include:

1. Source-to-test mapping used.
2. Exact test files modified.
3. What behaviors each new/updated test verifies.
4. Validation command summary and outcomes.
5. Verbose generated testcase output (or key excerpt) from nose2 -vvv.