Go Testing Agent Skill

Activation Contract

Load this skill when writing or reviewing Go tests, adding coverage, testing Bubbletea/TUI flows, using teatest, or updating golden files.

Hard Rules

• Prefer table-driven tests for multiple cases; use t.Run(tt.name, ...).
• Test behavior and state transitions, not implementation trivia.
• Use t.TempDir() for filesystem tests; never rely on a real home directory.
• Keep integration tests skippable with testing.Short() when they run external commands or slow flows.
• For Bubbletea, test Model.Update() directly for state changes; use teatest only for interactive flows.
• Golden files must be deterministic; update only through the repo's -update path and rerun tests without -update.
• Use small mocks/interfaces around system or command execution boundaries.

Decision Gates

| Target | Test pattern |

|---|---|

| Pure function or parser | Table-driven unit test. |

| Error behavior | Explicit success and failure cases. |

| File operations | t.TempDir() plus focused assertions. |

| TUI state transition | Direct Model.Update() call with tea.Msg. |

| Full TUI interaction | teatest.NewTestModel(). |

| Rendered output | Golden file test. |

| Real external command | Integration test; skip in -short. |

Execution Steps

• Identify behavior under test and the smallest public boundary that proves it.
• Choose the test pattern from the decision gate.
• Name cases by scenario, not input mechanics.
• Assert outputs, errors, state, and side effects explicitly.
• Run the narrow package test first, then the relevant broader suite.
• For golden updates: run with -update, inspect diff, then rerun without -update.

Output Contract

Report test files changed, scenarios covered, commands executed, golden files updated, and any skipped integration scope.

References

• references/examples.md — compact table-driven, Bubbletea, teatest, golden, and command examples.