go-testing

1## Activation Contract
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3Load this skill when writing or reviewing Go tests, adding coverage, testing Bubbletea/TUI flows, using `teatest`, or updating golden files.
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5## Hard Rules
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7- Prefer table-driven tests for multiple cases; use `t.Run(tt.name, ...)`.
8- Test behavior and state transitions, not implementation trivia.
9- Use `t.TempDir()` for filesystem tests; never rely on a real home directory.
10- Keep integration tests skippable with `testing.Short()` when they run external commands or slow flows.
11- For Bubbletea, test `Model.Update()` directly for state changes; use `teatest` only for interactive flows.
12- Golden files must be deterministic; update only through the repo's `-update` path and rerun tests without `-update`.
13- Use small mocks/interfaces around system or command execution boundaries.
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15## Decision Gates
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17| Target | Test pattern |
18|---|---|
19| Pure function or parser | Table-driven unit test. |
20| Error behavior | Explicit success and failure cases. |
21| File operations | `t.TempDir()` plus focused assertions. |
22| TUI state transition | Direct `Model.Update()` call with `tea.Msg`. |
23| Full TUI interaction | `teatest.NewTestModel()`. |
24| Rendered output | Golden file test. |
25| Real external command | Integration test; skip in `-short`. |
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27## Execution Steps
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291. Identify behavior under test and the smallest public boundary that proves it.
302. Choose the test pattern from the decision gate.
313. Name cases by scenario, not input mechanics.
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