# Write Code

> The workflow for changing webui source code — understand, implement, test, changelog, lint. Use whenever writing or modifying source (not for docs-only edits). Enforces that every behavioral change ships with tests and a changelog entry.

- Skill: `eclipse-openvsx/write-code` (Agent Skill)
- Install (CLI): `npx skillmds@latest add eclipse-openvsx/write-code`
- Raw SKILL.md: https://api.skillmd.com/api/skills/eclipse-openvsx/write-code/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Productivity
- Author: eclipse-openvsx (https://skillmd.com/u/eclipse-openvsx)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/eclipse-openvsx/write-code

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# Changing webui code

## 1. Understand

- Read the files you're about to change in full before wide-ranging edits, and before editing a file you haven't inspected. Don't work from search snippets alone.
- Check `node_modules` for external API types instead of guessing.

## 2. Implement

- Match the style of the surrounding code.
- Keep comments short (1–3 lines): state the non-obvious constraint or rationale, never narrate what the code does.
- Ask before removing functionality that looks intentional. Don't preserve backward compatibility unless asked.

## 3. Test — required, not optional

Every behavioral change ships with tests. This is a gate, not a nicety:

- New behavior → add a test for it. Changed behavior → update the affected tests.
- Bug fix → add a **regression test** and apply the fail-first check: confirm it goes red without the fix, then restore. A fix without a test that pins it is incomplete.
- Follow the **`write-tests`** skill for setup, layout, and harness patterns.
- Run the file you touched, then the suite (`yarn test`); iterate until green.

If a change genuinely has no unit-testable surface (pure styling, config), say so explicitly rather than skipping silently.

Tests are how a change is verified — a passing, fail-first-checked test is the evidence the change works.

## 4. Changelog

Add an entry for the change under `## [next]` in `CHANGELOG.md`, in the right subsection (`### Added` / `### Changed` / `### Fixed` / `### Removed` / `### Dependencies`) — see AGENTS.md for the format rules. This covers product code; test-only, docs, and tooling changes don't get an entry.

## 5. Lint

`yarn lint` (full output, no `| tail`). Fix every error, warning, and info before considering the change done. Never run `yarn smoke-tests` unless asked. Never commit unless asked.