unit-testing

Deprecated. Use testing/extension-testing (references/unit.md) for MetaMask Extension, or testing/mobile-testing (references/unit.md) for MetaMask Mobile. Kept as a redirect stub for older installs and --include paths.

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Repository: MetaMask/skills
Last source activity: August 19, 2026 at 08:54
Detected SKILL.md language: English
Stars: 24
Forks: 11

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controller-guidelines

Authoring a MetaMask controller: BaseController or not, state metadata (`persist`, `anonymous`, `usedInUi`), `this.update`, the options-bag constructor, typed messenger actions. Use when writing or reviewing a controller, or changing what it persists or exposes to the UI. To wire one in, see `controller-integration`.

2026-09-03

controller-integration

Wire a new or existing controller — whether imported from a `@metamask/*-controller` npm package or defined locally in the repo — into the MetaMask Mobile Engine or the MetaMask Extension background. Use this skill when: adding a controller to Engine or to the extension's messenger-client init, creating a controller init function or messenger, delegating actions/events between controllers, adding a controller to EngineState/Engine.context or to MESSENGER_FACTORIES and the MessengerClient union, or debugging a controller whose state never reaches Redux/the UI or resets on restart.

2026-09-03

perf-hooks-effects

Extension UI hooks and effects: when not to use `useEffect`, dependency arrays, why `JSON.stringify` deps are never the fix, cascading effects, `AbortController` cleanup. Use when an effect loops or fires every render, deps are stringified to force equality, or state lands after unmount. Rendering goes to `perf-rendering`.

2026-09-03

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name	unit-testing
description	Deprecated. Use testing/extension-testing (references/unit.md) for MetaMask Extension, or testing/mobile-testing (references/unit.md) for MetaMask Mobile. Kept as a redirect stub for older installs and --include paths.
maturity	deprecated

Product	Install	Open
MetaMask Extension	`extension-testing`	`references/unit.md`
MetaMask Mobile	`mobile-testing`	`references/unit.md`

name	unit-testing
description	Deprecated. Use testing/extension-testing (references/unit.md) for MetaMask Extension, or testing/mobile-testing (references/unit.md) for MetaMask Mobile. Kept as a redirect stub for older installs and --include paths.
maturity	deprecated

Product	Install	Open
MetaMask Extension	`extension-testing`	`references/unit.md`
MetaMask Mobile	`mobile-testing`	`references/unit.md`

unit-testing

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Review the source files

Deprecated — use `extension-testing` or `mobile-testing`

Deprecated — use `extension-testing` or `mobile-testing`

unit-testing

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Review the source files

More from this repository

More from this repository

Deprecated — use extension-testing or mobile-testing

Deprecated — use extension-testing or mobile-testing

Deprecated — use `extension-testing` or `mobile-testing`

Deprecated — use `extension-testing` or `mobile-testing`