Pierre Testing and Verification Guide
pierrecomputer/pierre
Chooses the right verification step after a code change in Pierre's monorepo: format and lint, a typecheck, Bun unit tests, snapshots, or Playwright E2E.
A skill your agent uses when you need to write, review, or debug automated tests for applications built on the Jazz framework.
Install Jazz Testing
$ npx skills add garden-co/classic-jazz --skill jazz-testing -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install garden-co/classic-jazz jazz-testing --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/garden-co/classic-jazz.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.cursor/skills/jazz-testing .claude/skills/jazz-testing && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "jazz-testing" agent skill from https://github.com/garden-co/classic-jazz/tree/main/.cursor/skills/jazz-testing into .claude/skills/jazz-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "jazz-testing", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/garden-co/classic-jazz/tree/main/.cursor/skills/jazz-testingType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add garden-co/classic-jazz --skill jazz-testing -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install garden-co/classic-jazz jazz-testing --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/garden-co/classic-jazz.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.cursor/skills/jazz-testing .agents/skills/jazz-testing && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "jazz-testing" agent skill from https://github.com/garden-co/classic-jazz/tree/main/.cursor/skills/jazz-testing into .agents/skills/jazz-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "jazz-testing", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add garden-co/classic-jazz --skill jazz-testing -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install garden-co/classic-jazz jazz-testing --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/garden-co/classic-jazz.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.cursor/skills/jazz-testing .cursor/skills/jazz-testing && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "jazz-testing" agent skill from https://github.com/garden-co/classic-jazz/tree/main/.cursor/skills/jazz-testing into .cursor/skills/jazz-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "jazz-testing", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/garden-co/classic-jazz.git --path .cursor/skills/jazz-testing--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add garden-co/classic-jazz --skill jazz-testing -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install garden-co/classic-jazz jazz-testing --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/garden-co/classic-jazz.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.cursor/skills/jazz-testing .gemini/skills/jazz-testing && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "jazz-testing" agent skill from https://github.com/garden-co/classic-jazz/tree/main/.cursor/skills/jazz-testing into .gemini/skills/jazz-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "jazz-testing", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install garden-co/classic-jazz jazz-testingInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add garden-co/classic-jazz --skill jazz-testing -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/garden-co/classic-jazz.git skills-src && mkdir -p .github/skills && cp -r skills-src/.cursor/skills/jazz-testing .github/skills/jazz-testing && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "jazz-testing" agent skill from https://github.com/garden-co/classic-jazz/tree/main/.cursor/skills/jazz-testing into .github/skills/jazz-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "jazz-testing", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add garden-co/classic-jazz --skill jazz-testing -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install garden-co/classic-jazz jazz-testing --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/garden-co/classic-jazz.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.cursor/skills/jazz-testing .opencode/skills/jazz-testing && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "jazz-testing" agent skill from https://github.com/garden-co/classic-jazz/tree/main/.cursor/skills/jazz-testing into .opencode/skills/jazz-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "jazz-testing", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
jazz-testing- GitHub stars
- 2.5k
- Token cost
- ~1.6k tokens
- SKILL.md length
- 633 words
- Files
- 5 (incl. references)
- Skills in repo
- 8
- Repo updated
- First seen
- Licence
- MIT
At a glance
A skill your agent uses when you need to write, review, or debug automated tests for applications built on the Jazz framework.
- You need to write
- SKILL.md covers When to Use This Skill, Do NOT Use This Skill For, Key Heuristic for Agents and Core Concepts, plus 8 more sections
- Runs TypeScript scripts from its folder
- Debug automated tests for applications built on the Jazz framework
What it does
Jazz Testing is an agent skill from garden-co/classic-jazz. Use this skill when you need to write, review, or debug automated tests for applications built on the Jazz framework. This skill provides the correct architectural patterns for simulating local-first synchronization and multi-user environments without resorting to invalid mocking strategies.
Its SKILL.md is about 1.6k tokens, which your agent loads only when the skill is triggered. The skill folder holds 5 other files, including reference files (for example `references/jazz.svelte.ts`).
It sits in Testing & QA, covering Unit testing. It works with React and Svelte. The repository describes itself as: A new kind of database that's distributed across your frontend, containers, serverless functions and its own storage cloud. The licence is MIT.
When your agent uses it
- You need to write
- Debug automated tests for applications built on the Jazz framework
Example prompts
- “/jazz-testing”
Requirements
- Node.js
What it can do on your machine
Read from SKILL.md and the folder at commit 4f90501. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Ships script files (TypeScript), which the agent can run.
From the folder's file list and the shell code blocks in SKILL.md.
Network
Links to these hosts (documentation or services it may open):
github.comjazz.tools
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Jazz Testing loads about 1.6k tokens when it runs, and up to ~3k if it reads all its reference files. Until then it costs about 76 tokens; SKILL.md has 633 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from garden-co/classic-jazz at commit 4f90501, republished under its MIT licence (© garden-co). 633 words, ~1,623 tokens.
Download SKILL.mdSave it as
.claude/skills/jazz-testing/SKILL.md (or your agent's skills folder). This skill also uses 4 other files; get the full folder from GitHub.- name
- jazz-testing
- description
- Use this skill when you need to write, review, or debug automated tests for applications built on the Jazz framework. This skill provides the correct architectural patterns for simulating local-first synchronization and multi-user environments without resorting to invalid mocking strategies.
Jazz Testing
When to Use This Skill
- Writing unit or integration tests for apps using Jazz
- Simulating synchronisation for testing purposes
- Verifying permissions and security logic
- Testing UI components in various application states (Guest/Anonymous/Authenticated/Online/Offline)
- Debugging failing tests
Do NOT Use This Skill For
- Designing the initial data schema (use
jazz-schema-design - General React/Svelte UI layout questions unrelated to Jazz (for questions on Jazz integration with React/Svelte, use the
jazz-ui-developmentskill)
Key Heuristic for Agents
If you are about to suggest "mocking" any part of the data layer in the user's application, STOP and invoke this skill instead. This skill enforces the use of the official in-memory test sync node.
Core Concepts
Testing in Jazz requires understanding identity-based context and authentic synchronization. The framework's collaborative nature means tests must simulate real multi-user scenarios rather than mocking the sync layer.
Fundamental Principles
- NEVER Mock the Sync Layer: Avoid using generic mocking libraries (like Jest/Vitest mocks) for 'jazz-tools'
- In-Memory Synchronization: Always use a real in-memory sync node via
setupJazzTestSync()to allow authentic data flow between test identities - Identity-Based Context: Testing in Jazz is about "who" is performing the action. Manage the "Active Account" explicitly to verify permissions and ownership
Test Environment Setup
The virtual sync node must be initialized before tests run. It handles data synchronization in-memory and requires no manual cleanup between runs.
Example Setup:
import { setupJazzTestSync } from "jazz-tools/testing";
import { beforeEach, describe } from "vitest";
describe("Jazz Feature Test", () => {
beforeEach(async () => {
await setupJazzTestSync();
});
});Identity & Account Management
Testing in Jazz requires simulating multiple users to verify synchronization and security.
createJazzTestAccount
Used to create user accounts linked to the sync node.
AccountSchema: Pass your custom co.account schemaisCurrentActiveAccount: Set to true to automatically log the test runner into this accountcreationProps: Data passed to the account's migration function on creation if required
setActiveAccount
Used to switch between different users within a single test.
- Pattern: Create Account A -> Create Data -> Switch to Account B -> Attempt to Load/Modify Data
- Note: Once a CoValue is loaded, the permission context for that CoValue instance is fixed. Always use
.load(id)after switching accounts to load a new CoValue instance with the new permission context for that specific user
UI & Context Testing
UI tests must render components and hooks inside a Jazz-aware test harness (e.g. framework-specific render utilities that inject account, connection state, and sync context). In UI tests, assert observable loading state transitions, not internal CoValue mechanics.
Show full SKILL.md (254 more words)Show less
React
- Refer to the React provider and the context provided to it to see how to create a suitable harness for React tests.
Svelte
- Refer to the Svelte provider and the context provided to it to see how to create a suitable harness for Svelte tests.
Use the jazz-ui-development skill for questions on Jazz integration with React/Svelte.
Common Testing Patterns
Verifying Unauthorized Writes
const account1 = await createJazzTestAccount({ isCurrentActiveAccount: true });
const account2 = await createJazzTestAccount();
// Setup restricted group
const group = co.group().create();
group.addMember(account2, "reader");
const myMap = MyMap.create({ text: "Hi" }, { owner: group });
const mapId = myMap.$jazz.id;
// Switch to reader
setActiveAccount(account2);
// You *must* reload the CoValue with the new active account
const mapAsReader = await MyMap.load(mapId);
// Verify enforcement
expect(() => mapAsReader.$jazz.set("text", "some text")).toThrow();
// Note: myMap.$jazz.set() would *not* throw, as it was loaded with account1 as the active accountTesting Behavior without an Active Account
runWithoutActiveAccount(() => {
// Verify that protected actions fail when no account is active
expect(() => co.group().create()).toThrow();
});Common Pitfalls to Avoid
- CoValues not reloaded when active account changes: CoValues are always loaded with the active account at the time the CoValue is loaded, and this does not change even if the active account changes. CoValues loaded while
account1is the currently active account do not update their local permissions whensetActiveAccount(account2)is called; you MUST.load()a new instance of the CoValue - Missing Sync Setup: Ensure
setupJazzTestSync()is called - Attempting to test UI components outside of a Jazz context: Components relying on Jazz must have access to a Jazz context. Patterns for creating test contexts can be found in the framework-specific tests links
Quick Reference
Account switching:
Always reload CoValues after setActiveAccount() to get new permission context.
Sync setup:
Call setupJazzTestSync() in beforeEach for all Jazz tests.
UI testing:
Use a framework-specific Jazz test harness built on TestJazzContextManager.
References
Load these on demand, based on need:
- Official docs on testing: https://jazz.tools/docs/reference/testing.md
- Unit/integration test examples: https://github.com/garden-co/jazz/tree/main/packages/jazz-tools/src/tools/tests
- End-to-end examples: https://github.com/garden-co/jazz/tree/main/tests/e2e/tests
- React-specific tests: https://github.com/garden-co/jazz/tree/main/packages/jazz-tools/src/react-core/tests
- Svelte-specific tests: https://github.com/garden-co/jazz/tree/main/packages/jazz-tools/src/svelte/tests
When using an online reference via a skill, cite the specific URL to the user to build trust.
© garden-co, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 4 other files (references) in .cursor/skills/jazz-testing of garden-co/classic-jazz.
- SKILL.md
- references/Provider.svelte
- references/jazz.svelte.ts
- references/provider-context.tsx
- references/react-test-provider.tsx
Open the folder on GitHubat commit 4f90501
Compare with similar skills
Jazz Testing next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Jazz Testing this skillgarden-co/classic-jazz | 2.5k | — | ~1.6k | Automated safety check: Pass | MIT | |
| Pierre Testing and Verification Guidepierrecomputer/pierre | 6.2k | — | ~608 | Automated safety check: Pass | Apache-2.0 | |
| Svelte Testingspences10/sveltest | 113 | — | ~579 | Automated safety check: Pass | MIT | |
| Effect TStellahq/opensession | 392 | — | ~3.7k | Automated safety check: Pass | MIT | |
| Data Client React Testingreactive/data-client | 2k | — | ~1.5k | Automated safety check: Pass | Apache-2.0 | |
| Unit TestsKhan/wonder-blocks | 163 | — | ~4.2k | Automated safety check: Pass | MIT |
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More from garden-co/classic-jazz
All 8 skills in this repoJazz Performance
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A skill your agent uses when optimizing Jazz applications for speed, responsiveness, and scalability.
Jazz UI Development
garden-co/classic-jazz
A skill your agent uses when building, debugging, or optimizing Jazz applications.
Benchmarking
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A skill your agent uses when writing or running performance benchmarks for Jazz packages.
Jazz Permissions Security
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A skill your agent uses when designing data schemas, implementing sharing workflows, or auditing access control in Jazz applications.
Jazz Schema Design
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Design and implement collaborative data schemas using the Jazz framework.
Changeset
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Generate changeset files for versioning and changelog management in this monorepo.
Related
Categories
Questions about Jazz Testing
What does Jazz Testing do?
A skill your agent uses when you need to write, review, or debug automated tests for applications built on the Jazz framework. Jazz Testing is an agent skill from garden-co/classic-jazz. Use this skill when you need to write, review, or debug automated tests for applications built on the Jazz framework.
When should I use Jazz Testing?
Jazz Testing fits situations like: you need to write; debug automated tests for applications built on the Jazz framework.
How do I install Jazz Testing in Claude Code?
Run `npx skills add garden-co/classic-jazz --skill jazz-testing -a claude-code`. Or copy the skill folder (.cursor/skills/jazz-testing in garden-co/classic-jazz) into .claude/skills/jazz-testing in your project. Claude Code loads it when a task matches its description.
How do I install Jazz Testing in Codex?
Run `npx skills add garden-co/classic-jazz --skill jazz-testing -a codex`. Or copy the skill folder (.cursor/skills/jazz-testing in garden-co/classic-jazz) into .agents/skills/jazz-testing in your project. Codex loads it when a task matches its description.
Can I use Jazz Testing in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add garden-co/classic-jazz --skill jazz-testing -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/jazz-testing, .gemini/skills/jazz-testing, .github/skills/jazz-testing and .opencode/skills/jazz-testing in your project.
What does Jazz Testing need to run?
Going by SKILL.md and its folder, Jazz Testing needs TypeScript for the scripts in its folder. Our summary lists: Node.js.
Does Jazz Testing access the network?
SKILL.md names 2 domains. As links in the text: github.com and jazz.tools. This is read from the text; nothing was executed.
Is Jazz Testing safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Jazz Testing use?
Jazz Testing is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Jazz Testing use?
About 1.6k tokens (SKILL.md is roughly 6.5k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 1.4k tokens, read only when the agent opens those files.
What are the alternatives to Jazz Testing?
Skills that share tags, products or a category with Jazz Testing: Pierre Testing and Verification Guide (pierrecomputer/pierre, 6.2k stars), Svelte Testing (spences10/sveltest, 113 stars), Effect TS (tellahq/opensession, 392 stars) and Data Client React Testing (reactive/data-client, 2k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Jazz Testing?
garden-co (a GitHub organization) maintains it in garden-co/classic-jazz, which has 2,534 GitHub stars. The repository holds 8 skills in this directory. The repository was last updated on September 7, 2026.
Source: garden-co/classic-jazz on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.