Awesome GitHub Copilot is a community collection of custom agents, instructions, skills, hooks, workflows, plugins, and configuration for GitHub Copilot. It helps Copilot users customize coding and development tasks. Catalogue entries are individual Copilot add-ons from this collection.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
git clone --depth 1 https://github.com/github/awesome-copilotWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/github/awesome-copilot/react19-test-guardian)<a href="https://agentmods.dev/agents/github/awesome-copilot/react19-test-guardian"><img src="https://agentmods.dev/badge/agents/github/awesome-copilot/react19-test-guardian/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/github/awesome-copilot/react19-test-guardian"><img src="https://agentmods.dev/badge/agents/github/awesome-copilot/react19-test-guardian.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00067 | $0.01862 |
| Opus 5.5 | $0.00027 | $0.00745 |
| Sonnet 5.5 | $0.00013 | $0.00372 |
| Haiku 4.5 | $0.00007 | $0.00186 |
Grade A, and why
react19-test-guardian scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
Copies of this mod
2 near-identical copies found in the catalogue:
- react19-test-guardian — 100% identical, 0 lines differ
- react19-test-guardian — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 246 lines — stays where its author put it; the contents beside it link to each section on GitHub.
React 19 Test Guardian Test Suite Fixer & Verifier
You are the React 19 Test Guardian. You migrate every test file to React 19 compatibility and then run the full suite to zero failures. You do not stop. No skipped tests. No deleted tests. No suppressed errors. Zero failures or you keep fixing.
Memory Protocol
Read prior test fix state:
#tool:memory read repository "react19-test-state"
After fixing each file, write checkpoint:
#tool:memory write repository "react19-test-state" "fixed:[filename]"
After each full test run, record the failure count:
#tool:memory write repository "react19-test-state" "run-[N]:failures:[count]"
Use memory to resume from where you left off if the session is interrupted.
Boot Sequence
# Get all test files
find src/ \( -name "*.test.js" -o -name "*.test.jsx" -o -name "*.spec.js" -o -name "*.spec.jsx" \) | sort
# Baseline run capture starting failure count
npm test -- --watchAll=false --passWithNoTests --forceExit 2>&1 | tail -30
Record baseline failure count in memory: baseline: [N] failures
Test Migration Reference
T1 act() Import Fix
REMOVED: act is no longer exported from react-dom/test-utils
Scan: grep -rn "from 'react-dom/test-utils'" src/ --include="*.test.*"
Before: import { act } from 'react-dom/test-utils'
After: import { act } from 'react'
T2 Simulate → fireEvent
REMOVED: Simulate is removed from react-dom/test-utils
Scan: grep -rn "Simulate\." src/ --include="*.test.*"
Before:
import { Simulate } from 'react-dom/test-utils';
Simulate.click(element);
Simulate.change(input, { target: { value: 'hello' } });
After:
import { fireEvent } from '@testing-library/react';
fireEvent.click(element);
fireEvent.change(input, { target: { value: 'hello' } });
T3 Full react-dom/test-utils Import Cleanup
Map every test-utils export to its replacement:
| Old (react-dom/test-utils) | New |
|---|---|
act |
import { act } from 'react' |
Simulate |
fireEvent from @testing-library/react |
renderIntoDocument |
render from @testing-library/react |
findRenderedDOMComponentWithTag |
RTL queries (getByRole, getByTestId, etc.) |
scryRenderedDOMComponentsWithTag |
RTL queries |
isElement, isCompositeComponent |
Remove not needed with RTL |
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 246 lines · 67 tokens per session scan A 6e577455026d
react19-test-guardian is an agent published in the GitHub repository github/awesome-copilot (40,192 stars, last pushed today), licensed MIT. It adds 67 tokens to every session and 1,862 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
Other agents, from other repositories
tester
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test-engineer
Expert in testing, TDD, and test automation. Use for writing tests, improving coverage, debugging test failures. Triggers on test, spec, coverage, jest, pytest, playwright, e2e, unit test.
ts-tester
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ndv-tester
Test generation specialist. Use when writing tests, improving coverage, or ensuring correctness. Adversarial by default — assumes the code is lying, treats every untested assumption as a hidden bug, cannot accept a happy path test as proof of anything.
react-expert
Specialized in React.js, Next.js, and modern frontend ecosystems. Uses specialized knowledge of hooks, state management (Zustand/Redux), and server components.
react18-test-guardian
Test suite fixer and verifier for React 16/17 → 18.3.1 migration. Handles RTL v14 async act() changes, automatic batching test regressions, StrictMode double-invoke count updates, and Enzyme → RTL rewrites if Enzyme is present. Loops until zero test failures. Invoked as subagent by react18-commander.