---
title: "React 19 Test Migration Patterns - Air Market"
description: "You upgraded to React 19 and now the tests fail for reasons that have nothing to do with your app. This shows the before and after for the test-file changes that upgrade forces. Reach for it when you…"
canonical: "https://airmarket.ai/app/react19-test-patterns"
---

[Air Market](/) / [Developer Tools](/category/devtools) / React 19 Test Migration Patterns

Skill by [GitHub](/@github)

# React 19 Test Migration Patterns

Get the test suite green again after a React 19 bump

## What this does

You upgraded to React 19 and now the tests fail for reasons that have nothing to do with your app. This shows the before and after for the test-file changes that upgrade forces. Reach for it when you are working through a broken suite after the bump.

### Top 3 things it does for you

- Fix act() imports that moved in React 19
- Replace test code that relied on Simulate
- Deal with StrictMode calling things a different number of times

## Information

**React 19 Test Migration Patterns at a glance**

|  |  |
| --- | --- |
| Kind | Skill |
| Publisher | [GitHub](/@github) |
| Category | [Developer Tools](/category/devtools) |
| Works with | Agent Skills - an open standard supported by 40+ agents |
| Size | 3 KB |
| Licence | MIT |
| Repository | [github/awesome-copilot](https://github.com/github/awesome-copilot/tree/811ed362dd9cdbbc83efc10e43039598654a7dda/skills/react19-test-patterns) |
| GitHub stars | 38,187 (as of Nov 2026) |
| Installs | 1,262, counted by skills.sh (Nov 2026) |

## Security report

**Verified.** AIR scanned this exact version of React 19 Test Migration Patterns and flagged nothing. AIR's verdict: **safe**.

**What React 19 Test Migration Patterns's check was run against**

|  |  |
| --- | --- |
| Commit | 811ed362dd9cdbbc83efc10e43039598654a7dda |
| Content hash | af5138ee2ddd741448452206e6c07bf8dd38780d82c4099a79e5656dfbe91da9 |
| Files read | [Browse the files at this exact commit](https://github.com/github/awesome-copilot/blob/811ed362dd9cdbbc83efc10e43039598654a7dda/skills/react19-test-patterns/SKILL.md) |

A scan is named by the exact content it read, not by a version number. A different version is a different artifact, and nothing here applies to a version AIR has not scanned.

[Read the full security report for React 19 Test Migration Patterns](/security/react19-test-patterns)

## About React 19 Test Migration Patterns

Before-and-after patterns for bringing test files up to React 19 compatibility.

It covers act() imports, the removal of Simulate, and the change in how many times StrictMode calls things.

## What's inside

- SKILL.md - instructions

## Questions

### Is React 19 Test Migration Patterns safe to install?

AIR scanned this exact version of React 19 Test Migration Patterns and flagged nothing. AIR's verdict: safe. The verdict is named by the content that was read, at commit 811ed362dd9c, so it cannot drift onto a version nobody scanned. The full report is at https://airmarket.ai/security/react19-test-patterns.

### How do I install React 19 Test Migration Patterns?

Open https://airmarket.ai/app/react19-test-patterns on Air Market and use the install action: Air Market hands Claude a prompt naming this exact skill, and Claude sets it up. Source, pinned to the exact commit this listing describes: https://github.com/github/awesome-copilot/tree/811ed362dd9cdbbc83efc10e43039598654a7dda/skills/react19-test-patterns. Install from that link, not the branch.

## Related on Air Market

- [More Developer Tools listings](/category/devtools)
- [Everything by GitHub](/@github)

---

Canonical URL: <https://airmarket.ai/app/react19-test-patterns>