Agent skill

Regression Testing

by proffesor-for-testing in proffesor-for-testing/agentic-qe

Strategic regression testing with test selection, impact analysis, and continuous regression management.

MITAuto-check passedTesting & QA

Install Regression Testing

skills CLI

$ npx skills add proffesor-for-testing/agentic-qe --skill regression-testing -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install proffesor-for-testing/agentic-qe regression-testing --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/proffesor-for-testing/agentic-qe.git skills-src && mkdir -p .claude/skills && cp -r skills-src/assets/skills/regression-testing .claude/skills/regression-testing && rm -rf skills-src

Use ~/.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/

Paste into Claude Code

Install the "regression-testing" agent skill from https://github.com/proffesor-for-testing/agentic-qe/tree/main/assets/skills/regression-testing into .claude/skills/regression-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "regression-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

$skill-installer install https://github.com/proffesor-for-testing/agentic-qe/tree/main/assets/skills/regression-testing

Type 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.

skills CLI

$ npx skills add proffesor-for-testing/agentic-qe --skill regression-testing -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install proffesor-for-testing/agentic-qe regression-testing --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/proffesor-for-testing/agentic-qe.git skills-src && mkdir -p .agents/skills && cp -r skills-src/assets/skills/regression-testing .agents/skills/regression-testing && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "regression-testing" agent skill from https://github.com/proffesor-for-testing/agentic-qe/tree/main/assets/skills/regression-testing into .agents/skills/regression-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "regression-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.

skills CLI

$ npx skills add proffesor-for-testing/agentic-qe --skill regression-testing -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install proffesor-for-testing/agentic-qe regression-testing --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/proffesor-for-testing/agentic-qe.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/assets/skills/regression-testing .cursor/skills/regression-testing && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "regression-testing" agent skill from https://github.com/proffesor-for-testing/agentic-qe/tree/main/assets/skills/regression-testing into .cursor/skills/regression-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "regression-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

$ gemini skills install https://github.com/proffesor-for-testing/agentic-qe.git --path assets/skills/regression-testing

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add proffesor-for-testing/agentic-qe --skill regression-testing -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install proffesor-for-testing/agentic-qe regression-testing --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/proffesor-for-testing/agentic-qe.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/assets/skills/regression-testing .gemini/skills/regression-testing && rm -rf skills-src

Use ~/.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/

Paste into Gemini CLI

Install the "regression-testing" agent skill from https://github.com/proffesor-for-testing/agentic-qe/tree/main/assets/skills/regression-testing into .gemini/skills/regression-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "regression-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.

GitHub CLI

$ gh skill install proffesor-for-testing/agentic-qe regression-testing

Installs 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).

skills CLI

$ npx skills add proffesor-for-testing/agentic-qe --skill regression-testing -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/proffesor-for-testing/agentic-qe.git skills-src && mkdir -p .github/skills && cp -r skills-src/assets/skills/regression-testing .github/skills/regression-testing && rm -rf skills-src

Use ~/.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/

Paste into GitHub Copilot

Install the "regression-testing" agent skill from https://github.com/proffesor-for-testing/agentic-qe/tree/main/assets/skills/regression-testing into .github/skills/regression-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "regression-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.

skills CLI

$ npx skills add proffesor-for-testing/agentic-qe --skill regression-testing -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install proffesor-for-testing/agentic-qe regression-testing --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/proffesor-for-testing/agentic-qe.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/assets/skills/regression-testing .opencode/skills/regression-testing && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "regression-testing" agent skill from https://github.com/proffesor-for-testing/agentic-qe/tree/main/assets/skills/regression-testing into .opencode/skills/regression-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "regression-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: regression-testing
GitHub stars: 494
Token cost: ~1.5k tokens
SKILL.md length: 296 words
Files: 4 (incl. scripts)
Skills in repo: 111
Repo updated: Oct 4, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Strategic regression testing with test selection, impact analysis, and continuous regression management.

Works in 5 steps: ANALYZE what changed (git diff, impact… → SELECT tests based on change + risk (not… → RUN in priority order (smoke → selective… → …
Verifying fixes dont break existing functionality
SKILL.md covers Quick Reference Card, Change-Based Test Selection, CI/CD Integration and Agent-Driven Regression, plus 5 more sections
Planning regression suites

What it does

Regression Testing is an agent skill from proffesor-for-testing/agentic-qe. Strategic regression testing with test selection, impact analysis, and continuous regression management. Use when verifying fixes don't break existing functionality, planning regression suites, or optimizing test execution for faster feedback.

Its SKILL.md is about 1.5k tokens, which your agent loads only when the skill is triggered. The skill folder holds 6 other files, including scripts (for example `evals/regression-testing.yaml`, `schemas/output.json` and `scripts/validate-config.json`).

It sits in Testing & QA, covering QA and bug reports. The repository describes itself as: Agentic QE Fleet is an open-source AI-powered QA/QE platform designed for use with Coding Agents (works best with Claude Code) featuring specialized agents and skills to support… The licence is MIT.

When your agent uses it

Verifying fixes dont break existing functionality
Planning regression suites
Optimizing test execution for faster feedback

Example prompts

“/regression-testing”

Workflow steps

5 steps, taken from the first numbered list in SKILL.md.

ANALYZE what changed (git diff, impact analysis)
SELECT tests based on change + risk (not everything)
RUN in priority order (smoke → selective → full)
OPTIMIZE execution (parallel, sharding)
MONITOR suite health (flakiness, execution time)

What it can do on your machine

Read from SKILL.md and the folder at commit 829d030. 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 1 file in scripts/, which the agent can run.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
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

Regression Testing loads about 1.5k tokens when it runs. Until then it costs about 66 tokens; SKILL.md has 296 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~66
When it runs · the whole SKILL.md, loaded when a task matches: ~1.5k

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); the scripts in this folder are not scanned.

SKILL.md

The full file from proffesor-for-testing/agentic-qe at commit 829d030, republished under its MIT licence (© proffesor-for-testing). 296 words, ~1,489 tokens.

Download SKILL.mdSave it as .claude/skills/regression-testing/SKILL.md (or your agent's skills folder). This skill also uses 3 other files; get the full folder from GitHub.

name: regression-testing
description: Strategic regression testing with test selection, impact analysis, and continuous regression management. Use when verifying fixes don't break existing functionality, planning regression suites, or optimizing test execution for faster feedback.
category: specialized-testing
priority: high
tokenEstimate: 1000
agents: qe-regression-risk-analyzer, qe-test-executor, qe-coverage-analyzer
implementation_status: optimized
optimization_version: 1
last_optimized: 2025-12-02
quick_reference_card: true
tags: regression, test-selection, impact-analysis, ci-cd, change-based, risk-based
trust_tier: 3

Regression Testing

<default_to_action> When verifying changes don't break existing functionality:

ANALYZE what changed (git diff, impact analysis)
SELECT tests based on change + risk (not everything)
RUN in priority order (smoke → selective → full)
OPTIMIZE execution (parallel, sharding)
MONITOR suite health (flakiness, execution time)

Quick Regression Strategy:

Per-commit: Smoke + changed code tests (5-10 min)
Nightly: Extended regression (30-60 min)
Pre-release: Full regression (2-4 hours)

Critical Success Factors:

Smart selection catches 90% of regressions in 10% of time
Flaky tests waste more time than they save
Every production bug becomes a regression test </default_to_action>

Quick Reference Card

When to Use

After any code change
Before release
After dependency updates
After environment changes

Test Selection Strategies

Strategy	How	Reduction
Change-based	Git diff analysis	70-90%
Risk-based	Priority by impact	50-70%
Historical	Frequently failing	40-60%
Time-budget	Fixed time window	Variable

Change-Based Test Selection

typescript

// Analyze changed files and select impacted tests
function selectTests(changedFiles: string[]): string[] {
  const testsToRun = new Set<string>();

  for (const file of changedFiles) {
    // Direct tests
    testsToRun.add(`${file.replace('.ts', '.test.ts')}`);

    // Dependent tests (via coverage mapping)
    const dependentTests = testCoverage[file] || [];
    dependentTests.forEach(t => testsToRun.add(t));
  }

  return Array.from(testsToRun);
}

// Example: payment.ts changed
// Runs: payment.test.ts, checkout.integration.test.ts, e2e/purchase.test.ts

CI/CD Integration

yaml

# .github/workflows/regression.yml
jobs:
  quick-regression:
    runs-on: ubuntu-latest
    timeout-minutes: 15
    steps:
      - name: Analyze changes
        id: changes
        uses: dorny/paths-filter@v2
        with:
          filters: |
            payment:
              - 'src/payment/**'
            auth:
              - 'src/auth/**'

      - name: Run affected tests
        run: npm run test:affected

      - name: Smoke tests (always)
        run: npm run test:smoke

  nightly-regression:
    if: github.event_name == 'schedule'
    timeout-minutes: 120
    steps:
      - run: npm test -- --coverage

Agent-Driven Regression

typescript

// Smart test selection
await Task("Regression Analysis", {
  pr: 1234,
  strategy: 'change-based-with-risk',
  timeBudget: '15min'
}, "qe-regression-risk-analyzer");

// Returns:
// {
//   mustRun: ['payment.test.ts', 'checkout.integration.test.ts'],
//   shouldRun: ['order.test.ts'],
//   canSkip: ['profile.test.ts', 'search.test.ts'],
//   estimatedTime: '12 min',
//   riskCoverage: 0.94
// }

// Generate regression test from production bug
await Task("Bug Regression Test", {
  bug: { id: 'BUG-567', description: 'Checkout fails > 100 items' },
  preventRecurrence: true
}, "qe-test-generator");

Agent Coordination Hints

Memory Namespace

aqe/regression-testing/
├── test-selection/*     - Impact analysis results
├── suite-health/*       - Flakiness, timing trends
├── coverage-maps/*      - Test-to-code mapping
└── bug-regressions/*    - Tests from production bugs

Fleet Coordination

typescript

const regressionFleet = await FleetManager.coordinate({
  strategy: 'comprehensive-regression',
  agents: [
    'qe-regression-risk-analyzer',  // Analyze changes, select tests
    'qe-test-executor',             // Execute selected tests
    'qe-coverage-analyzer',         // Analyze coverage gaps
    'qe-quality-gate'               // Go/no-go decision
  ],
  topology: 'sequential'
});

risk-based-testing - Risk-based prioritization
test-automation-strategy - Automation pyramid
continuous-testing-shift-left - CI/CD integration

Remember

With Agents: qe-regression-risk-analyzer provides intelligent test selection achieving 90% defect detection in 10% of execution time. Agents generate regression tests from production bugs automatically.

Skill Composition

Test failing? → Use /test-failure-investigator to diagnose root cause
File a bug → Use /bug-reporting-excellence for proper bug reporting
Test selection → Use /risk-based-testing for risk-based prioritization

Gotchas

Agent defaults to "run everything" despite being told to select — explicitly constrain with --affected or file list
Change-based selection misses transitive dependencies — a model change can break a controller test 3 hops away
Flaky tests in regression suites erode trust faster than missing tests — quarantine immediately, don't skip
Agent may report "0 regressions" when tests simply weren't run — verify test count in output, not just pass/fail
Running full regression in containers often OOMs — use --workers=2 and --shard for CI environments

Files

SKILL.md and 3 other files (scripts) in assets/skills/regression-testing of proffesor-for-testing/agentic-qe.

SKILL.md
evals/regression-testing.yaml
schemas/output.json
scripts/validate-config.json

Open the folder on GitHubat commit 829d030

Compare with similar skills

Regression 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.

Regression Testing compared with similar skills
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Regression Testing this skillproffesor-for-testing/agentic-qe	494	—	~1.5k	Automated safety check: Pass	MIT	3 days ago
Reproduce Chat Statesdifferent-ai/openwork	24k	—	~673	Automated safety check: Pass	Custom licence	today
Dynamo Jira TicketDynamoDS/Dynamo	2k	—	~1.1k	Automated safety check: Pass	Apache-2.0	today
Minimal Run And Auditlllllllama/RigorPilot-Skills	497	2 repos	~691	Automated safety check: Pass	MIT	14 days ago
Moav E2EMotherofallVPNs/MoaV	448	—	~1.9k	Automated safety check: Notes	MIT	yesterday
Creating A Coral TaskHuman-Agent-Society/CORAL	1k	—	~2.2k	Automated safety check: Pass	Apache-2.0	29 days ago

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Questions about Regression Testing

What does Regression Testing do?

Strategic regression testing with test selection, impact analysis, and continuous regression management. Regression Testing is an agent skill from proffesor-for-testing/agentic-qe. Strategic regression testing with test selection, impact analysis, and continuous regression management.

When should I use Regression Testing?

Regression Testing fits situations like: verifying fixes dont break existing functionality; planning regression suites; optimizing test execution for faster feedback.

How do I install Regression Testing in Claude Code?

Run `npx skills add proffesor-for-testing/agentic-qe --skill regression-testing -a claude-code`. Or copy the skill folder (assets/skills/regression-testing in proffesor-for-testing/agentic-qe) into .claude/skills/regression-testing in your project. Claude Code loads it when a task matches its description.

How do I install Regression Testing in Codex?

Run `npx skills add proffesor-for-testing/agentic-qe --skill regression-testing -a codex`. Or copy the skill folder (assets/skills/regression-testing in proffesor-for-testing/agentic-qe) into .agents/skills/regression-testing in your project. Codex loads it when a task matches its description.

Can I use Regression 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 proffesor-for-testing/agentic-qe --skill regression-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/regression-testing, .gemini/skills/regression-testing, .github/skills/regression-testing and .opencode/skills/regression-testing in your project.

What does Regression Testing need to run?

SKILL.md names no scripts, command-line tools or credentials: Regression Testing is instructions for the agent only.

Does Regression Testing access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Regression 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. The check reads SKILL.md only: the scripts in the folder are not scanned, so read them before running anything.

What licence does Regression Testing use?

Regression 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 Regression Testing use?

About 1.5k tokens (SKILL.md is roughly 6k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Regression Testing?

Skills that share tags, products or a category with Regression Testing: Reproduce Chat States (different-ai/openwork, 24k stars), Dynamo Jira Ticket (DynamoDS/Dynamo, 2k stars), Minimal Run And Audit (lllllllama/RigorPilot-Skills, 497 stars) and Moav E2E (MotherofallVPNs/MoaV, 448 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Regression Testing?

proffesor-for-testing (a GitHub user) maintains it in proffesor-for-testing/agentic-qe, which has 494 GitHub stars. The repository holds 111 skills in this directory. The repository was last updated on October 4, 2026.

Source: proffesor-for-testing/agentic-qe on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Regression Testing

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Regression Testing

Quick Reference Card

When to Use

Test Selection Strategies

Change-Based Test Selection

CI/CD Integration

Agent-Driven Regression

Agent Coordination Hints

Memory Namespace

Fleet Coordination

Related Skills

Remember

Skill Composition

Gotchas

Files

Compare with similar skills

Similar skills

More from proffesor-for-testing/agentic-qe

Related

Questions about Regression Testing