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.
npx skills add summarybotng/summarybot-ng --skill shift-left-testinggit clone --depth 1 https://github.com/summarybotng/summarybot-ngWrote 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/skills/summarybotng/summarybot-ng/shift-left-testing)<a href="https://agentmods.dev/skills/summarybotng/summarybot-ng/shift-left-testing"><img src="https://agentmods.dev/badge/skills/summarybotng/summarybot-ng/shift-left-testing/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/skills/summarybotng/summarybot-ng/shift-left-testing"><img src="https://agentmods.dev/badge/skills/summarybotng/summarybot-ng/shift-left-testing.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 | $0.00035 | $0.01587 |
| Opus 5 | $0.00017 | $0.00794 |
| Sonnet 5 | $0.00007 | $0.00317 |
| Haiku 4.5 | $0.00003 | $0.00159 |
Grade A, and why
shift-left-testing 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 5d 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.
How it starts
The opening of the file, as written. The whole thing — 232 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Shift-Left Testing
<default_to_action> When implementing early testing practices:
- VALIDATE requirements before coding (testability, BDD scenarios)
- WRITE tests before implementation (TDD red-green-refactor)
- AUTOMATE in CI pipeline (every commit triggers tests)
- FOLLOW test pyramid: Many unit (70%), some integration (20%), few E2E (10%)
- FIX defects immediately - never let them accumulate
Quick Shift-Left Levels:
- Level 1: Unit tests with each PR (developer responsibility)
- Level 2: TDD practice (tests before code)
- Level 3: BDD/Example mapping in refinement (requirements testing)
- Level 4: Risk analysis in design (architecture testing)
Critical Success Factors:
- Defects found in requirements cost 1x; in production cost 100x
- Every commit must run automated tests
- Quality is built in, not tested in </default_to_action>
Quick Reference Card
When to Use
- Reducing cost of defects
- Implementing CI/CD pipelines
- Starting TDD practice
- Improving requirements quality
Cost of Defects by Phase
| Phase | Relative Cost | Example |
|---|---|---|
| Requirements | 1x | Fix doc: 30 min |
| Design | 5x | Redesign: few hours |
| Development | 10x | Code fix: 1 day |
| Testing | 20x | Fix + retest: 2 days |
| Production | 100x | Hotfix + rollback + investigation |
Test Pyramid
/\ E2E (10%) - Critical user journeys
/ \
/ \ Integration (20%) - Component interactions
/ \
/________\ Unit (70%) - Fast, isolated, comprehensive
Shift-Left Levels
| Level | Practice | When |
|---|---|---|
| 1 | Unit tests in PR | Before merge |
| 2 | TDD | Before implementation |
| 3 | BDD/Example Mapping | During refinement |
| 4 | Risk Analysis | During design |
Level 1: Tests in Every PR
# CI pipeline - tests run on every commit
name: CI
on: [push, pull_request]
jobs:
test:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- run: npm ci
- run: npm run test:unit
- run: npm run test:integration
- run: npm run lint
quality-gate:
needs: test
steps:
- name: Coverage Check
run: npx coverage-check --min 80
- name: No New Warnings
run: npm run lint -- --max-warnings 0
What ships with it
3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 5d ago First seen · 232 lines · 35 tokens per session scan A e716a9caf2c7
shift-left-testing is a skill published in the GitHub repository summarybotng/summarybot-ng (2 stars, last pushed 3mo ago), licensed MIT. It adds 35 tokens to every session and 1,587 once invoked, about $0.0002 per session on Opus 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.
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