test-discipline

A testing rule that requires tests to change whenever a public API changes. An API is the interface other code uses, while test assertions are the expected results that automated tests compare against.

In plain words
What is it for?
Use it when changing function signatures, exported interfaces, features, documentation counts, or scenario files, and when investigating test failures caused by outdated expectations.
Why use it?
Stale tests can fail after legitimate code changes or miss newly added files and features. Keeping tests and expected file lists aligned helps prevent avoidable continuous-integration failures.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/alonf/mcppythondemo/test-discipline
Any agent
npx skills add alonf/MCPPythonDemo --skill test-discipline
Clone the repo
git clone --depth 1 https://github.com/alonf/MCPPythonDemo

Made for: Claude Code, Codex.

Per session 12 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 416 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00012 $0.00416
Opus 5 $0.00006 $0.00208
Sonnet 5 $0.00002 $0.00083
Haiku 4.5 $0.00001 $0.00042

Measured yesterday against content hash 6bd1b96b2856, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

test-discipline 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 yesterday.

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.

Origin

This is a copy

100% identical to test-discipline — 74 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.squad/templates/skills/test-discipline/SKILL.md · 38 lines

What it actually says

Context

When APIs or public interfaces change, tests must be updated in the same commit. When test assertions reference file counts or expected arrays, they must be kept in sync with disk reality. Stale tests block CI for other contributors.

Patterns

  • API changes → test updates (same commit): If you change a function signature, public interface, or exported API, update the corresponding tests before committing
  • Test assertions → disk reality: When test files contain expected counts (e.g., EXPECTED_FEATURES, EXPECTED_SCENARIOS), they must match the actual files on disk
  • Add files → update assertions: When adding docs pages, features, or any counted resource, update the test assertion array in the same commit
  • CI failures → check assertions first: Before debugging complex failures, verify test assertion arrays match filesystem state

Examples

Correct:

  • Changed auth API signature → updated auth.test.ts in same commit
  • Added distributed-mesh.md to features/ → added 'distributed-mesh' to EXPECTED_FEATURES array
  • Deleted two scenario files → removed entries from EXPECTED_SCENARIOS

Incorrect:

  • Changed spawn parameters → committed without updating casting.test.ts (CI breaks for next person)
  • Added built-in-roles.md → left EXPECTED_FEATURES at old count (PR blocked)
  • Test says "expected 7 files" but disk has 25 (assertion staleness)

Anti-Patterns

  • Committing API changes without test updates ("I'll fix tests later")
  • Treating test assertion arrays as static (they evolve with content)
  • Assuming CI passing means coverage is correct (stale assertions can pass while being wrong)
  • Leaving gaps for other agents to discover
Changes

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.

  1. yesterday First seen · 38 lines · 12 tokens per session scan A 6bd1b96b2856

Subscribe to this mod's changes

test-discipline is a skill published in the GitHub repository alonf/MCPPythonDemo (0 stars, last pushed 4mo ago), licensed MIT. It adds 12 tokens to every session and 416 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to test-discipline, differing in 74 lines, and is treated as a copy.

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