Home / kevmoo / dash_skills · GitHub

dart-matcher-best-practices SKILL.md skillA

dart-matcher-best-practices from kevmoo/dash_skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned

mdr add kevmoo/dash_skills/dart-matcher-best-practices@git:20260913.6c39005

Pins git:20260913.6c39005 in mdr.lock. Pin the fingerprint instead.

Audit grade: A, 17 of 17 checks passed
Kind: SKILL.md skill
Repository: kevmoo/dash_skills
Path: skills/dart-matcher-best-practices/SKILL.md
Versions recorded: 6
Latest version: git:20260913.6c39005, committed Sep 13, 2026
First version recorded: Jun 5, 2026
Size: 6,212 bytes
Repository stars: 148
License: Apache-2.0

Best practices for using `expect` and `package:matcher`. Focuses on readable assertions, proper matcher selection, and avoiding common pitfalls.

Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.

What the file says

# Dart Matcher Best Practices

## When to use this skill

Use this skill when:

- Writing assertions using `expect` and `package:matcher`.
- Migrating legacy manual checks to cleaner matchers.
- Debugging confusing test failures.

### When NOT to use (Abstention Guardrails)

Do NOT apply this skill or refactor assertions when:

- **Non-Collection Properties**: The property happens to be named `.length` but
  belongs to a non-collection class (e.g. geometric scalar magnitude on a
  `Vector`, duration on a buffer, or line segment distance). `hasLength(n)`
  expects an `int` on an `Iterable`, `Map`, or `String`.
- **Custom Domain Booleans**: The boolean check tests an arbitrary domain
  property (e.g. `expect(switch.isEnabled, isTrue)`). Do not invent non-existent
  matchers.
- **Alternative Assertion Frameworks**: The package has adopted `package:checks`
  (`check(x)...`). Do not revert `checks` back to `package:matcher`.
- **Already Idiomatic Assertions**: Tests already use declarative matchers
  (`hasLength`, `isEmpty`, `isNotEmpty`, `contains`, `containsPair`, `isA`,
  `throwsA`). Abstain and make zero modifications.

## Discovery
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint

mdr add kevmoo/dash_skills/dart-matcher-best-practices@sha256:2d90fdb3a1ec9abc

The line at the top of this page pins the label git:20260913.6c39005, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.

Badge

[![mdr](https://markdownregistry.com/badge/art_rvlmpc4g2a7iogh7.svg)](https://markdownregistry.com/a/art_rvlmpc4g2a7iogh7)

2 badge image fetches in 30 days. What the badge shows.

Versions

The registry has recorded 6 versions of this file, between Jun 5, 2026 and Sep 13, 2026, about one every 20 days.

version	committed	commit	size	audit
git:20260913.6c39005 latest	2026-09-13	6c39005	6,212 B	A	view · diff
git:20260912.2fb1238	2026-09-12	2fb1238	6,178 B	A	view · diff
git:20260830.bc6506b	2026-08-30	bc6506b	5,289 B	A	view · diff
git:20260629.1219374	2026-06-29	1219374	4,622 B	A	view · diff
git:20260619.114edb8	2026-06-19	114edb8	4,510 B	A	view · diff
git:20260605.fae9871	2026-06-05	fae9871	4,749 B	A	view

Audit of the latest version

A 17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.

pass: Frontmatter block present
pass: Frontmatter declares a name
pass: Frontmatter declares a description
pass: Size between 200 bytes and 200 KB (6212 bytes)
pass: No zero-width or bidi control characters
pass: No instruction hidden inside an HTML comment
pass: No link to an exfiltration or paste host
pass: No credential-shaped string
pass: No instruction to send local credentials anywhere
pass: No text hidden with inline styles
pass: No prompt-injection phrasing
pass: No curl or wget piped into a shell
pass: No recursive delete of root, home or parent
pass: No instruction to read or print local credentials
pass: No base64 blob over 200 characters
pass: No link to a raw IP address
pass: No script tag

Source

GitHub

kevmoo/dash_skills · 148 stars · license Apache-2.0 · pushed 2026-11-03 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_rvlmpc4g2a7iogh7
GET https://markdownregistry.com/api/v1/resolve?ref=kevmoo/dash_skills/dart-matcher-best-practices
GET https://markdownregistry.com/api/v1/blob/2d90fdb3a1ec9abceb50d22520bc213e45c7302bde4dcef55cda8b3065da6855

Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.

Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.

More from kevmoo/dash_skills

dart-best-practices SKILL.md skill

kevmoo/dash_skills · skills/dart-best-practices/SKILL.md · General best practices for Dart development. Covers code style, effective Dart, and language features.