How do I install the Assertion Quality Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/assertion-quality/SKILL.md and restart Claude Code. Both flows are detailed at https://claudskills.com/install/.

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

ClaudSkills / Engineering / testing

Assertion Quality

Category: Engineering · Sub-category: testing · Last updated: 2026-05-24

type:audit

Analyzes the variety and depth of assertions across .NET test suites. Use when the user asks to evaluate assertion quality, find shallow testing, identify assertion-free tests (no assertions or only trivial ones like Assert.IsNotNull), flag self-referential or tautological assertions (output equals input on identity/round-trip operations), measure assertion coverage diversity, or audit whether tests verify different facets of correctness. Produces metrics and actionable recommendations. Works with MSTest, xUnit, NUnit, TUnit. DO NOT USE FOR: writing new tests (use writing-mstest-tests), other anti-patterns like flakiness or duplication (use test-anti-patterns), or fixing assertions.

From the source SKILL.md

Analyze .NET test code to measure how varied and meaningful the assertions are. Produce a metrics report that reveals whether tests verify different facets of correctness — not just "output equals X" but also structure, exceptions, state transitions, side effects, and invariants.

What this skill does

Assertion Quality is a community-contributed Claude Code skill in the testing sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/assertion-quality/ and loads when your prompt matches the skill's trigger.

When to invoke it: Use when the user asks to evaluate assertion quality, find shallow testing, identify assertion-free tests (no assertions or only trivial ones like Assert.IsNotNull), flag self-referential or tautological assertions (output equals input on identity/round-trip operations), measure assertion coverage diversity, or audit whether tests verify different facets of correctness.

Who uses this skill

The Assertion Quality Claude Code skill is built for software engineers, backend developers, full-stack teams, and technical leads building and maintaining production systems. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 70,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/assertion-quality
curl -L https://claudskills.com/skills/assertion-quality/SKILL.md \
  -o ~/.claude/skills/assertion-quality/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/assertion-quality/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/assertion-quality/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\assertion-quality\SKILL.md on Windows. See the full install guide for step-by-step instructions.

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Attribution & license

Source: https://github.com/dotnet/skills/blob/HEAD/plugins/dotnet-test/skills/assertion-quality/SKILL.md
License: MIT
Author: dotnet

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

dotnet. (2026). Assertion Quality [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/assertion-quality/

BibTeX

@misc{assertion-quality-2026,
  author    = {dotnet},
  title     = {Assertion Quality [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/assertion-quality/}
}

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