testability-obstacle SKILL.md skillA
testability-obstacle from dotnet/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add dotnet/skills/testability-obstacle@git:20261008.a51399bPins git:20261008.a51399b in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- dotnet/skills
- Path
plugins/dotnet-test/skills/testability-obstacle/SKILL.md- Versions recorded
- 7
- Latest version
- git:20261008.a51399b, committed Oct 8, 2026
- First version recorded
- Aug 27, 2026
- Size
- 14,392 bytes
- Repository stars
- 5,836
- License
- MIT
MUST USE for C#/.NET deterministic tests that require the smallest production seam for DateTime/Task.Delay/File/Environment/Guid/Random, static API preservation, nested/parallel overrides, or no real I/O. USE ONLY when the target workspace contains C# source plus a .csproj or .sln. DO NOT USE for audits, bulk migration, code that already has an injectable seam, or an explicit migration to a user-named existing abstraction (migrate-static-to-wrapper). Use instead of general test generation when…
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
# Resolve a Testability Obstacle Introduce the smallest behavior-preserving seam needed to test a specific C# behavior, then add deterministic tests that prove both the behavior and the seam. The production edit is a means to the requested test, not an invitation to redesign adjacent code. ## When to Use - A requested test would otherwise read/write the real filesystem. - Behavior depends on the current time, delay, random value, environment, console, process, or another ambient dependency. - The user explicitly permits or requests a safe production seam. - Existing tests cannot control a dependency without process-global mutation. ## When Not to Use - The dependency is already injected or passed as an argument. Write tests with a fake through the existing seam using `code-testing`. - The user wants a repository-wide testability audit. Use `detect-static-dependencies`. - The user wants wrappers generated but not call sites/tests changed. Use `generate-testability-wrappers`. - The user requests a broad mechanical migration. Use `migrate-static-to-wrapper`, then generate tests separately. - The user already selected an existing replacement such as `TimeProvider` or …
Read the whole file at its exact version.
How to install
mdr add dotnet/skills/testability-obstacle@sha256:e5edc5a1cf9ed9e5The line at the top of this page pins the label git:20261008.a51399b, 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.
[](https://markdownregistry.com/a/art_7nhtsxqhxngtyanw)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 7 versions of this file, between Aug 27, 2026 and Oct 8, 2026, about one every 7 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261008.a51399b latest | 2026-10-08 | a51399b | 14,392 B | A | view · diff |
| git:20260925.a824bbb | 2026-09-25 | a824bbb | 14,398 B | A | view · diff |
| git:20260908.0afcd3e | 2026-09-08 | 0afcd3e | 15,414 B | A | view · diff |
| git:20260903.30b30ef | 2026-09-03 | 30b30ef | 14,873 B | A | view · diff |
| git:20260902.00b3bac | 2026-09-02 | 00b3bac | 14,217 B | A | view · diff |
| git:20260828.2b9056b | 2026-08-28 | 2b9056b | 13,604 B | A | view · diff |
| git:20260827.0be2ef9 | 2026-08-27 | 0be2ef9 | 12,984 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (14392 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
dotnet/skills · 5,836 stars · license MIT · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_7nhtsxqhxngtyanw GET https://markdownregistry.com/api/v1/resolve?ref=dotnet/skills/testability-obstacle GET https://markdownregistry.com/api/v1/blob/e5edc5a1cf9ed9e56a44133e857349a3a41fed51f2e4162473ae59977e391956
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.