code-duplication SKILL.md skillA
code-duplication from amey-thakur/ai-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add amey-thakur/ai-skills/code-duplication@git:20260718.7c1285cPins git:20260718.7c1285c in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- amey-thakur/ai-skills
- Path
skills/code-quality/code-duplication/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260718.7c1285c, committed Jul 18, 2026
- Size
- 2,926 bytes
- Repository stars
- 14
- License
- MIT
Decide when repeated code should be unified and when a duplicate is the cheaper choice. Use when tempted to extract a shared helper or facing copy-pasted code.
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
# Code duplication Not all repetition is duplication. Two blocks that look alike but change for different reasons are a coincidence, and unifying them couples things that should move apart. The costly mistake is the wrong abstraction: it is harder to back out of than the duplication it replaced. ## Method 1. **Wait for the rule of three.** Two copies are cheap to keep in sync by hand; extract on the third appearance, when the pattern and its variation points are clear. Abstracting from two examples guesses at the shape and usually guesses wrong. 2. **Unify by reason to change, not by appearance.** Ask whether the copies must always change together. A tax calculation shared across invoices and receipts that must stay identical is real duplication; two validators that happen to share four lines today are not. Same shape, different reasons: leave them. 3. **Extract the stable core, parameterize the difference.** When you do unify, the shared function holds what is truly common and takes the varying parts as arguments. If the parameter list balloons with flags that switch behavior, the cases were less alike than they looked; stop. …
Read the whole file at its exact version.
How to install
mdr add amey-thakur/ai-skills/code-duplication@sha256:b1fdaf55de5b9d6bThe line at the top of this page pins the label git:20260718.7c1285c, 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_qjc75fnlh6unlho7)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Jul 18, 2026.
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 (2926 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
amey-thakur/ai-skills · 14 stars · license MIT · pushed 2026-09-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_qjc75fnlh6unlho7 GET https://markdownregistry.com/api/v1/resolve?ref=amey-thakur/ai-skills/code-duplication GET https://markdownregistry.com/api/v1/blob/b1fdaf55de5b9d6b05f5a8f51dbc0c4506ce64dbadca5a9990511ecb9a6dc602
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.