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GitHub Username
Validation
Validates a GitHub username per GitHub's documented rules.
/^[a-zA-Z0-9](?:[a-zA-Z0-9]|-(?=[a-zA-Z0-9])){0,38}$/How it works
GitHub usernames are 1–39 characters, alphanumeric or hyphen, cannot start or end with a hyphen, and cannot have consecutive hyphens. The lookahead enforces no trailing or doubled hyphens.
Test Cases
Should Match
- torvalds
- octocat
- a-b-c
- User1
Should NOT Match
- -leading
- trailing-
- double--hyphen
Quick Summary
Validates a GitHub username (1–39 chars, alphanumeric or single hyphens, no leading/trailing hyphen).