Interface file naming

Severity: Info ID: interface-file-naming

Flags Solidity files whose only top-level declaration is an interface but whose filename is not prefixed with I.

What it does

Reports interface-only files whose path basename does not start with I (e.g. IERC20.sol).

Why is this bad?

Prefixing interface filenames with I is the prevailing convention in the Solidity ecosystem. Following it makes import paths predictable and lets reviewers tell at a glance whether they are looking at an interface or an implementation.

Example

Bad

contracts/Token.sol      // file contains only `interface Token { ... }`

Good

contracts/IToken.sol     // file contains only `interface IToken { ... }`