Slippy

⚠️ Slippy is now published under the slippy package.

Please see the new documentation site for up-to-date usage and the v0.3.0 release notes for migration instructions.

Slippy is a linter for Solidity that's simple, powerful, and thoughtfully built.

Installation

Install it:

npm install --save-dev @slippy-lint/slippy

Initialize a config file:

npx slippy --init

Run it:

npx slippy "contracts/**/*.sol"

Why Slippy?

You can read a more detailed comparison between Slippy and Solhint, but here's a summary:

• A single, flexible configuration that lets you easily enable or disable rules for specific parts of your codebase
• A unified naming-convention rule
• A more accurate no-unused-vars rule
• Unused comment directives like // slippy-disable-line are reported
• No formatting rules
• Semantic versioning

Configuration

Slippy's configuration lives in a slippy.config.js file, which exports the configuration that Slippy will use to lint your code. Here’s a minimal example:

module.exports = {
  rules: {
    "no-console": "warn",
    "no-unused-vars": ["error", { ignorePattern: "^_" }],
  },
};

For more details on configuring Slippy, including advanced features like cascading configurations, file ignores, and comment directives, see the configuration documentation.

Rules

Rules that have a 🔧 next to them can be automatically fixed by running Slippy with the --fix flag.

• compatible-pragma: checks that the minimum supported pragma version is compatible with the features used in the file.
• curly: enforces the use of curly braces for all control structures.
• explicit-types: enforces or forbids the use of aliases like uint instead of uint256. 🔧
• id-denylist: allows you to specify a list of forbidden identifiers.
• imports-on-top: enforces that all import statements are at the top of the file.
• max-state-vars: limits the number of state variables in a contract.
• named-return-params: enforces that functions with multiple return parameters use named return parameters.
• naming-convention: enforces a naming convention across the codebase.
• no-console: forbids the use of console.log and the import of console.sol.
• no-default-visibility: forbids the use of default visibility for state variables. 🔧
• no-duplicate-imports: forbids importing the same file multiple times.
• no-empty-blocks: forbids blocks without statements.
• no-global-imports: forbids global imports like import "./foo.sol".
• no-restricted-syntax: disallows syntax patterns specified with Slang queries.
• no-send: forbids the use of send and transfer for sending value, in favor of using call with value.
• no-tx-origin: forbids the use of tx.origin.
• no-unchecked-calls: disallows low-level calls like call, staticcall, and delegatecall that don't use their return values.
• no-uninitialized-immutable-references: forbids using immutable references before they are initialized.
• no-unused-vars: detects unused variables, imports and functions.
• one-contract-per-file: enforces that a file contains at most one contract/interface/library definition.
• private-vars: enforces that all state variables are private.
• require-revert-reason: enforces that all reverts have a reason.
• sort-imports: enforces a specific order for import statements.
• sort-members: enforces a specific order for top-level elements and contract/interface/library members.
• sort-modifiers: enforces a specific order for modifiers.
• yul-prefer-iszero: recommends using iszero instead of eq when comparing to the 0 literal in Yul code.

Don't see a rule you need? Open an issue.