no-unused-vars

Detects unused variables, imports and functions.

Rule details

This rule will warn you about:

• Unused local variables or parameters.
• Unused named imports.
• Unused private state variables.
• Unused private functions.

This rule will not warn you about:

• Unused public, external or internal functions.
• Unused public or internal state variables.
• Unused global imports.
• Unused named return parameters.

Examples of incorrect code for this rule:

import { UnusedNamedImport } from "./Unused.sol";

contract Example {
  uint private unusedPrivateStateVar;

  function unusedPrivateFunction(uint unusedParam) private {
    uint unusedLocalVar;
  }
}

Examples of correct code for this rule:

import "./UnusedGlobalImport.sol";

contract Example {
  uint public unusedPublicStateVar;

  function unusedPublicFunction() public view returns (uint unusedReturnParam) {
    return 1;
  }
}

Options

This rule can receive an object option with an ignorePattern string field, which is a regular expression that matches identifiers to ignore.

For example, to ignore all identifiers that start with an underscore, you can do:

"no-unused-vars": [
  "error",
  {
    "ignorePattern": "^_"
  }
]