Eslint-plugin-underscore NPM

ESLint-plugin-underscore

Linting rules for Underscore

Installation

Install ESLint either locally or globally.

npm install eslint

If you installed ESLint globally, you have to install the Underscore plugin globally too. Otherwise, install it locally.

$ npm install eslint-plugin-underscore

Configuration

Add plugins section and specify ESLint-plugin-underscore as a plugin.

{
  "plugins": ["underscore"]
}

Finally, enable all of the rules that you would like to use.

{
  "rules": {
    "underscore/collection-return": 2,
    "underscore/identity-shorthand": [2, "always"],
    "underscore/jquery-each": [2, "never"],
    "underscore/jquery-extend": [2, "never"],
    "underscore/jquery-proxy": [2, "never"],
    "underscore/matches-shorthand": [2, "always"],
    "underscore/no-return-value-from-each-iteratee": 2,
    "underscore/no-unnecessary-bind": 2,
    "underscore/prefer-chain": [2, 3],
    "underscore/prefer-compact": 2,
    "underscore/prefer-constant": 2,
    "underscore/prefer-filter": 2,
    "underscore/prefer-findwhere": 2,
    "underscore/prefer-invoke": 2,
    "underscore/prefer-map": 2,
    "underscore/prefer-matches": 2,
    "underscore/prefer-noop": 2,
    "underscore/prefer-pluck": 2,
    "underscore/prefer-reject": 2,
    "underscore/prefer-times": 2,
    "underscore/prefer-underscore-method": 2,
    "underscore/prefer-underscore-typecheck": 2,
    "underscore/prefer-where": 2,
    "underscore/preferred-alias": 2,
    "underscore/prop-shorthand": [2, "always"],

    // The below rules are not (yet) supported
    "underscore/no-single-chain": 2,
    "underscore/unwrap": 2,
    "underscore/no-double-unwrap": 2,
    "underscore/prefer-wrapper-method": 2,
    "underscore/prefer-lodash-chain": 2,
    "underscore/chain-style": [2, "as-needed"]
  }
}

List of supported rules

collection-return: Always return a value in iteratees of Underscore collection methods that aren't each.
identity-shorthand: Prefer identity shorthand syntax.
jquery-each: Standardize on either Underscore's or jQuery's each function.
jquery-extend: Standardize on either Underscore's or jQuery's extend function.
jquery-proxy: Standardize on either Underscore's bind or jQuery's proxy function.
matches-shorthand: Prefer matches shorthand syntax.
no-return-value-from-each-iteratee: Do not return a value from the iteratee of _.each.
no-unnecessary-bind: Prefer passing thisArg over binding.
prefer-chain: Prefer chain over nested Underscore calls.
prefer-compact: Prefer _.compact over _.filter for only truthy values.
prefer-constant: Prefer _.constant over functions returning literals.
prefer-filter: Prefer _.filter over _.each with an if statement inside.
prefer-findwhere: Prefer _.findWhere over _.find when using matcher shorthand. (fixable)
prefer-invoke: Prefer using _.invoke over _.map with a method call inside.
prefer-map: Prefer _.map over _.each with a push inside.
prefer-matches: Prefer _.matches over conditions like a.foo === 1 && a.bar === 2 && a.baz === 3.
prefer-noop: Prefer _.noop over empty functions.
prefer-pluck: Prefer _.pluck over _.map when using property shorthand. (fixable)
prefer-reject: Prefer _.reject over filter with !(expression) or x.prop1 !== value.
prefer-times: Prefer _.times over _.map without using the iteratee's arguments.
prefer-underscore-method: Prefer using Underscore collection methods (e.g. _.map) over native array methods.
prefer-underscore-typecheck: Prefer using _.is* methods over typeof and instanceof checks when applicable.
prefer-where: Prefer _.where over _.filter when using matcher shorthand. (fixable)
preferred-alias: Preferred aliases.
prop-shorthand: Prefer property shorthand syntax. (fixable)

List of Lodash rules which are not yet supported

no-single-chain: Prevent chaining syntax for single method, e.g. _(x).map().value().
unwrap: Prevent chaining without evaluation via value() or non-chainable methods like max().
no-double-unwrap: Do not use .value() on chains that have already ended (e.g. with max() or reduce()).
prefer-wrapper-method: Prefer using array and string methods in the chain and not the initial value, e.g. _(str).split(' ')...
prefer-lodash-chain: Prefer using Lodash chains (e.g. _.map) over native and mixed chains.
chain-style: Enforce a specific chain style: explicit, implicit, or explicit only when necessary.