matches-prop-shorthand.md

Matches property shorthand

When using certain methods in Lodash such as filter, it is possible to use the _.matchesProperty callback shorthand. This rule will enforce whether or not to use shorthand when possible to keep consistency in your code.

Rule Details

This rule takes two arguments.

• The first is when to use the code: always or never (default is always).

• The second is an object with one possible property - onlyLiterals (default to false). This exists because changing to a matches will do a deep comparison rather than an instance equality check, so in some circumstances the rule could error on a line that if changed would change behaviour. However, switching on onlyLiterals will not warn on comparing with variables since it is difficult to determine the possible types of variables used.

The following patterns are considered warnings:

/* eslint lodash/matches-prop-shorthand: [2, "always"] */
var result = _.filter(users, function (i) { return i.id === 3; });

/* eslint lodash/matches-prop-shorthand: [2, "never"] */
var result = _.filter(users, ['id', 3]);

The following patterns are not considered warnings:

/* eslint lodash/matches-prop-shorthand: [2, "always"] */
var result = _.filter(users, ['id', 3]);

/* eslint lodash/matches-prop-shorthand: [2, "never"] */
var result = _.filter(users, function (i) { return i.id === 3; });

/* eslint lodash/matches-prop-shorthand: [2, "always", { onlyLiterals: true }] */
var result = _.filter(users, function (i) { return i.id === id; });

When Not To Use It

If you do not want to enforce whether or not to use _.matchesProperty callback shorthand, then you can disable this rule.