require-computed-macros.md

require-computed-macros

It is preferred to use Ember's computed property macros as opposed to manually writing out logic in a computed property function. Reasons include:

• Conciseness
• Readability
• Reduced chance of typos
• Reduced chance of missing dependencies

Rule Details

This rule requires using Ember's computed property macros when possible.

Examples

Examples of incorrect code for this rule:

import Component from '@ember/component';
import { computed } from '@ember/object';

export default Component.extend({
  propReads: computed('x', function() {
    return this.x;
  }),

  propAnd: computed('x', 'y', function() {
    return this.x && this.y;
  }),

  propOr: computed('x', 'y', function() {
    return this.x || this.y;
  }),

  propGt: computed('x', function() {
    return this.x > 123;
  }),

  propGte: computed('x', function() {
    return this.x >= 123;
  }),

  propLt: computed('x', function() {
    return this.x < 123;
  }),

  propLte: computed('x', function() {
    return this.x <= 123;
  }),

  propNot: computed('x', function() {
    return !this.x;
  }),

  propEqual: computed('x', function() {
    return this.x === 123;
  }),
});

Examples of correct code for this rule:

import Component from '@ember/component';
import { reads, and, or, gt, gte, lt, lte, not, equal } from '@ember/object/computed';

export default Component.extend({
  propReads: reads('x'),

  propAnd: and('x', 'y'),

  propOr: or('x', 'y'),

  propGt: gt('x', 123),

  propGte: gte('x', 123),

  propLt: lt('x', 123),

  propLte: lte('x', 123),

  propNot: not('x'),

  propEqual: equal('x', 123)
});

References

• Guide for computed properties
• Spec for computed property macros