require-return-from-computed.md

ember/require-return-from-computed

💼 This rule is enabled in the ✅ recommended config.

Always return a value from a computed property function.

Note that this rule applies only to computed properties in classic classes (i.e. Component.extend({})) and not in native JavaScript classes with decorators. ESLint already has two recommended rules getter-return and no-setter-return that enforce the correct behavior with native classes.

Examples

Examples of incorrect code for this rule:

/* eslint "consistent-return": "off" */
import Component from '@ember/component';
import { computed } from '@ember/object';

export default Component.extend({
  firstName: null,
  lastName: null,

  fullName: computed('firstName', 'lastName', {
    get() {
      return `${this.firstName} ${this.lastName}`;
    },
    set(key, value) {
      const [firstName, lastName] = value.split(/\s+/);
      this.set('firstName', firstName);
      this.set('lastName', lastName);
      // Missing return here.
    }
  }),

  salutation: computed('firstName', function () {
    if (this.firstName) {
      return `Dr. ${this.firstName}`;
    }
    // Missing return here.
  })
});

Examples of correct code for this rule:

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

export default Component.extend({
  firstName: null,
  lastName: null,

  fullName: computed('firstName', 'lastName', {
    get() {
      return `${this.firstName} ${this.lastName}`;
    },
    set(key, value) {
      const [firstName, lastName] = value.split(/\s+/);
      this.set('firstName', firstName);
      this.set('lastName', lastName);
      return value;
    }
  }),

  salutation: computed('firstName', function () {
    if (this.firstName) {
      return `Dr. ${this.firstName}`;
    }
    return '';
  })
});

Migration

To avoid false positives from relying on implicit returns in some code branches, you may want to enforce consistent-return alongside this rule.

Related Rules

• consistent-return from eslint
• getter-return from eslint
• no-setter-return from eslint