index.md

---

title: permissions.contains()
slug: Mozilla/Add-ons/WebExtensions/API/permissions/contains
page-type: webextension-api-function
tags:
  - API
  - Add-ons
  - Contains
  - Method
  - Permissions
  - Reference
  - WebExtensions
browser-compat: webextensions.api.permissions.contains

---

{{AddonSidebar()}}

Check whether the extension has the permissions listed in the given {{WebExtAPIRef("permissions.Permissions")}} object.

The Permissions argument may contain either an origins property, which is an array of host permissions, or a permissions property, which is an array of API permissions, or both.

This is an asynchronous function that returns a Promise. The promise is fulfilled with true only if all the extension currently has all the given permissions. For host permissions, if the extension's permissions pattern-match the permissions listed in origins, then they are considered to match.

Syntax

let getContains = browser.permissions.contains(
  permissions                // Permissions object
)

Parameters

• permissions

  • : A {{WebExtAPIRef("permissions.Permissions")}} object.

Return value

A Promise that will be fulfilled with true if the extension already has all the permissions listed in the permissions argument, or false otherwise.

Browser compatibility

{{Compat}}

Examples

// Extension permissions are:
// "webRequest", "tabs", "*://*.mozilla.org/*"

let testPermissions1 = {
  origins: ["*://mozilla.org/"],
  permissions: ["tabs"]
};

const testResult1 = await browser.permissions.contains(testPermissions1);
console.log(testResult1); // true

let testPermissions2 = {
  origins: ["*://mozilla.org/"],
  permissions: ["tabs", "alarms"]
};

const testResult2 = await browser.permissions.contains(testPermissions2);
console.log(testResult2); // false, "alarms" doesn't match

let testPermissions3 = {
  origins: ["https://developer.mozilla.org/"],
  permissions: ["tabs", "webRequest"]
};

const testResult3 = await browser.permissions.contains(testPermissions3);
console.log(testResult3); // true: "https://developer.mozilla.org/"
                          // matches: "*://*.mozilla.org/*"

let testPermissions4 = {
  origins: ["https://example.org/"]
};

const testResult4 = await browser.permissions.contains(testPermissions4);
console.log(testResult4); // false, "https://example.org/"
                          // does not match

{{WebExtExamples}}

Note: This API is based on Chromium's chrome.permissions API.