Feature/web lock leader election (#1137)

* ADD use web lock api if possible

* FIX cleanup

* FIX stuff

* FIx

* FIX export

* FIX stuff

* FIX ci

* FIX homepage

* FIX

* FIx

* REFACTOR hasLeader()

* FIX tests

.github/README.md

@@ -201,6 +201,9 @@ Depending in which environment this is used, a proper method is automatically se
 This module also comes with a leader-election which can be used to elect a leader between different BroadcastChannels.
 For example if you have a stable connection from the frontend to your server, you can use the LeaderElection to save server-side performance by only connecting once, even if the user has opened your website in multiple tabs.
 
+In the background it will use the [Web Locks API](https://developer.mozilla.org/en-US/docs/Web/API/Web_Locks_API) if possible and fall back to a message-based election algorithm if WebLocks is not available.
+
+
 In this example the leader is marked with the crown ♛:
 ![leader-election.gif](../docs/files/leader-election.gif)
 
@@ -223,14 +226,15 @@ import { createLeaderElection } from 'broadcast-channel';
 const elector = createLeaderElection(channel);
 elector.awaitLeadership().then(()=> {
   console.log('this tab is now leader');
-})
+});
 ```
 
-Check if there is a leader at this point in time. `hasLeader` is true when there is a leader. It becomes false, if the leader is dead. Then it becomes true again when a new leader is elected.
+Check if there is a leader at this point in time. `hasLeader()` returns true when there is a leader. It returns false, if the leader is dead. Then it returns true again when a new leader is elected.
 
 ```js
 const elector = createLeaderElection(channel);
-console.log('leader exists: ' + elector.hasLeader);
+const hasLeader = await elector.hasLeader();
+console.log('leader exists: ' + hasLeader);
 ```
 
 If more than one tab is becoming leader adjust `LeaderElectionOptions` configuration.

.github/workflows/main.yml

@@ -18,7 +18,7 @@ jobs:
   # This workflow contains a single job called "build"
   base:
     # The type of runner that the job will run on
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps:
@@ -86,10 +86,10 @@ jobs:
 
   # run the node test in an own task, so we can use a node-version matrix.
   test-node:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     strategy:
       matrix:
-        node: ['16.13.1', '17.3.0', '18.12.1']
+        node: ['17.3.0', '18.12.1']
     steps:
       - uses: actions/checkout@v3
       - name: Setup Node.js environment

.github/workflows/prevent-commit-to-generated.yml

@@ -5,12 +5,11 @@ on:
   pull_request:
     paths:
     - 'dist/**'
-    - 'docs/**'
 
 jobs:
   warn-user:
     runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v3
       - name: Warn User to not commit generated files
-        run: bash -c 'echo "You have commited generated files (from the dist or docs folder), this is not allowed. You can only commit files that you have manually edited" && exit 1'
+        run: bash -c 'echo "You have commited generated files (from the dist folder), this is not allowed. You can only commit files that you have manually edited" && exit 1'

CHANGELOG.md

@@ -3,6 +3,9 @@
 
 ## X.X.X (comming soon)
 
+- Use [Web Locks API](https://developer.mozilla.org/en-US/docs/Web/API/Web_Locks_API) for leader election if possible.
+- `LeaderElector.hasLeader` is now a function that returns a `Promise<boolean>`.
+
 ## 4.20.1 (6 January 2023)
 
 - FIX exports order

config/karma.conf.js

@@ -26,11 +26,7 @@ const configuration = {
             console.log('availableBrowser:');
             console.dir(availableBrowser);
             const browsers = availableBrowser
-                .filter(b => !['PhantomJS', 'FirefoxAurora', 'FirefoxNightly'].includes(b))
-                .map(b => {
-                    if (process.env.TRAVIS && b === 'Chrome') return 'Chrome_travis_ci';
-                    else return b;
-                });
+                .filter(b => !['PhantomJS', 'FirefoxAurora', 'FirefoxNightly'].includes(b));
             return browsers;
         }
     },
@@ -58,10 +54,9 @@ const configuration = {
     envPreprocessor: [
         'GITHUB_ACTIONS',
     ],
-
     client: {
         mocha: {
-            bail: false,
+            bail: true,
             timeout: 12000
         },
         captureConsole: true
@@ -75,14 +70,10 @@ const configuration = {
             flags: ['--no-sandbox']
         }
     },
-    singleRun: true
+    singleRun: true,
+    concurrency: 1
 };
 
-if (process.env.TRAVIS) {
-    configuration.browsers = ['Chrome_travis_ci'];
-    configuration.concurrency = 1;
-}
-
 module.exports = function (config) {
     config.set(configuration);
 };