merge gh actions from master

.github/workflows/js.yml

@@ -0,0 +1,24 @@
+name: Node.js CI
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [8.x, 10.x, 12.x]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: npm install
+    - run: npm run build --if-present
+    - run: npm test
+      env:
+        CI: true

.travis.yml

@@ -1,5 +0,0 @@
-language: node_js
-node_js:
-  - 11
-after_script:
-  - npm run build -- retire

js/reveal.js

@@ -32,8 +32,12 @@
 		HORIZONTAL_SLIDES_SELECTOR = '.slides>section',
 		VERTICAL_SLIDES_SELECTOR = '.slides>section.present>section',
 		HOME_SLIDE_SELECTOR = '.slides>section:first-of-type',
+
 		UA = navigator.userAgent,
 
+		// Methods that may not be invoked via the postMessage API
+		POST_MESSAGE_METHOD_BLACKLIST = /registerPlugin|registerKeyboardShortcut|addKeyBinding|addEventListener/,
+
 		// Configuration defaults, can be overridden at initialization time
 		config = {
 
@@ -1311,11 +1315,20 @@
 
 					// Check if the requested method can be found
 					if( data.method && typeof Reveal[data.method] === 'function' ) {
-						var result = Reveal[data.method].apply( Reveal, data.args );
 
-						// Dispatch a postMessage event with the returned value from
+						if( POST_MESSAGE_METHOD_BLACKLIST.test( data.method ) === false ) {
-						// our method invocation for getter functions
+
-						dispatchPostMessage( 'callback', { method: data.method, result: result } );
+							var result = Reveal[data.method].apply( Reveal, data.args );
+
+							// Dispatch a postMessage event with the returned value from
+							// our method invocation for getter functions
+							dispatchPostMessage( 'callback', { method: data.method, result: result } );
+
+						}
+						else {
+							console.warn( 'reveal.js: "'+ data.method +'" is is blacklisted from the postMessage API' );
+						}
+
 					}
 				}
 			}, false );