Make more use of JS arrow functions. NFC (emscripten-core#19218)

Author: sbc100

src/IDBStore.js

@@ -28,7 +28,7 @@
     } catch (e) {
       return callback(e);
     }
-    req.onupgradeneeded = function(e) {
+    req.onupgradeneeded = (e) => {
       var db = /** @type {IDBDatabase} */ (e.target.result);
       var transaction = e.target.transaction;
       var fileStore;
@@ -38,24 +38,24 @@
         fileStore = db.createObjectStore(IDBStore.DB_STORE_NAME);
       }
     };
-    req.onsuccess = function() {
+    req.onsuccess = () => {
       db = /** @type {IDBDatabase} */ (req.result);
       // add to the cache
       IDBStore.dbs[name] = db;
       callback(null, db);
     };
-    req.onerror = /** @this{IDBOpenDBRequest} */ function(e) {
-      callback(this.error);
-      e.preventDefault();
+    req.onerror = function(event) {
+      callback(event.target.error || 'unknown error');
+      event.preventDefault();
     };
   },
   getStore: function(dbName, type, callback) {
     IDBStore.getDB(dbName, function(error, db) {
       if (error) return callback(error);
       var transaction = db.transaction([IDBStore.DB_STORE_NAME], type);
-      transaction.onerror = function(e) {
-        callback(this.error || 'unknown error');
-        e.preventDefault();
+      transaction.onerror = (event) => {
+        callback(event.target.error || 'unknown error');
+        event.preventDefault();
       };
       var store = transaction.objectStore(IDBStore.DB_STORE_NAME);
       callback(null, store);
@@ -66,14 +66,14 @@
     IDBStore.getStore(dbName, 'readonly', function(err, store) {
       if (err) return callback(err);
       var req = store.get(id);
-      req.onsuccess = function(event) {
+      req.onsuccess = (event) => {
         var result = event.target.result;
         if (!result) {
           return callback('file ' + id + ' not found');
         }
         return callback(null, result);
       };
-      req.onerror = function(error) {
+      req.onerror = (error) => {
         callback(error);
       };
     });
@@ -82,36 +82,24 @@
     IDBStore.getStore(dbName, 'readwrite', function(err, store) {
       if (err) return callback(err);
       var req = store.put(data, id);
-      req.onsuccess = function(event) {
-        callback();
-      };
-      req.onerror = function(error) {
-        callback(error);
-      };
+      req.onsuccess = (event) => callback();
+      req.onerror = (error) => callback(error);
     });
   },
   deleteFile: function(dbName, id, callback) {
     IDBStore.getStore(dbName, 'readwrite', function(err, store) {
       if (err) return callback(err);
       var req = store.delete(id);
-      req.onsuccess = function(event) {
-        callback();
-      };
-      req.onerror = function(error) {
-        callback(error);
-      };
+      req.onsuccess = (event) => callback();
+      req.onerror = (error) => callback(error);
     });
   },
   existsFile: function(dbName, id, callback) {
     IDBStore.getStore(dbName, 'readonly', function(err, store) {
       if (err) return callback(err);
       var req = store.count(id);
-      req.onsuccess = function(event) {
-        callback(null, event.target.result > 0);
-      };
-      req.onerror = function(error) {
-        callback(error);
-      };
+      req.onsuccess = (event) => callback(null, event.target.result > 0);
+      req.onerror = (error) => callback(error);
     });
   },
 }

src/headless.js

@@ -43,7 +43,7 @@ var window = {
       func: func,
       when: window.fakeNow + (ms || 0)
     });
-    window.timeouts.sort(function(x, y) { return y.when - x.when });
+    window.timeouts.sort((x, y) => { return y.when - x.when });
   },
   runEventLoop: function() {
     // run forever until an exception stops this replay
@@ -101,7 +101,7 @@ var window = {
   callEventListeners: function(id) {
     var listeners = this.eventListeners[id];
     if (listeners) {
-      listeners.forEach(function(listener) { listener() });
+      listeners.forEach((listener) => listener());
     }
   },
   URL: {
@@ -136,12 +136,12 @@ var document = {
       case 'canvas': return document.getElementById(what);
       case 'script': {
         var ret = {};
-        window.setTimeout(function() {
+        window.setTimeout(() => {
           headlessPrint('loading script: ' + ret.src);
           load(ret.src);
           headlessPrint('   script loaded.');
           if (ret.onload) {
-            window.setTimeout(function() {
+            window.setTimeout(() => {
               ret.onload(); // yeah yeah this might vanish
             });
           }
@@ -265,7 +265,7 @@ var Worker = (workerPath) => {
   this.postMessage = (msg) => {
     msg.messageId = Worker.messageId++;
     headlessPrint('main thread sending message ' + msg.messageId + ' to worker ' + workerPath);
-    window.setTimeout(function() {
+    window.setTimeout(() => {
       headlessPrint('worker ' + workerPath + ' receiving message ' + msg.messageId);
       onmessage({ data: duplicateJSON(msg) });
     });
@@ -274,7 +274,7 @@ var Worker = (workerPath) => {
   var postMessage = (msg) => {
     msg.messageId = Worker.messageId++;
     headlessPrint('worker ' + workerPath + ' sending message ' + msg.messageId);
-    window.setTimeout(function() {
+    window.setTimeout(() => {
       headlessPrint('main thread receiving message ' + msg.messageId + ' from ' + workerPath);
       thisWorker.onmessage({ data: duplicateJSON(msg) });
     });

src/library.js

@@ -3174,8 +3174,8 @@ mergeInto(LibraryManager.library, {
     if (!elements) {
       elements = [document, document.getElementById('canvas')];
     }
-    ['keydown', 'mousedown', 'touchstart'].forEach(function(event) {
-      elements.forEach(function(element) {
+    ['keydown', 'mousedown', 'touchstart'].forEach((event) => {
+      elements.forEach((element) => {
         if (element) {
           listenOnce(element, event, () => {
             if (ctx.state === 'suspended') ctx.resume();
@@ -3548,7 +3548,7 @@ mergeInto(LibraryManager.library, {
   $safeSetTimeout__docs: '/** @param {number=} timeout */',
   $safeSetTimeout: function(func, timeout) {
     {{{ runtimeKeepalivePush() }}}
-    return setTimeout(function() {
+    return setTimeout(() => {
       {{{ runtimeKeepalivePop() }}}
       callUserCallback(func);
     }, timeout);

src/library_browser.js

@@ -236,7 +236,7 @@ var LibraryBrowser = {
           };
           audio.src = url;
           // workaround for chrome bug 124926 - we do not always get oncanplaythrough or onerror
-          safeSetTimeout(function() {
+          safeSetTimeout(() => {
             finish(audio); // try to use it even though it is not necessarily ready to play
           }, 10000);
         } else {
@@ -320,7 +320,7 @@ var LibraryBrowser = {
       Browser.init();
 
       var handled = false;
-      Module['preloadPlugins'].forEach(function(plugin) {
+      Module['preloadPlugins'].forEach((plugin) => {
         if (handled) return;
         if (plugin['canHandle'](fullname)) {
           plugin['handle'](byteArray, fullname, finish, onerror);
@@ -376,7 +376,7 @@ var LibraryBrowser = {
         Module.ctx = ctx;
         if (useWebGL) GL.makeContextCurrent(contextHandle);
         Module.useWebGL = useWebGL;
-        Browser.moduleContextCreatedCallbacks.forEach(function(callback) { callback() });
+        Browser.moduleContextCreatedCallbacks.forEach((callback) => callback());
         Browser.init();
       }
       return ctx;
@@ -465,7 +465,7 @@ var LibraryBrowser = {
                 document['mozCancelFullScreen'] ||
                 document['msExitFullscreen'] ||
                 document['webkitCancelFullScreen'] ||
-          (function() {});
+          (() => {});
       CFS.apply(document, []);
       return true;
     },
@@ -515,7 +515,7 @@ var LibraryBrowser = {
     },
     safeRequestAnimationFrame: function(func) {
       {{{ runtimeKeepalivePush() }}}
-      return Browser.requestAnimationFrame(function() {
+      return Browser.requestAnimationFrame(() => {
         {{{ runtimeKeepalivePop() }}}
         callUserCallback(func);
       });
@@ -695,9 +695,7 @@ var LibraryBrowser = {
 
     updateResizeListeners: function() {
       var canvas = Module['canvas'];
-      Browser.resizeListeners.forEach(function(listener) {
-        listener(canvas.width, canvas.height);
-      });
+      Browser.resizeListeners.forEach((listener) => listener(canvas.width, canvas.height));
     },
 
     setCanvasSize: function(width, height, noUpdates) {

src/library_dylink.js

@@ -301,7 +301,7 @@ var LibraryDylink = {
 #if DYLINK_DEBUG
     dbg('dlSetError: ' + msg);
 #endif
-    withStackSave(function() {
+    withStackSave(() => {
       var cmsg = stringToUTF8OnStack(msg);
       ___dl_seterr(cmsg, 0);
     });
@@ -807,9 +807,9 @@ var LibraryDylink = {
           var instance = new WebAssembly.Instance(binary, info);
           return Promise.resolve(postInstantiation(instance));
         }
-        return WebAssembly.instantiate(binary, info).then(function(result) {
-          return postInstantiation(result.instance);
-        });
+        return WebAssembly.instantiate(binary, info).then(
+          (result) => postInstantiation(result.instance)
+        );
       }
 
       var module = binary instanceof WebAssembly.Module ? binary : new WebAssembly.Module(binary);
@@ -819,18 +819,14 @@ var LibraryDylink = {
 
     // now load needed libraries and the module itself.
     if (flags.loadAsync) {
-      return metadata.neededDynlibs.reduce(function(chain, dynNeeded) {
-        return chain.then(function() {
+      return metadata.neededDynlibs.reduce((chain, dynNeeded) => {
+        return chain.then(() => {
           return loadDynamicLibrary(dynNeeded, flags);
         });
-      }, Promise.resolve()).then(function() {
-        return loadModule();
-      });
+      }, Promise.resolve()).then(loadModule);
     }
 
-    metadata.neededDynlibs.forEach(function(dynNeeded) {
-      loadDynamicLibrary(dynNeeded, flags, localScope);
-    });
+    metadata.neededDynlibs.forEach((needed) => loadDynamicLibrary(needed, flags, localScope));
     return loadModule();
   },
 
@@ -1015,11 +1011,11 @@ var LibraryDylink = {
 
     // Load binaries asynchronously
     addRunDependency('loadDylibs');
-    dynamicLibraries.reduce(function(chain, lib) {
-      return chain.then(function() {
+    dynamicLibraries.reduce((chain, lib) => {
+      return chain.then(() => {
         return loadDynamicLibrary(lib, {loadAsync: true, global: true, nodelete: true, allowUndefined: true});
       });
-    }, Promise.resolve()).then(function() {
+    }, Promise.resolve()).then(() => {
       // we got them all, wonderful
       reportUndefinedSymbols();
       removeRunDependency('loadDylibs');
@@ -1093,13 +1089,13 @@ var LibraryDylink = {
 #endif
   _dlopen_js: function(handle) {
 #if ASYNCIFY
-    return Asyncify.handleSleep(function(wakeUp) {
+    return Asyncify.handleSleep((wakeUp) => {
       var jsflags = {
         loadAsync: true,
         fs: FS, // load libraries from provided filesystem
       }
       var promise = dlopenInternal(handle, jsflags);
-      promise.then(wakeUp).catch(function() { wakeUp(0) });
+      promise.then(wakeUp).catch(() => wakeUp(0));
     });
 #else
     var jsflags = {
@@ -1118,11 +1114,11 @@ var LibraryDylink = {
       var filename = UTF8ToString({{{ makeGetValue('handle', C_STRUCTS.dso.name, '*') }}});
       dlSetError('Could not load dynamic lib: ' + filename + '\n' + e);
       {{{ runtimeKeepalivePop() }}}
-      callUserCallback(function () { {{{ makeDynCall('vpp', 'onerror') }}}(handle, user_data); });
+      callUserCallback(() => {{{ makeDynCall('vpp', 'onerror') }}}(handle, user_data));
     }
     function successCallback() {
       {{{ runtimeKeepalivePop() }}}
-      callUserCallback(function () { {{{ makeDynCall('vpp', 'onsuccess') }}}(handle, user_data); });
+      callUserCallback(() => {{{ makeDynCall('vpp', 'onsuccess') }}}(handle, user_data));
     }
 
     {{{ runtimeKeepalivePush() }}}

src/library_html5_webgl.js

@@ -404,7 +404,7 @@ var LibraryHtml5WebGL = {
     if (!target) target = Module['canvas'];
 #endif
 
-    var webGlEventHandlerFunc = function(e = event) {
+    var webGlEventHandlerFunc = (e = event) => {
 #if PTHREADS
       if (targetThread) JSEvents.queueEventHandlerOnThread_iiii(targetThread, callbackfunc, eventTypeId, 0, userData);
       else

src/library_lz4.js

@@ -57,9 +57,7 @@ mergeInto(LibraryManager.library, {
             if (plugin['canHandle'](fullname)) {
               var dep = getUniqueRunDependency('fp ' + fullname);
               addRunDependency(dep);
-              var finish = function() {
-                removeRunDependency(dep);
-              }
+              var finish = () => removeRunDependency(dep);
               var byteArray = FS.readFile(fullname);
               plugin['handle'](byteArray, fullname, finish, finish);
               handled = true;

src/library_openal.js

@@ -545,7 +545,7 @@ var LibraryOpenAL = {
         var lUpY = listener.up[1];
         var lUpZ = listener.up[2];
 
-        var inverseMagnitude = function(x, y, z) {
+        var inverseMagnitude = (x, y, z) => {
           var length = Math.sqrt(x * x + y * y + z * z);
 
           if (length < Number.EPSILON) {
@@ -1765,13 +1765,13 @@ var LibraryOpenAL = {
 
     // Preparing for getUserMedia()
 
-    var onError = function(mediaStreamError) {
+    var onError = (mediaStreamError) => {
       newCapture.mediaStreamError = mediaStreamError;
 #if OPENAL_DEBUG
       dbg('navigator.getUserMedia() errored with: ' + mediaStreamError);
 #endif
     };
-    var onSuccess = function(mediaStream) {
+    var onSuccess = (mediaStream) => {
       newCapture.mediaStreamSourceNode = newCapture.audioCtx.createMediaStreamSource(mediaStream);
       newCapture.mediaStream = mediaStream;
 
@@ -1819,8 +1819,7 @@ var LibraryOpenAL = {
 
       newCapture.scriptProcessorNode.connect(newCapture.audioCtx.destination);
 
-      newCapture.scriptProcessorNode.onaudioprocess = function(audioProcessingEvent) {
-
+      newCapture.scriptProcessorNode.onaudioprocess = (audioProcessingEvent) => {
         if (!newCapture.isCapturing) {
           return;
         }