diff --git a/src/Fetch.js b/src/Fetch.js
index c70f235d62464..e34d9574f9b7d 100644
--- a/src/Fetch.js
+++ b/src/Fetch.js
@@ -82,7 +82,7 @@ function fetchDeleteCachedData(db, fetch, onsuccess, onerror) {
 
   var fetch_attr = fetch + {{{ C_STRUCTS.emscripten_fetch_t.__attributes }}};
   var path = HEAPU32[fetch_attr + {{{ C_STRUCTS.emscripten_fetch_attr_t.destinationPath }}} >> 2];
-  if (!path) path = HEAPU32[fetch + {{{ C_STRUCTS.emscripten_fetch_t.url }}} >> 2];
+  path ||= HEAPU32[fetch + {{{ C_STRUCTS.emscripten_fetch_t.url }}} >> 2];
   var pathStr = UTF8ToString(path);
 
   try {
@@ -131,7 +131,7 @@ function fetchLoadCachedData(db, fetch, onsuccess, onerror) {
 
   var fetch_attr = fetch + {{{ C_STRUCTS.emscripten_fetch_t.__attributes }}};
   var path = HEAPU32[fetch_attr + {{{ C_STRUCTS.emscripten_fetch_attr_t.destinationPath }}} >> 2];
-  if (!path) path = HEAPU32[fetch + {{{ C_STRUCTS.emscripten_fetch_t.url }}} >> 2];
+  path ||= HEAPU32[fetch + {{{ C_STRUCTS.emscripten_fetch_t.url }}} >> 2];
   var pathStr = UTF8ToString(path);
 
   try {
@@ -196,7 +196,7 @@ function fetchCacheData(/** @type {IDBDatabase} */ db, fetch, data, onsuccess, o
 
   var fetch_attr = fetch + {{{ C_STRUCTS.emscripten_fetch_t.__attributes }}};
   var destinationPath = HEAPU32[fetch_attr + {{{ C_STRUCTS.emscripten_fetch_attr_t.destinationPath }}} >> 2];
-  if (!destinationPath) destinationPath = HEAPU32[fetch + {{{ C_STRUCTS.emscripten_fetch_t.url }}} >> 2];
+  destinationPath ||= HEAPU32[fetch + {{{ C_STRUCTS.emscripten_fetch_t.url }}} >> 2];
   var destinationPathStr = UTF8ToString(destinationPath);
 
   try {
@@ -246,7 +246,7 @@ function fetchXHR(fetch, onsuccess, onerror, onprogress, onreadystatechange) {
 
   var fetch_attr = fetch + {{{ C_STRUCTS.emscripten_fetch_t.__attributes }}};
   var requestMethod = UTF8ToString(fetch_attr + {{{ C_STRUCTS.emscripten_fetch_attr_t.requestMethod }}});
-  if (!requestMethod) requestMethod = 'GET';
+  requestMethod ||= 'GET';
   var timeoutMsecs = {{{ makeGetValue('fetch_attr', C_STRUCTS.emscripten_fetch_attr_t.timeoutMSecs, 'u32') }}};
   var userName = {{{ makeGetValue('fetch_attr', C_STRUCTS.emscripten_fetch_attr_t.userName, '*') }}};
   var password = {{{ makeGetValue('fetch_attr', C_STRUCTS.emscripten_fetch_attr_t.password, '*') }}};
@@ -352,12 +352,12 @@ function fetchXHR(fetch, onsuccess, onerror, onprogress, onreadystatechange) {
 #if FETCH_DEBUG
       dbg(`fetch: xhr of URL "${xhr.url_}" / responseURL "${xhr.responseURL}" succeeded with status ${xhr.status}`);
 #endif
-      if (onsuccess) onsuccess(fetch, xhr, e);
+      onsuccess?.(fetch, xhr, e);
     } else {
 #if FETCH_DEBUG
       dbg(`fetch: xhr of URL "${xhr.url_}" / responseURL "${xhr.responseURL}" failed with status ${xhr.status}`);
 #endif
-      if (onerror) onerror(fetch, xhr, e);
+      onerror?.(fetch, xhr, e);
     }
   };
   xhr.onerror = (e) => {
@@ -369,7 +369,7 @@ function fetchXHR(fetch, onsuccess, onerror, onprogress, onreadystatechange) {
     dbg(`fetch: xhr of URL "${xhr.url_}" / responseURL "${xhr.responseURL}" finished with error, readyState ${xhr.readyState} and status ${xhr.status}`);
 #endif
     saveResponseAndStatus();
-    if (onerror) onerror(fetch, xhr, e);
+    onerror?.(fetch, xhr, e);
   };
   xhr.ontimeout = (e) => {
     // check if xhr was aborted by user and don't try to call back
@@ -379,7 +379,7 @@ function fetchXHR(fetch, onsuccess, onerror, onprogress, onreadystatechange) {
 #if FETCH_DEBUG
     dbg(`fetch: xhr of URL "${xhr.url_}" / responseURL "${xhr.responseURL}" timed out, readyState ${xhr.readyState} and status ${xhr.status}`);
 #endif
-    if (onerror) onerror(fetch, xhr, e);
+    onerror?.(fetch, xhr, e);
   };
   xhr.onprogress = (e) => {
     // check if xhr was aborted by user and don't try to call back
@@ -408,7 +408,7 @@ function fetchXHR(fetch, onsuccess, onerror, onprogress, onreadystatechange) {
     if (xhr.readyState >= 3 && xhr.status === 0 && e.loaded > 0) xhr.status = 200;
     HEAPU16[fetch + {{{ C_STRUCTS.emscripten_fetch_t.status }}} >> 1] = xhr.status;
     if (xhr.statusText) stringToUTF8(xhr.statusText, fetch + {{{ C_STRUCTS.emscripten_fetch_t.statusText }}}, 64);
-    if (onprogress) onprogress(fetch, xhr, e);
+    onprogress?.(fetch, xhr, e);
     if (ptr) {
       _free(ptr);
     }
@@ -423,7 +423,7 @@ function fetchXHR(fetch, onsuccess, onerror, onprogress, onreadystatechange) {
     if (xhr.readyState >= 2) {
       HEAPU16[fetch + {{{ C_STRUCTS.emscripten_fetch_t.status }}} >> 1] = xhr.status;
     }
-    if (onreadystatechange) onreadystatechange(fetch, xhr, e);
+    onreadystatechange?.(fetch, xhr, e);
   };
 #if FETCH_DEBUG
   dbg(`fetch: xhr.send(data=${data})`);
@@ -434,7 +434,7 @@ function fetchXHR(fetch, onsuccess, onerror, onprogress, onreadystatechange) {
 #if FETCH_DEBUG
     dbg(`fetch: xhr failed with exception: ${e}`);
 #endif
-    if (onerror) onerror(fetch, xhr, e);
+    onerror?.(fetch, xhr, e);
   }
 }
 
@@ -466,14 +466,14 @@ function startFetch(fetch, successcb, errorcb, progresscb, readystatechangecb) {
     {{{ runtimeKeepalivePop() }}}
     doCallback(() => {
       if (onsuccess) {{{ makeDynCall('vp', 'onsuccess') }}}(fetch);
-      else if (successcb) successcb(fetch);
+      else successcb?.(fetch);
     });
   };
 
   var reportProgress = (fetch, xhr, e) => {
     doCallback(() => {
       if (onprogress) {{{ makeDynCall('vp', 'onprogress') }}}(fetch);
-      else if (progresscb) progresscb(fetch);
+      else progresscb?.(fetch);
     });
   };
 
@@ -484,7 +484,7 @@ function startFetch(fetch, successcb, errorcb, progresscb, readystatechangecb) {
     {{{ runtimeKeepalivePop() }}}
     doCallback(() => {
       if (onerror) {{{ makeDynCall('vp', 'onerror') }}}(fetch);
-      else if (errorcb) errorcb(fetch);
+      else errorcb?.(fetch);
     });
   };
 
@@ -494,7 +494,7 @@ function startFetch(fetch, successcb, errorcb, progresscb, readystatechangecb) {
 #endif
     doCallback(() => {
       if (onreadystatechange) {{{ makeDynCall('vp', 'onreadystatechange') }}}(fetch);
-      else if (readystatechangecb) readystatechangecb(fetch);
+      else readystatechangecb?.(fetch);
     });
   };
 
@@ -517,7 +517,7 @@ function startFetch(fetch, successcb, errorcb, progresscb, readystatechangecb) {
       {{{ runtimeKeepalivePop() }}}
       doCallback(() => {
         if (onsuccess) {{{ makeDynCall('vp', 'onsuccess') }}}(fetch);
-        else if (successcb) successcb(fetch);
+        else successcb?.(fetch);
       });
     };
     var storeError = (fetch, xhr, e) => {
@@ -527,7 +527,7 @@ function startFetch(fetch, successcb, errorcb, progresscb, readystatechangecb) {
       {{{ runtimeKeepalivePop() }}}
       doCallback(() => {
         if (onsuccess) {{{ makeDynCall('vp', 'onsuccess') }}}(fetch);
-        else if (successcb) successcb(fetch);
+        else successcb?.(fetch);
       });
     };
     fetchCacheData(Fetch.dbInstance, fetch, xhr.response, storeSuccess, storeError);
diff --git a/src/cpuprofiler.js b/src/cpuprofiler.js
index 8929f6e07ded0..79d06b37c244c 100644
--- a/src/cpuprofiler.js
+++ b/src/cpuprofiler.js
@@ -148,37 +148,35 @@ var emscriptenCpuProfiler = {
   createSection: function createSection(number, name, drawColor, traceable) {
     while (this.sections.length <= number) this.sections.push(null); // Keep an array structure.
     var sect = this.sections[number];
-    if (!sect) {
-      sect = {
-        count: 0,
-        name,
-        startTick: 0,
-        accumulatedTimeInsideMainLoop: 0,
-        accumulatedTimeOutsideMainLoop: 0,
-        frametimesInsideMainLoop: [],
-        frametimesOutsideMainLoop: [],
-        drawColor,
-        traceable,
-        accumulatedFrameTimeInsideMainLoop: function(startX, numSamples) {
-          var total = 0;
-          numSamples = Math.min(numSamples, this.frametimesInsideMainLoop.length);
-          for (var i = 0; i < numSamples; ++i) {
-            var x = (startX + i) % this.frametimesInsideMainLoop.length;
-            if (this.frametimesInsideMainLoop[x]) total += this.frametimesInsideMainLoop[x];
-          }
-          return total;
-        },
-        accumulatedFrameTimeOutsideMainLoop: function(startX, numSamples) {
-          var total = 0;
-          numSamples = Math.min(numSamples, this.frametimesInsideMainLoop.length);
-          for (var i = 0; i < numSamples; ++i) {
-            var x = (startX + i) % this.frametimesInsideMainLoop.length;
-            if (this.frametimesOutsideMainLoop[x]) total += this.frametimesOutsideMainLoop[x];
-          }
-          return total;
+    sect ||= {
+      count: 0,
+      name,
+      startTick: 0,
+      accumulatedTimeInsideMainLoop: 0,
+      accumulatedTimeOutsideMainLoop: 0,
+      frametimesInsideMainLoop: [],
+      frametimesOutsideMainLoop: [],
+      drawColor,
+      traceable,
+      accumulatedFrameTimeInsideMainLoop: function(startX, numSamples) {
+        var total = 0;
+        numSamples = Math.min(numSamples, this.frametimesInsideMainLoop.length);
+        for (var i = 0; i < numSamples; ++i) {
+          var x = (startX + i) % this.frametimesInsideMainLoop.length;
+          if (this.frametimesInsideMainLoop[x]) total += this.frametimesInsideMainLoop[x];
         }
-      };
-    }
+        return total;
+      },
+      accumulatedFrameTimeOutsideMainLoop: function(startX, numSamples) {
+        var total = 0;
+        numSamples = Math.min(numSamples, this.frametimesInsideMainLoop.length);
+        for (var i = 0; i < numSamples; ++i) {
+          var x = (startX + i) % this.frametimesInsideMainLoop.length;
+          if (this.frametimesOutsideMainLoop[x]) total += this.frametimesOutsideMainLoop[x];
+        }
+        return total;
+      }
+    };
     sect.name = name;
     this.sections[number] = sect;
   },
@@ -532,14 +530,14 @@ var emscriptenCpuProfiler = {
   },
 
   detectWebGLContext: function() {
-    if (Module['canvas'] && Module['canvas'].GLctxObject && Module['canvas'].GLctxObject.GLctx) return Module['canvas'].GLctxObject.GLctx;
+    if (Module['canvas']?.GLctxObject?.GLctx) return Module['canvas'].GLctxObject.GLctx;
     else if (typeof GLctx != 'undefined') return GLctx;
     else if (Module.ctx) return Module.ctx;
     return null;
   },
 
   toggleHookWebGL: function(glCtx) {
-    if (!glCtx) glCtx = this.detectWebGLContext();
+    glCtx ||= this.detectWebGLContext();
     if (this.hookedWebGLContexts.includes(glCtx)) this.unhookWebGL(glCtx);
     else this.hookWebGL(glCtx);
   },
@@ -563,7 +561,7 @@ var emscriptenCpuProfiler = {
   },
 
   unhookWebGL: function(glCtx) {
-    if (!glCtx) glCtx = this.detectWebGLContext();
+    glCtx ||= this.detectWebGLContext();
     if (!glCtx.cpuprofilerAlreadyHooked) return;
     glCtx.cpuprofilerAlreadyHooked = false;
     this.hookedWebGLContexts.splice(this.hookedWebGLContexts.indexOf(glCtx), 1);
@@ -601,7 +599,7 @@ var emscriptenCpuProfiler = {
   },
 
   hookWebGL: function(glCtx) {
-    if (!glCtx) glCtx = this.detectWebGLContext();
+    glCtx ||= this.detectWebGLContext();
     if (!glCtx) return;
     if (!((typeof WebGLRenderingContext != 'undefined' && glCtx instanceof WebGLRenderingContext)
      || (typeof WebGL2RenderingContext != 'undefined' && glCtx instanceof WebGL2RenderingContext))) {
diff --git a/src/embind/embind.js b/src/embind/embind.js
index e1d999a3f15d8..629b853d7611e 100644
--- a/src/embind/embind.js
+++ b/src/embind/embind.js
@@ -1370,9 +1370,7 @@ var LibraryEmbind = {
         return ptr;
       },
       destructor(ptr) {
-        if (this.rawDestructor) {
-          this.rawDestructor(ptr);
-        }
+        this.rawDestructor?.(ptr);
       },
       'argPackAdvance': GenericWireTypeSize,
       'readValueFromPointer': readPointer,
@@ -1806,12 +1804,8 @@ var LibraryEmbind = {
                            rawDestructor) => {
     name = readLatin1String(name);
     getActualType = embind__requireFunction(getActualTypeSignature, getActualType);
-    if (upcast) {
-      upcast = embind__requireFunction(upcastSignature, upcast);
-    }
-    if (downcast) {
-      downcast = embind__requireFunction(downcastSignature, downcast);
-    }
+    upcast &&= embind__requireFunction(upcastSignature, upcast);
+    downcast &&= embind__requireFunction(downcastSignature, downcast);
     rawDestructor = embind__requireFunction(destructorSignature, rawDestructor);
     var legalFunctionName = makeLegalFunctionName(name);
 
@@ -1866,9 +1860,7 @@ var LibraryEmbind = {
 
         if (registeredClass.baseClass) {
           // Keep track of class hierarchy. Used to allow sub-classes to inherit class functions.
-          if (registeredClass.baseClass.__derivedClasses === undefined) {
-            registeredClass.baseClass.__derivedClasses = [];
-          }
+          registeredClass.baseClass.__derivedClasses ??= [];
 
           registeredClass.baseClass.__derivedClasses.push(registeredClass);
         }
diff --git a/src/embind/emval.js b/src/embind/emval.js
index 7dc47fb2e5c9a..cea116ca4ded3 100644
--- a/src/embind/emval.js
+++ b/src/embind/emval.js
@@ -336,9 +336,7 @@ var LibraryEmVal = {
       }
       var rv = kind === /* CONSTRUCTOR */ 1 ? reflectConstruct(func, argN) : func.apply(obj, argN);
       for (var i = 0; i < argCount; ++i) {
-        if (types[i].deleteObject) {
-          types[i].deleteObject(argN[i]);
-        }
+        types[i].deleteObject?.(argN[i]);
       }
       return emval_returnValue(retType, destructorsRef, rv);
     };
diff --git a/src/gl-matrix.js b/src/gl-matrix.js
index 6dd0f80c787bc..99e8c069bcb30 100644
--- a/src/gl-matrix.js
+++ b/src/gl-matrix.js
@@ -180,7 +180,7 @@ vec3.multiply = function (vec, vec2, dest) {
  * _returns {vec3} dest if specified, vec otherwise
  */
 vec3.negate = function (vec, dest) {
-    if (!dest) { dest = vec; }
+    dest ||= vec;
 
     dest[0] = -vec[0];
     dest[1] = -vec[1];
@@ -221,7 +221,7 @@ vec3.scale = function (vec, val, dest) {
  * _returns {vec3} dest if specified, vec otherwise
  */
 vec3.normalize = function (vec, dest) {
-    if (!dest) { dest = vec; }
+    dest ||= vec;
 
     var x = vec[0], y = vec[1], z = vec[2],
         len = Math.sqrt(x * x + y * y + z * z);
@@ -255,7 +255,7 @@ vec3.normalize = function (vec, dest) {
  * _returns {vec3} dest if specified, vec otherwise
  */
 vec3.cross = function (vec, vec2, dest) {
-    if (!dest) { dest = vec; }
+    dest ||= vec;
 
     var x = vec[0], y = vec[1], z = vec[2],
         x2 = vec2[0], y2 = vec2[1], z2 = vec2[2];
@@ -300,7 +300,7 @@ vec3.dot = function (vec, vec2) {
  * _returns {vec3} dest if specified, vec otherwise
  */
 vec3.direction = function (vec, vec2, dest) {
-    if (!dest) { dest = vec; }
+    dest ||= vec;
 
     var x = vec[0] - vec2[0],
         y = vec[1] - vec2[1],
@@ -332,7 +332,7 @@ vec3.direction = function (vec, vec2, dest) {
  * _returns {vec3} dest if specified, vec otherwise
  */
 vec3.lerp = function (vec, vec2, lerp, dest) {
-    if (!dest) { dest = vec; }
+    dest ||= vec;
 
     dest[0] = vec[0] + lerp * (vec2[0] - vec[0]);
     dest[1] = vec[1] + lerp * (vec2[1] - vec[1]);
@@ -371,7 +371,7 @@ vec3.dist = function (vec, vec2) {
  * _returns {vec3} dest if specified, vec otherwise
  */
 vec3.unproject = function (vec, view, proj, viewport, dest) {
-    if (!dest) { dest = vec; }
+    dest ||= vec;
 
     var m = mat4.create();
     var v = new MatrixArray(4);
@@ -466,7 +466,7 @@ mat3.set = function (mat, dest) {
  * _returns dest if specified, otherwise a new mat3
  */
 mat3.identity = function (dest) {
-    if (!dest) { dest = mat3.create(); }
+    dest ||= mat3.create();
     dest[0] = 1;
     dest[1] = 0;
     dest[2] = 0;
@@ -522,7 +522,7 @@ mat3.transpose = function (mat, dest) {
  * _returns {mat4} dest if specified, a new mat4 otherwise
  */
 mat3.toMat4 = function (mat, dest) {
-    if (!dest) { dest = mat4.create(); }
+    dest ||= mat4.create();
 
     dest[15] = 1;
     dest[14] = 0;
@@ -635,7 +635,7 @@ mat4.set = function (mat, dest) {
  * _returns {mat4} dest
  */
 mat4.identity = function (dest) {
-    if (!dest) { dest = mat4.create(); }
+    dest ||= mat4.create();
     dest[0] = 1;
     dest[1] = 0;
     dest[2] = 0;
@@ -733,7 +733,7 @@ mat4.determinant = function (mat) {
  * @param {Object=} dest
  */
 mat4.inverse = function (mat, dest) {
-    if (!dest) { dest = mat; }
+    dest ||= mat;
 
     // Cache the matrix values (makes for huge speed increases!)
     var a00 = mat[0], a01 = mat[1], a02 = mat[2], a03 = mat[3],
@@ -790,7 +790,7 @@ mat4.inverse = function (mat, dest) {
  * _returns {mat4} dest is specified, a new mat4 otherwise
  */
 mat4.toRotationMat = function (mat, dest) {
-    if (!dest) { dest = mat4.create(); }
+    dest ||= mat4.create();
 
     dest[0] = mat[0];
     dest[1] = mat[1];
@@ -821,7 +821,7 @@ mat4.toRotationMat = function (mat, dest) {
  * _returns {mat3} dest is specified, a new mat3 otherwise
  */
 mat4.toMat3 = function (mat, dest) {
-    if (!dest) { dest = mat3.create(); }
+    dest ||= mat3.create();
 
     dest[0] = mat[0];
     dest[1] = mat[1];
@@ -862,7 +862,7 @@ mat4.toInverseMat3 = function (mat, dest) {
     if (!d) { return null; }
     id = 1 / d;
 
-    if (!dest) { dest = mat3.create(); }
+    dest ||= mat3.create();
 
     dest[0] = b01 * id;
     dest[1] = (-a22 * a01 + a02 * a21) * id;
@@ -885,7 +885,7 @@ mat4.toInverseMat3 = function (mat, dest) {
  * _param {mat4} [dest] mat4 receiving operation result. If not specified result is written to mat
  */
 mat4.multiply = function (mat, mat2, dest) {
-    if (!dest) { dest = mat; }
+    dest ||= mat;
 
     // Cache the matrix values (makes for huge speed increases!)
     var a00 = mat[0], a01 = mat[1], a02 = mat[2], a03 = mat[3],
@@ -929,7 +929,7 @@ mat4.multiply = function (mat, mat2, dest) {
  * _returns {vec3} dest if specified, vec otherwise
  */
 mat4.multiplyVec3 = function (mat, vec, dest) {
-    if (!dest) { dest = vec; }
+    dest ||= vec;
 
     var x = vec[0], y = vec[1], z = vec[2];
 
@@ -952,7 +952,7 @@ mat4.multiplyVec3 = function (mat, vec, dest) {
  * @param {Object=} dest
  */
 mat4.multiplyVec4 = function (mat, vec, dest) {
-    if (!dest) { dest = vec; }
+    dest ||= vec;
 
     var x = vec[0], y = vec[1], z = vec[2], w = vec[3];
 
@@ -1266,7 +1266,7 @@ mat4.rotateZ = function (mat, angle, dest) {
  * _returns {mat4} dest if specified, a new mat4 otherwise
  */
 mat4.frustum = function (left, right, bottom, top, near, far, dest) {
-    if (!dest) { dest = mat4.create(); }
+    dest ||= mat4.create();
     var rl = (right - left),
         tb = (top - bottom),
         fn = (far - near);
@@ -1320,7 +1320,7 @@ mat4.perspective = function (fovy, aspect, near, far, dest) {
  * _returns {mat4} dest if specified, a new mat4 otherwise
  */
 mat4.ortho = function (left, right, bottom, top, near, far, dest) {
-    if (!dest) { dest = mat4.create(); }
+    dest ||= mat4.create();
     var rl = (right - left),
         tb = (top - bottom),
         fn = (far - near);
@@ -1354,7 +1354,7 @@ mat4.ortho = function (left, right, bottom, top, near, far, dest) {
  * _returns {mat4} dest if specified, a new mat4 otherwise
  */
 mat4.lookAt = function (eye, center, up, dest) {
-    if (!dest) { dest = mat4.create(); }
+    dest ||= mat4.create();
 
     var x0, x1, x2, y0, y1, y2, z0, z1, z2, len,
         eyex = eye[0],
@@ -1452,7 +1452,7 @@ mat4.lookAt = function (eye, center, up, dest) {
  * _returns {mat4} dest if specified, a new mat4 otherwise
  */
 mat4.fromRotationTranslation = function (quat, vec, dest) {
-    if (!dest) { dest = mat4.create(); }
+    dest ||= mat4.create();
 
     // Quaternion math
     var x = quat[0], y = quat[1], z = quat[2], w = quat[3],
@@ -1658,7 +1658,7 @@ quat4.length = function (quat) {
  * _returns {quat4} dest if specified, quat otherwise
  */
 quat4.normalize = function (quat, dest) {
-    if (!dest) { dest = quat; }
+    dest ||= quat;
 
     var x = quat[0], y = quat[1], z = quat[2], w = quat[3],
         len = Math.sqrt(x * x + y * y + z * z + w * w);
@@ -1712,7 +1712,7 @@ quat4.add = function (quat, quat2, dest) {
  * _returns {quat4} dest if specified, quat otherwise
  */
 quat4.multiply = function (quat, quat2, dest) {
-    if (!dest) { dest = quat; }
+    dest ||= quat;
 
     var qax = quat[0], qay = quat[1], qaz = quat[2], qaw = quat[3],
         qbx = quat2[0], qby = quat2[1], qbz = quat2[2], qbw = quat2[3];
@@ -1735,7 +1735,7 @@ quat4.multiply = function (quat, quat2, dest) {
  * _returns dest if specified, vec otherwise
  */
 quat4.multiplyVec3 = function (quat, vec, dest) {
-    if (!dest) { dest = vec; }
+    dest ||= vec;
 
     var x = vec[0], y = vec[1], z = vec[2],
         qx = quat[0], qy = quat[1], qz = quat[2], qw = quat[3],
@@ -1787,7 +1787,7 @@ quat4.scale = function (quat, val, dest) {
  * _returns {mat3} dest if specified, a new mat3 otherwise
  */
 quat4.toMat3 = function (quat, dest) {
-    if (!dest) { dest = mat3.create(); }
+    dest ||= mat3.create();
 
     var x = quat[0], y = quat[1], z = quat[2], w = quat[3],
         x2 = x + x,
@@ -1828,7 +1828,7 @@ quat4.toMat3 = function (quat, dest) {
  * _returns {mat4} dest if specified, a new mat4 otherwise
  */
 quat4.toMat4 = function (quat, dest) {
-    if (!dest) { dest = mat4.create(); }
+    dest ||= mat4.create();
 
     var x = quat[0], y = quat[1], z = quat[2], w = quat[3],
         x2 = x + x,
@@ -1879,7 +1879,7 @@ quat4.toMat4 = function (quat, dest) {
  * _returns {quat4} dest if specified, quat otherwise
  */
 quat4.slerp = function (quat, quat2, slerp, dest) {
-    if (!dest) { dest = quat; }
+    dest ||= quat;
 
     var cosHalfTheta = quat[0] * quat2[0] + quat[1] * quat2[1] + quat[2] * quat2[2] + quat[3] * quat2[3],
         halfTheta,
diff --git a/src/headless.js b/src/headless.js
index 72baac8aa8284..18f8fa339addc 100644
--- a/src/headless.js
+++ b/src/headless.js
@@ -83,9 +83,7 @@ var window = {
   eventListeners: {},
   addEventListener(id, func) {
     var listeners = this.eventListeners[id];
-    if (!listeners) {
-      listeners = this.eventListeners[id] = [];
-    }
+    listeners ||= this.eventListeners[id] = [];
     listeners.push(func);
   },
   removeEventListener(id, func) {
@@ -161,17 +159,15 @@ var document = {
   },
   elements: {},
   querySelector(id) {
-    if (!document.elements[id]) {
-      document.elements[id] = {
-        classList: {
-          add() {},
-          remove() {},
-        },
-        eventListeners: {},
-        addEventListener: document.addEventListener,
-        removeEventListener: document.removeEventListener,
-        callEventListeners: document.callEventListeners,
-      };
+    document.elements[id] ||= {
+      classList: {
+        add() {},
+        remove() {},
+      },
+      eventListeners: {},
+      addEventListener: document.addEventListener,
+      removeEventListener: document.removeEventListener,
+      callEventListeners: document.callEventListeners,
     };
     return document.elements[id];
   },
@@ -214,7 +210,7 @@ var XMLHttpRequest = function() {
       } else {
         window.setTimeout(() => {
           this.doSend();
-          if (this.onload) this.onload();
+          this.onload?.();
         }, 0);
       }
     },
@@ -239,7 +235,7 @@ var Image = () => {
     this.complete = true;
     this.width = 64;
     this.height = 64;
-    if (this.onload) this.onload();
+    this.onload?.();
   });
 };
 var Worker = (workerPath) => {
@@ -252,7 +248,7 @@ var Worker = (workerPath) => {
 
   function duplicateJSON(json) {
     function handleTypedArrays(key, value) {
-      if (value && value.toString && value.toString().substring(0, 8) == '[object ' && value.length && value.byteLength) {
+      if (value?.toString && value.toString().substring(0, 8) == '[object ' && value.length && value.byteLength) {
         return Array.prototype.slice.call(value);
       }
       return value;
@@ -293,6 +289,4 @@ if (typeof console == 'undefined') {
 }
 
 // additional setup
-if (!Module['canvas']) {
-  Module['canvas'] = document.getElementById('canvas');
-}
+Module['canvas'] ||= document.getElementById('canvas');
diff --git a/src/library.js b/src/library.js
index e9fbd9b8180a8..c5d607c042af5 100644
--- a/src/library.js
+++ b/src/library.js
@@ -2394,7 +2394,7 @@ addToLibrary({
   _emscripten_get_now_is_monotonic: () => nowIsMonotonic,
 
   $warnOnce: (text) => {
-    if (!warnOnce.shown) warnOnce.shown = {};
+    warnOnce.shown ||= {};
     if (!warnOnce.shown[text]) {
       warnOnce.shown[text] = 1;
 #if ENVIRONMENT_MAY_BE_NODE
@@ -2474,7 +2474,7 @@ addToLibrary({
 
       if (flags & {{{ cDefs.EM_LOG_C_STACK }}}) {
         var orig = emscripten_source_map.originalPositionFor({line: lineno, column: column});
-        haveSourceMap = (orig && orig.source);
+        haveSourceMap = orig?.source;
         if (haveSourceMap) {
           if (flags & {{{ cDefs.EM_LOG_NO_PATHS }}}) {
             orig.source = orig.source.substring(orig.source.replace(/\\/g, "/").lastIndexOf('/')+1);
diff --git a/src/library_browser.js b/src/library_browser.js
index aaf20d7c5dd74..1f92242521ff4 100644
--- a/src/library_browser.js
+++ b/src/library_browser.js
@@ -95,7 +95,7 @@ var LibraryBrowser = {
           }
         }
         callUserCallback(func);
-        if (Module['postMainLoop']) Module['postMainLoop']();
+        Module['postMainLoop']?.();
       }
     },
     isFullscreen: false,
@@ -140,11 +140,11 @@ var LibraryBrowser = {
           ctx.drawImage(img, 0, 0);
           preloadedImages[name] = canvas;
           URL.revokeObjectURL(url);
-          if (onload) onload(byteArray);
+          onload?.(byteArray);
         };
         img.onerror = (event) => {
           err(`Image ${url} could not be decoded`);
-          if (onerror) onerror();
+          onerror?.();
         };
         img.src = url;
       };
@@ -160,13 +160,13 @@ var LibraryBrowser = {
           if (done) return;
           done = true;
           preloadedAudios[name] = audio;
-          if (onload) onload(byteArray);
+          onload?.(byteArray);
         }
         function fail() {
           if (done) return;
           done = true;
           preloadedAudios[name] = new Audio(); // empty shim
-          if (onerror) onerror();
+          onerror?.();
         }
         var b = new Blob([byteArray], { type: Browser.getMimetype(name) });
         var url = URL.createObjectURL(b); // XXX we never revoke this!
@@ -344,8 +344,8 @@ var LibraryBrowser = {
             Browser.updateCanvasDimensions(canvas);
           }
         }
-        if (Module['onFullScreen']) Module['onFullScreen'](Browser.isFullscreen);
-        if (Module['onFullscreen']) Module['onFullscreen'](Browser.isFullscreen);
+        Module['onFullScreen']?.(Browser.isFullscreen);
+        Module['onFullscreen']?.(Browser.isFullscreen);
       }
 
       if (!Browser.fullscreenHandlersInstalled) {
@@ -459,10 +459,8 @@ var LibraryBrowser = {
     },
 
     getUserMedia(func) {
-      if (!window.getUserMedia) {
-        window.getUserMedia = navigator['getUserMedia'] ||
+      window.getUserMedia ||= navigator['getUserMedia'] ||
                               navigator['mozGetUserMedia'];
-      }
       window.getUserMedia(func);
     },
 
@@ -593,7 +591,7 @@ var LibraryBrowser = {
             Browser.touches[touch.identifier] = coords;
           } else if (event.type === 'touchend' || event.type === 'touchmove') {
             var last = Browser.touches[touch.identifier];
-            if (!last) last = coords;
+            last ||= coords;
             Browser.lastTouches[touch.identifier] = last;
             Browser.touches[touch.identifier] = coords;
           }
@@ -733,7 +731,7 @@ var LibraryBrowser = {
     {{{ runtimeKeepalivePush() }}}
 
     var _suffix = UTF8ToString(suffix);
-    if (!Browser.asyncPrepareDataCounter) Browser.asyncPrepareDataCounter = 0;
+    Browser.asyncPrepareDataCounter ||= 0;
     var name = 'prepare_data_' + (Browser.asyncPrepareDataCounter++) + '.' + _suffix;
     var cname = stringToNewUTF8(name);
     FS.createPreloadedFile(
@@ -790,7 +788,7 @@ var LibraryBrowser = {
 
     var loadError = () => {
       {{{ runtimeKeepalivePop() }}}
-      if (onerror) onerror();
+      onerror?.();
     };
 
 #if ENVIRONMENT_MAY_BE_NODE && DYNAMIC_EXECUTION
diff --git a/src/library_ccall.js b/src/library_ccall.js
index 05d96fb73bea4..0c73ff7ecaaaa 100644
--- a/src/library_ccall.js
+++ b/src/library_ccall.js
@@ -86,7 +86,7 @@ addToLibrary({
       return convertReturnValue(ret);
     }
 #if ASYNCIFY
-  var asyncMode = opts && opts.async;
+  var asyncMode = opts?.async;
 #endif
 
 #if ASYNCIFY == 1
diff --git a/src/library_dylink.js b/src/library_dylink.js
index 6ff94267606f6..d58a5ce866d3b 100644
--- a/src/library_dylink.js
+++ b/src/library_dylink.js
@@ -218,9 +218,7 @@ var LibraryDylink = {
       }
 #endif
 
-      if (!GOT[symName]) {
-        GOT[symName] = new WebAssembly.Global({'value': '{{{ POINTER_WASM_TYPE }}}', 'mutable': true});
-      }
+      GOT[symName] ||= new WebAssembly.Global({'value': '{{{ POINTER_WASM_TYPE }}}', 'mutable': true});
       if (replace || GOT[symName].value == 0) {
 #if DYLINK_DEBUG == 2
         dbg(`updateGOT: before: ${symName} : ${GOT[symName].value}`);
@@ -713,7 +711,7 @@ var LibraryDylink = {
           if (!(prop in stubs)) {
             var resolved;
             stubs[prop] = function() {
-              if (!resolved) resolved = resolveSymbol(prop);
+              resolved ||= resolveSymbol(prop);
               return resolved.apply(null, arguments);
             };
           }
@@ -898,9 +896,7 @@ var LibraryDylink = {
       dbg(`setDylinkStackLimits for '${name}'`);
 #endif
       var lib = LDSO.loadedLibsByName[name];
-      if (lib.exports['__set_stack_limits']) {
-        lib.exports['__set_stack_limits']({{{ to64("stackTop") }}}, {{{ to64("stackMax") }}});
-      }
+      lib.exports['__set_stack_limits']?.({{{ to64("stackTop") }}}, {{{ to64("stackMax") }}});
     }
   },
 #endif
diff --git a/src/library_eventloop.js b/src/library_eventloop.js
index b6a71bd07d7ff..8bbc0883074cf 100644
--- a/src/library_eventloop.js
+++ b/src/library_eventloop.js
@@ -24,7 +24,7 @@ LibraryJSEventLoop = {
   // Just like setImmediate but returns an i32 that can be passed back
   // to wasm rather than a JS object.
   $setImmediateWrapped: (func) => {
-    if (!setImmediateWrapped.mapping) setImmediateWrapped.mapping = [];
+    setImmediateWrapped.mapping ||= [];
     var id = setImmediateWrapped.mapping.length;
     setImmediateWrapped.mapping[id] = setImmediate(() => {
       setImmediateWrapped.mapping[id] = undefined;
diff --git a/src/library_exceptions.js b/src/library_exceptions.js
index d97e704149efd..bfe919e890fe5 100644
--- a/src/library_exceptions.js
+++ b/src/library_exceptions.js
@@ -228,7 +228,7 @@ var LibraryExceptions = {
   $findMatchingCatch: (args) => {
     var thrown =
 #if EXCEPTION_STACK_TRACES
-      exceptionLast && exceptionLast.excPtr;
+      exceptionLast?.excPtr;
 #else
       exceptionLast;
 #endif
diff --git a/src/library_exports.js b/src/library_exports.js
index 3bf963c490a00..385d3c684e4fb 100644
--- a/src/library_exports.js
+++ b/src/library_exports.js
@@ -16,7 +16,7 @@ addToLibrary({
       // Record the created function pointer to each function object,
       // so that if the same function pointer is obtained several times,
       // the same address will be returned.
-      if (!exportedFunc.ptr) exportedFunc.ptr = addFunction(exportedFunc);
+      exportedFunc.ptr ||= addFunction(exportedFunc);
       return exportedFunc.ptr;
     }
 #if ASSERTIONS
diff --git a/src/library_fs.js b/src/library_fs.js
index b8df41f3683e2..aa917a19ce7fd 100644
--- a/src/library_fs.js
+++ b/src/library_fs.js
@@ -459,9 +459,7 @@ FS.staticInit();` +
         // override node's stream ops with the device's
         stream.stream_ops = device.stream_ops;
         // forward the open call
-        if (stream.stream_ops.open) {
-          stream.stream_ops.open(stream);
-        }
+        stream.stream_ops.open?.(stream);
       },
       llseek() {
         throw new FS.ErrnoError({{{ cDefs.ESPIPE }}});
diff --git a/src/library_fs_shared.js b/src/library_fs_shared.js
index 0e9426cc9f46f..cdc9d9ef5df11 100644
--- a/src/library_fs_shared.js
+++ b/src/library_fs_shared.js
@@ -57,16 +57,16 @@ addToLibrary({
     var dep = getUniqueRunDependency(`cp ${fullname}`); // might have several active requests for the same fullname
     function processData(byteArray) {
       function finish(byteArray) {
-        if (preFinish) preFinish();
+        preFinish?.();
         if (!dontCreateFile) {
           FS_createDataFile(parent, name, byteArray, canRead, canWrite, canOwn);
         }
-        if (onload) onload();
+        onload?.();
         removeRunDependency(dep);
       }
 #if !MINIMAL_RUNTIME
       if (FS_handledByPreloadPlugin(byteArray, fullname, finish, () => {
-        if (onerror) onerror();
+        onerror?.();
         removeRunDependency(dep);
       })) {
         return;
diff --git a/src/library_glemu.js b/src/library_glemu.js
index 190f01b262490..79fea2fd87f88 100644
--- a/src/library_glemu.js
+++ b/src/library_glemu.js
@@ -559,7 +559,7 @@ var LibraryGLEmulation = {
       GL.programShaders = {};
       var glAttachShader = _glAttachShader;
       _glAttachShader = _emscripten_glAttachShader = (program, shader) => {
-        if (!GL.programShaders[program]) GL.programShaders[program] = [];
+        GL.programShaders[program] ||= [];
         GL.programShaders[program].push(shader);
         glAttachShader(program, shader);
       };
@@ -1998,16 +1998,14 @@ var LibraryGLEmulation = {
       var attrib = GLImmediate.clientAttributes[name];
       if (!attrib) {
         for (var i = 0; i <= name; i++) { // keep flat
-          if (!GLImmediate.clientAttributes[i]) {
-            GLImmediate.clientAttributes[i] = {
-              name,
-              size,
-              type,
-              stride,
-              pointer,
-              offset: 0
-            };
-          }
+          GLImmediate.clientAttributes[i] ||= {
+            name,
+            size,
+            type,
+            stride,
+            pointer,
+            offset: 0
+          };
         }
       } else {
         attrib.name = name;
@@ -2925,7 +2923,7 @@ var LibraryGLEmulation = {
 #if GL_ASSERTIONS
         warnOnce('Rendering from planar client-side vertex arrays. This is a very slow emulation path! Use interleaved vertex arrays for best performance.');
 #endif
-        if (!GLImmediate.restrideBuffer) GLImmediate.restrideBuffer = _malloc(GL.MAX_TEMP_BUFFER_SIZE);
+        GLImmediate.restrideBuffer ||= _malloc(GL.MAX_TEMP_BUFFER_SIZE);
         var start = GLImmediate.restrideBuffer;
         bytes = 0;
         // calculate restrided offsets and total size
diff --git a/src/library_glew.js b/src/library_glew.js
index bac564de9e8d8..14e907ee72b9e 100644
--- a/src/library_glew.js
+++ b/src/library_glew.js
@@ -99,9 +99,7 @@ var LibraryGLEW = {
     },
 
     extensionIsSupported(name) {
-      if (!GLEW.extensions) {
-        GLEW.extensions = UTF8ToString(_glGetString(0x1F03)).split(' ');
-      }
+      GLEW.extensions ||= UTF8ToString(_glGetString(0x1F03)).split(' ');
 
       if (GLEW.extensions.includes(name))
         return 1;
diff --git a/src/library_glfw.js b/src/library_glfw.js
index 6201cf8955a6c..6bb35a497bb96 100644
--- a/src/library_glfw.js
+++ b/src/library_glfw.js
@@ -653,7 +653,7 @@ var LibraryGLFW = {
     refreshJoysticks: () => {
       // Produce a new Gamepad API sample if we are ticking a new game frame, or if not using emscripten_set_main_loop() at all to drive animation.
       if (Browser.mainLoop.currentFrameNumber !== GLFW.lastGamepadStateFrame || !Browser.mainLoop.currentFrameNumber) {
-        GLFW.lastGamepadState = navigator.getGamepads ? navigator.getGamepads() : (navigator.webkitGetGamepads ? navigator.webkitGetGamepads : []);
+        GLFW.lastGamepadState = navigator.getGamepads ? navigator.getGamepads() : (navigator.webkitGetGamepads || []);
         GLFW.lastGamepadStateFrame = Browser.mainLoop.currentFrameNumber;
 
         for (var joy = 0; joy < GLFW.lastGamepadState.length; ++joy) {
@@ -1219,9 +1219,7 @@ var LibraryGLFW = {
 
   glfwExtensionSupported__deps: ['glGetString'],
   glfwExtensionSupported: (extension) => {
-    if (!GLFW.extensions) {
-      GLFW.extensions = UTF8ToString(_glGetString(0x1F03)).split(' ');
-    }
+    GLFW.extensions ||= UTF8ToString(_glGetString(0x1F03)).split(' ');
 
     if (GLFW.extensions.includes(extension)) return 1;
 
@@ -1239,9 +1237,7 @@ var LibraryGLFW = {
 
 #if USE_GLFW == 3
   glfwGetVersionString: () => {
-    if (!GLFW.versionString) {
-      GLFW.versionString = stringToNewUTF8("3.2.1 JS WebGL Emscripten");
-    }
+    GLFW.versionString ||= stringToNewUTF8("3.2.1 JS WebGL Emscripten");
     return GLFW.versionString;
   },
 
@@ -1295,9 +1291,7 @@ var LibraryGLFW = {
   },
 
   glfwGetMonitorName: (mon) => {
-    if (!GLFW.monitorString) {
-      GLFW.monitorString = stringToNewUTF8("HTML5 WebGL Canvas");
-    }
+    GLFW.monitorString ||= stringToNewUTF8("HTML5 WebGL Canvas");
     return GLFW.monitorString;
   },
 
diff --git a/src/library_html5.js b/src/library_html5.js
index 50f7a220f96e6..abbf7a458619b 100644
--- a/src/library_html5.js
+++ b/src/library_html5.js
@@ -234,7 +234,7 @@ var LibraryHTML5 = {
       if (!target) return '';
       if (target == window) return '#window';
       if (target == screen) return '#screen';
-      return (target && target.nodeName) ? target.nodeName : '';
+      return target?.nodeName || '';
     },
 
     fullscreenEnabled() {
@@ -1070,7 +1070,7 @@ var LibraryHTML5 = {
     // If transitioning to windowed mode, report info about the element that just was fullscreen.
     var reportedElement = isFullscreen ? fullscreenElement : JSEvents.previousFullscreenElement;
     var nodeName = JSEvents.getNodeNameForTarget(reportedElement);
-    var id = (reportedElement && reportedElement.id) ? reportedElement.id : '';
+    var id = reportedElement?.id || '';
     stringToUTF8(nodeName, eventStruct + {{{ C_STRUCTS.EmscriptenFullscreenChangeEvent.nodeName }}}, {{{ cDefs.EM_HTML5_LONG_STRING_LEN_BYTES }}});
     stringToUTF8(id, eventStruct + {{{ C_STRUCTS.EmscriptenFullscreenChangeEvent.id }}}, {{{ cDefs.EM_HTML5_LONG_STRING_LEN_BYTES }}});
     {{{ makeSetValue('eventStruct', C_STRUCTS.EmscriptenFullscreenChangeEvent.elementWidth, 'reportedElement ? reportedElement.clientWidth : 0', 'i32') }}};
@@ -1550,7 +1550,7 @@ var LibraryHTML5 = {
   emscripten_enter_soft_fullscreen__proxy: 'sync',
   emscripten_enter_soft_fullscreen: (target, fullscreenStrategy) => {
 #if !DISABLE_DEPRECATED_FIND_EVENT_TARGET_BEHAVIOR
-    if (!target) target = '#canvas';
+    target ||= '#canvas';
 #endif
     target = findEventTarget(target);
     if (!target) return {{{ cDefs.EMSCRIPTEN_RESULT_UNKNOWN_TARGET }}};
@@ -1608,7 +1608,7 @@ var LibraryHTML5 = {
   emscripten_exit_soft_fullscreen__deps: ['$restoreOldWindowedStyle'],
   emscripten_exit_soft_fullscreen__proxy: 'sync',
   emscripten_exit_soft_fullscreen: () => {
-    if (restoreOldWindowedStyle) restoreOldWindowedStyle();
+    restoreOldWindowedStyle?.();
     restoreOldWindowedStyle = null;
 
     return {{{ cDefs.EMSCRIPTEN_RESULT_SUCCESS }}};
@@ -1655,7 +1655,7 @@ var LibraryHTML5 = {
 #endif
     {{{ makeSetValue('eventStruct', C_STRUCTS.EmscriptenPointerlockChangeEvent.isActive, 'isPointerlocked', 'i32') }}};
     var nodeName = JSEvents.getNodeNameForTarget(pointerLockElement);
-    var id = (pointerLockElement && pointerLockElement.id) ? pointerLockElement.id : '';
+    var id = pointerLockElement?.id || '';
     stringToUTF8(nodeName, eventStruct + {{{ C_STRUCTS.EmscriptenPointerlockChangeEvent.nodeName }}}, {{{ cDefs.EM_HTML5_LONG_STRING_LEN_BYTES }}});
     stringToUTF8(id, eventStruct + {{{ C_STRUCTS.EmscriptenPointerlockChangeEvent.id }}}, {{{ cDefs.EM_HTML5_LONG_STRING_LEN_BYTES }}});
   },
@@ -2323,7 +2323,7 @@ var LibraryHTML5 = {
     if (!canvas.controlTransferredOffscreen) {
 #endif
       var autoResizeViewport = false;
-      if (canvas.GLctxObject && canvas.GLctxObject.GLctx) {
+      if (canvas.GLctxObject?.GLctx) {
         var prevViewport = canvas.GLctxObject.GLctx.getParameter(0xBA2 /* GL_VIEWPORT */);
         // TODO: Perhaps autoResizeViewport should only be true if FBO 0 is currently active?
         autoResizeViewport = (prevViewport[0] === 0 && prevViewport[1] === 0 && prevViewport[2] === canvas.width && prevViewport[3] === canvas.height);
diff --git a/src/library_memfs.js b/src/library_memfs.js
index 78bb247733348..7eac15d236ef8 100644
--- a/src/library_memfs.js
+++ b/src/library_memfs.js
@@ -16,55 +16,53 @@ addToLibrary({
         // no supported
         throw new FS.ErrnoError({{{ cDefs.EPERM }}});
       }
-      if (!MEMFS.ops_table) {
-        MEMFS.ops_table = {
-          dir: {
-            node: {
-              getattr: MEMFS.node_ops.getattr,
-              setattr: MEMFS.node_ops.setattr,
-              lookup: MEMFS.node_ops.lookup,
-              mknod: MEMFS.node_ops.mknod,
-              rename: MEMFS.node_ops.rename,
-              unlink: MEMFS.node_ops.unlink,
-              rmdir: MEMFS.node_ops.rmdir,
-              readdir: MEMFS.node_ops.readdir,
-              symlink: MEMFS.node_ops.symlink
-            },
-            stream: {
-              llseek: MEMFS.stream_ops.llseek
-            }
-          },
-          file: {
-            node: {
-              getattr: MEMFS.node_ops.getattr,
-              setattr: MEMFS.node_ops.setattr
-            },
-            stream: {
-              llseek: MEMFS.stream_ops.llseek,
-              read: MEMFS.stream_ops.read,
-              write: MEMFS.stream_ops.write,
-              allocate: MEMFS.stream_ops.allocate,
-              mmap: MEMFS.stream_ops.mmap,
-              msync: MEMFS.stream_ops.msync
-            }
+      MEMFS.ops_table ||= {
+        dir: {
+          node: {
+            getattr: MEMFS.node_ops.getattr,
+            setattr: MEMFS.node_ops.setattr,
+            lookup: MEMFS.node_ops.lookup,
+            mknod: MEMFS.node_ops.mknod,
+            rename: MEMFS.node_ops.rename,
+            unlink: MEMFS.node_ops.unlink,
+            rmdir: MEMFS.node_ops.rmdir,
+            readdir: MEMFS.node_ops.readdir,
+            symlink: MEMFS.node_ops.symlink
           },
-          link: {
-            node: {
-              getattr: MEMFS.node_ops.getattr,
-              setattr: MEMFS.node_ops.setattr,
-              readlink: MEMFS.node_ops.readlink
-            },
-            stream: {}
+          stream: {
+            llseek: MEMFS.stream_ops.llseek
+          }
+        },
+        file: {
+          node: {
+            getattr: MEMFS.node_ops.getattr,
+            setattr: MEMFS.node_ops.setattr
           },
-          chrdev: {
-            node: {
-              getattr: MEMFS.node_ops.getattr,
-              setattr: MEMFS.node_ops.setattr
-            },
-            stream: FS.chrdev_stream_ops
+          stream: {
+            llseek: MEMFS.stream_ops.llseek,
+            read: MEMFS.stream_ops.read,
+            write: MEMFS.stream_ops.write,
+            allocate: MEMFS.stream_ops.allocate,
+            mmap: MEMFS.stream_ops.mmap,
+            msync: MEMFS.stream_ops.msync
           }
-        };
-      }
+        },
+        link: {
+          node: {
+            getattr: MEMFS.node_ops.getattr,
+            setattr: MEMFS.node_ops.setattr,
+            readlink: MEMFS.node_ops.readlink
+          },
+          stream: {}
+        },
+        chrdev: {
+          node: {
+            getattr: MEMFS.node_ops.getattr,
+            setattr: MEMFS.node_ops.setattr
+          },
+          stream: FS.chrdev_stream_ops
+        }
+      };
       var node = FS.createNode(parent, name, mode, dev);
       if (FS.isDir(node.mode)) {
         node.node_ops = MEMFS.ops_table.dir.node;
diff --git a/src/library_pthread.js b/src/library_pthread.js
index b3d4d27199e4c..e39bdb989d71f 100644
--- a/src/library_pthread.js
+++ b/src/library_pthread.js
@@ -767,8 +767,8 @@ var LibraryPThread = {
     if (transferredCanvasNames == (-1 >>> 0)) transferredCanvasNames = '{{{ OFFSCREENCANVASES_TO_PTHREAD }}}';
     else
 #endif
-    if (transferredCanvasNames) transferredCanvasNames = UTF8ToString(transferredCanvasNames).trim();
-    if (transferredCanvasNames) transferredCanvasNames = transferredCanvasNames.split(',');
+    transferredCanvasNames &&= UTF8ToString(transferredCanvasNames).trim();
+    transferredCanvasNames &&= transferredCanvasNames.split(',');
 #if GL_DEBUG
     dbg(`pthread_create: transferredCanvasNames="${transferredCanvasNames}"`);
 #endif
diff --git a/src/library_sdl.js b/src/library_sdl.js
index 9fd29009630b9..c0ef45cff3b04 100644
--- a/src/library_sdl.js
+++ b/src/library_sdl.js
@@ -1726,7 +1726,7 @@ var LibrarySDL = {
     if (title) {
       _emscripten_set_window_title(title);
     }
-    icon = icon && UTF8ToString(icon);
+    icon &&= UTF8ToString(icon);
   },
 
   // TODO
@@ -1747,9 +1747,7 @@ var LibrarySDL = {
   SDL_GetKeyName__proxy: 'sync',
   SDL_GetKeyName__deps: ['$stringToNewUTF8'],
   SDL_GetKeyName: (key) => {
-    if (!SDL.keyName) {
-      SDL.keyName = stringToNewUTF8('unknown key');
-    }
+    SDL.keyName ||= stringToNewUTF8('unknown key');
     return SDL.keyName;
   },
 
@@ -1800,9 +1798,7 @@ var LibrarySDL = {
   SDL_GetError__proxy: 'sync',
   SDL_GetError__deps: ['$stringToNewUTF8'],
   SDL_GetError: () => {
-    if (!SDL.errorMessage) {
-      SDL.errorMessage = stringToNewUTF8("unknown SDL-emscripten error");
-    }
+    SDL.errorMessage ||= stringToNewUTF8("unknown SDL-emscripten error");
     return SDL.errorMessage;
   },
 
@@ -2982,7 +2978,7 @@ var LibrarySDL = {
       return count;
     }
     var info = SDL.channels[channel];
-    if (info && info.audio && !info.audio.paused) {
+    if (info?.audio && !info.audio.paused) {
       return 1;
     }
     return 0;
@@ -2998,7 +2994,7 @@ var LibrarySDL = {
     }
     /** @type {{ audio: HTMLMediaElement }} */
     var info = SDL.channels[channel];
-    if (info && info.audio) {
+    if (info?.audio) {
       info.audio.pause();
     } else {
       //err(`Mix_Pause: no sound found for channel: ${channel}`);
@@ -3016,14 +3012,14 @@ var LibrarySDL = {
       return pausedCount;
     }
     var info = SDL.channels[channel];
-    if (info && info.audio && info.audio.paused) {
+    if (info?.audio?.paused) {
       return 1;
     }
     return 0;
   },
 
   Mix_PausedMusic__proxy: 'sync',
-  Mix_PausedMusic: () => (SDL.music.audio && SDL.music.audio.paused) ? 1 : 0,
+  Mix_PausedMusic: () => SDL.music.audio?.paused ? 1 : 0,
 
   // http://www.libsdl.org/projects/SDL_mixer/docs/SDL_mixer_33.html#SEC33
   Mix_Resume__proxy: 'sync',
@@ -3035,7 +3031,7 @@ var LibrarySDL = {
       return;
     }
     var info = SDL.channels[channel];
-    if (info && info.audio) info.audio.play();
+    if (info?.audio) info.audio.play();
   },
 
   // SDL TTF
@@ -3294,7 +3290,7 @@ var LibrarySDL = {
 
   SDL_GL_SwapBuffers__proxy: 'sync',
   SDL_GL_SwapBuffers: () => {
-    if (Browser.doSwapBuffers) Browser.doSwapBuffers(); // in workers, this is used to send out a buffered frame
+    Browser.doSwapBuffers?.(); // in workers, this is used to send out a buffered frame
   },
 
   // SDL 2
diff --git a/src/library_strings.js b/src/library_strings.js
index 3e84803d258d5..d211460230d77 100644
--- a/src/library_strings.js
+++ b/src/library_strings.js
@@ -364,9 +364,7 @@ addToLibrary({
     assert(typeof maxBytesToWrite == 'number', 'stringToUTF16(str, outPtr, maxBytesToWrite) is missing the third parameter that specifies the length of the output buffer!');
 #endif
     // Backwards compatibility: if max bytes is not specified, assume unsafe unbounded write is allowed.
-    if (maxBytesToWrite === undefined) {
-      maxBytesToWrite = 0x7FFFFFFF;
-    }
+    maxBytesToWrite ??= 0x7FFFFFFF;
     if (maxBytesToWrite < 2) return 0;
     maxBytesToWrite -= 2; // Null terminator.
     var startPtr = outPtr;
@@ -439,9 +437,7 @@ addToLibrary({
     assert(typeof maxBytesToWrite == 'number', 'stringToUTF32(str, outPtr, maxBytesToWrite) is missing the third parameter that specifies the length of the output buffer!');
 #endif
     // Backwards compatibility: if max bytes is not specified, assume unsafe unbounded write is allowed.
-    if (maxBytesToWrite === undefined) {
-      maxBytesToWrite = 0x7FFFFFFF;
-    }
+    maxBytesToWrite ??= 0x7FFFFFFF;
     if (maxBytesToWrite < 4) return 0;
     var startPtr = outPtr;
     var endPtr = startPtr + maxBytesToWrite - 4;
diff --git a/src/library_syscall.js b/src/library_syscall.js
index d6744c804739d..2caa081a88efa 100644
--- a/src/library_syscall.js
+++ b/src/library_syscall.js
@@ -710,9 +710,7 @@ var SyscallsLibrary = {
   __syscall_getdents64__deps: ['$stringToUTF8'],
   __syscall_getdents64: (fd, dirp, count) => {
     var stream = SYSCALLS.getStreamFromFD(fd)
-    if (!stream.getdents) {
-      stream.getdents = FS.readdir(stream.path);
-    }
+    stream.getdents ||= FS.readdir(stream.path);
 
     var struct_size = {{{ C_STRUCTS.dirent.__size__ }}};
     var pos = 0;
diff --git a/src/library_wasi.js b/src/library_wasi.js
index 860439fced02d..9551f69dcc1d7 100644
--- a/src/library_wasi.js
+++ b/src/library_wasi.js
@@ -29,7 +29,7 @@ var WasiLibrary = {
       PThread.terminateAllThreads();
 #endif
 #if expectToReceiveOnModule('onExit')
-      if (Module['onExit']) Module['onExit'](code);
+      Module['onExit']?.(code);
 #endif
       ABORT = true;
     }
@@ -551,7 +551,7 @@ var WasiLibrary = {
       });
     });
 #else
-    if (stream.stream_ops && stream.stream_ops.fsync) {
+    if (stream.stream_ops?.fsync) {
       return stream.stream_ops.fsync(stream);
     }
     return 0; // we can't do anything synchronously; the in-memory FS is already synced to
diff --git a/src/library_wasmfs.js b/src/library_wasmfs.js
index 34fcaf703ef3d..e2ca6ed4d2f9e 100644
--- a/src/library_wasmfs.js
+++ b/src/library_wasmfs.js
@@ -514,7 +514,7 @@ FS.init();
   $FS_create__deps: ['$FS_mknod'],
   $FS_create: (path, mode) => {
     // Default settings copied from the legacy JS FS API.
-    mode = mode !== undefined ? mode : 438 /* 0666 */;
+    mode = mode ?? 438 /* 0666 */;
     mode &= {{{ cDefs.S_IALLUGO }}};
     mode |= {{{ cDefs.S_IFREG }}};
     return FS_mknod(path, mode, 0);
@@ -542,7 +542,7 @@ FS.init();
 
   $FS_mkdir__deps: ['_wasmfs_mkdir'],
   $FS_mkdir: (path, mode) => FS.handleError(withStackSave(() => {
-    mode = mode !== undefined ? mode : 511 /* 0777 */;
+    mode = mode ?? 511 /* 0777 */;
     var buffer = stringToUTF8OnStack(path);
     return __wasmfs_mkdir(buffer, mode);
   })),
diff --git a/src/library_webgl.js b/src/library_webgl.js
index 311fba64bd734..d3839045b0012 100644
--- a/src/library_webgl.js
+++ b/src/library_webgl.js
@@ -227,9 +227,7 @@ var LibraryGL = {
     // is remembered, and subsequent errors are discarded until the user has cleared the stored error by a call to glGetError().
     recordError: function recordError(errorCode) {
 #if GL_TRACK_ERRORS
-      if (!GL.lastError) {
-        GL.lastError = errorCode;
-      }
+      GL.lastError ||= errorCode;
 #endif
     },
     // Get a new ID for a texture/buffer/etc., while keeping the table dense and fast. Creation is fairly rare so it is worth optimizing lookups later.
@@ -1047,7 +1045,7 @@ var LibraryGL = {
 #endif
 
       GL.currentContext = GL.contexts[contextHandle]; // Active Emscripten GL layer context object.
-      Module.ctx = GLctx = GL.currentContext && GL.currentContext.GLctx; // Active WebGL context object.
+      Module.ctx = GLctx = GL.currentContext?.GLctx; // Active WebGL context object.
       return !(contextHandle && !GLctx);
     },
 
@@ -1071,7 +1069,7 @@ var LibraryGL = {
     // code here, so that GLES2 code can operate without changing behavior.
     initExtensions: (context) => {
       // If this function is called without a specific context object, init the extensions of the currently active context.
-      if (!context) context = GL.currentContext;
+      context ||= GL.currentContext;
 
       if (context.initExtensionsDone) return;
       context.initExtensionsDone = true;
diff --git a/src/library_websocket.js b/src/library_websocket.js
index 25349b65f1a4b..4ea12baaa66e1 100644
--- a/src/library_websocket.js
+++ b/src/library_websocket.js
@@ -137,7 +137,7 @@ var LibraryWebSocket = {
 //    if (thread == {{{ cDefs.EM_CALLBACK_THREAD_CONTEXT_CALLING_THREAD }}} ||
 //      (thread == _pthread_self()) return emscripten_websocket_set_onopen_callback_on_calling_thread(socketId, userData, callbackFunc);
 
-    if (!WS.socketEvent) WS.socketEvent = _malloc(1024); // TODO: sizeof(EmscriptenWebSocketCloseEvent), which is the largest event struct
+    WS.socketEvent ||= _malloc(1024); // TODO: sizeof(EmscriptenWebSocketCloseEvent), which is the largest event struct
 
     var socket = WS.sockets[socketId];
     if (!socket) {
@@ -163,7 +163,7 @@ var LibraryWebSocket = {
   emscripten_websocket_set_onerror_callback_on_thread__deps: ['$WS'],
   emscripten_websocket_set_onerror_callback_on_thread__proxy: 'sync',
   emscripten_websocket_set_onerror_callback_on_thread: (socketId, userData, callbackFunc, thread) => {
-    if (!WS.socketEvent) WS.socketEvent = _malloc(1024); // TODO: sizeof(EmscriptenWebSocketCloseEvent), which is the largest event struct
+    WS.socketEvent ||= _malloc(1024); // TODO: sizeof(EmscriptenWebSocketCloseEvent), which is the largest event struct
 
     var socket = WS.sockets[socketId];
     if (!socket) {
@@ -189,7 +189,7 @@ var LibraryWebSocket = {
   emscripten_websocket_set_onclose_callback_on_thread__deps: ['$WS', '$stringToUTF8'],
   emscripten_websocket_set_onclose_callback_on_thread__proxy: 'sync',
   emscripten_websocket_set_onclose_callback_on_thread: (socketId, userData, callbackFunc, thread) => {
-    if (!WS.socketEvent) WS.socketEvent = _malloc(1024); // TODO: sizeof(EmscriptenWebSocketCloseEvent), which is the largest event struct
+    WS.socketEvent ||= _malloc(1024); // TODO: sizeof(EmscriptenWebSocketCloseEvent), which is the largest event struct
 
     var socket = WS.sockets[socketId];
     if (!socket) {
@@ -218,7 +218,7 @@ var LibraryWebSocket = {
   emscripten_websocket_set_onmessage_callback_on_thread__deps: ['$WS', '$stringToNewUTF8', 'malloc', 'free'],
   emscripten_websocket_set_onmessage_callback_on_thread__proxy: 'sync',
   emscripten_websocket_set_onmessage_callback_on_thread: (socketId, userData, callbackFunc, thread) => {
-    if (!WS.socketEvent) WS.socketEvent = _malloc(1024); // TODO: sizeof(EmscriptenWebSocketCloseEvent), which is the largest event struct
+    WS.socketEvent ||= _malloc(1024); // TODO: sizeof(EmscriptenWebSocketCloseEvent), which is the largest event struct
 
     var socket = WS.sockets[socketId];
     if (!socket) {
diff --git a/src/library_workerfs.js b/src/library_workerfs.js
index 2db3e9aa4cdbd..6e5ab3cf853d9 100644
--- a/src/library_workerfs.js
+++ b/src/library_workerfs.js
@@ -28,9 +28,7 @@ addToLibrary({
           // are just their corresponding parts within their given path,
           // rather than incremental aggregates which include their parent's
           // directories.
-          if (!createdParents[curr]) {
-            createdParents[curr] = WORKERFS.createNode(parent, parts[i], WORKERFS.DIR_MODE, 0);
-          }
+          createdParents[curr] ||= WORKERFS.createNode(parent, parts[i], WORKERFS.DIR_MODE, 0);
           parent = createdParents[curr];
         }
         return parent;
diff --git a/src/memoryprofiler.js b/src/memoryprofiler.js
index 7008abae839bc..d42cbeaabbc08 100644
--- a/src/memoryprofiler.js
+++ b/src/memoryprofiler.js
@@ -190,7 +190,7 @@ var emscriptenMemoryProfiler = {
     if (!self.pagePreRunIsFinished) self.sizeOfPreRunAllocatedPtr[ptr] = size;
 
     var loc = new Error().stack.toString();
-    if (!self.allocationsAtLoc[loc]) self.allocationsAtLoc[loc] = [0, 0, self.filterCallstackForMalloc(loc)];
+    self.allocationsAtLoc[loc] ||= [0, 0, self.filterCallstackForMalloc(loc)];
     self.allocationsAtLoc[loc][0] += 1;
     self.allocationsAtLoc[loc][1] += size;
     self.allocationSitePtrs[ptr] = loc;
@@ -247,7 +247,7 @@ var emscriptenMemoryProfiler = {
     emscriptenMemoryProfiler.recordStackWatermark();
 
     // Add a tracking mechanism to detect when VFS loading is complete.
-    if (!Module['preRun']) Module['preRun'] = [];
+    Module['preRun'] ||= [];
     Module['preRun'].push(emscriptenMemoryProfiler.onPreloadComplete);
 
     if (emscriptenMemoryProfiler.hookStackAlloc && typeof stackAlloc == 'function') {
@@ -563,9 +563,7 @@ var emscriptenMemoryProfiler = {
           stack = self.filterCallstackAfterFunctionName(stack, s);
         }
         sbrk.filteredStack = stack;
-        if (!uniqueSources[stack]) {
-          uniqueSources[stack] = self.hsvToRgb(Object.keys(uniqueSources).length * 0.618033988749895 % 1, 0.5, 0.95);
-        }
+        uniqueSources[stack] ||= self.hsvToRgb(Object.keys(uniqueSources).length * 0.618033988749895 % 1, 0.5, 0.95);
         self.drawContext.fillStyle = sbrk.color = uniqueSources[stack];
         self.fillRect(sbrk.begin, sbrk.end, 0.25);
       }
diff --git a/src/parseTools.js b/src/parseTools.js
index 053d5d7d0b64c..2252a59fa95c3 100644
--- a/src/parseTools.js
+++ b/src/parseTools.js
@@ -766,7 +766,7 @@ function isSymbolNeeded(symName) {
 
 function makeRemovedModuleAPIAssert(moduleName, localName) {
   if (!ASSERTIONS) return '';
-  if (!localName) localName = moduleName;
+  localName ||= moduleName;
   return `legacyModuleProp('${moduleName}', '${localName}');`;
 }
 
@@ -778,7 +778,7 @@ function checkReceiving(name) {
 
 // Make code to receive a value on the incoming Module object.
 function makeModuleReceive(localName, moduleName) {
-  if (!moduleName) moduleName = localName;
+  moduleName ||= localName;
   checkReceiving(moduleName);
   let ret = '';
   if (expectToReceiveOnModule(moduleName)) {
@@ -800,7 +800,7 @@ function makeModuleReceiveExpr(name, defaultValue) {
 }
 
 function makeModuleReceiveWithVar(localName, moduleName, defaultValue, noAssert) {
-  if (!moduleName) moduleName = localName;
+  moduleName ||= localName;
   checkReceiving(moduleName);
   let ret = `var ${localName}`;
   if (!expectToReceiveOnModule(moduleName)) {
diff --git a/src/polyfill/bigint64array.js b/src/polyfill/bigint64array.js
index 5828b609bad9d..e237e19d2224c 100644
--- a/src/polyfill/bigint64array.js
+++ b/src/polyfill/bigint64array.js
@@ -39,9 +39,7 @@ if (typeof globalThis.BigInt64Array === "undefined") {
       var proxy = new Proxy(
         {
           slice(min, max) {
-            if (max === undefined) {
-              max = array.length;
-            }
+            max ??= array.length;
             var new_buf = array.slice(min * 2, max * 2);
             return createBigInt64Array(new_buf);
           },
@@ -64,9 +62,7 @@ if (typeof globalThis.BigInt64Array === "undefined") {
             return proxy;
           },
           set(source, targetOffset) {
-            if (targetOffset === undefined) {
-              targetOffset = 0;
-            }
+            targetOffset ??= 0;
             if (2 * (source.length + targetOffset) > array.length) {
               // This is the Chrome error message
               // Firefox: "invalid or out-of-range index"
diff --git a/src/preamble.js b/src/preamble.js
index a368db2c43615..4a3cc26c0f66d 100644
--- a/src/preamble.js
+++ b/src/preamble.js
@@ -361,9 +361,7 @@ function addRunDependency(id) {
   runDependencies++;
 
 #if expectToReceiveOnModule('monitorRunDependencies')
-  if (Module['monitorRunDependencies']) {
-    Module['monitorRunDependencies'](runDependencies);
-  }
+  Module['monitorRunDependencies']?.(runDependencies);
 #endif
 
 #if ASSERTIONS
@@ -401,9 +399,7 @@ function removeRunDependency(id) {
   runDependencies--;
 
 #if expectToReceiveOnModule('monitorRunDependencies')
-  if (Module['monitorRunDependencies']) {
-    Module['monitorRunDependencies'](runDependencies);
-  }
+  Module['monitorRunDependencies']?.(runDependencies);
 #endif
 
 #if ASSERTIONS
@@ -430,9 +426,7 @@ function removeRunDependency(id) {
 /** @param {string|number=} what */
 function abort(what) {
 #if expectToReceiveOnModule('onAbort')
-  if (Module['onAbort']) {
-    Module['onAbort'](what);
-  }
+  Module['onAbort']?.(what);
 #endif
 
   what = 'Aborted(' + what + ')';
@@ -762,9 +756,7 @@ function instantiateSync(file, info) {
       }
     }
   }
-  if (!module) {
-    module = new WebAssembly.Module(binary);
-  }
+  module ||= new WebAssembly.Module(binary);
   if (ENVIRONMENT_IS_NODE && !hasCached) {
 #if RUNTIME_DEBUG
     dbg('NODE_CODE_CACHING: saving module');
diff --git a/src/proxyClient.js b/src/proxyClient.js
index 80c7a3392e126..49c3f1c9eab81 100644
--- a/src/proxyClient.js
+++ b/src/proxyClient.js
@@ -134,9 +134,7 @@ var SUPPORT_BASE64_EMBEDDING;
 // Worker
 
 var filename;
-if (!filename) {
-  filename = '<<< filename >>>';
-}
+filename ||= '<<< filename >>>';
 
 var workerURL = filename;
 if (SUPPORT_BASE64_EMBEDDING) {
@@ -174,7 +172,7 @@ worker.onmessage = (event) => {
   //dump('\nclient got ' + JSON.stringify(event.data).substr(0, 150) + '\n');
   if (!workerResponded) {
     workerResponded = true;
-    if (Module.setStatus) Module.setStatus('');
+    Module.setStatus?.('');
     if (SUPPORT_BASE64_EMBEDDING && workerURL !== filename) URL.revokeObjectURL(workerURL);
   }
 
@@ -205,7 +203,7 @@ worker.onmessage = (event) => {
         case 'resize': {
           Module.canvas.width = data.width;
           Module.canvas.height = data.height;
-          if (Module.ctx && Module.ctx.getImageData) Module.canvasData = Module.ctx.getImageData(0, 0, data.width, data.height);
+          if (Module.ctx?.getImageData) Module.canvasData = Module.ctx.getImageData(0, 0, data.width, data.height);
           worker.postMessage({ target: 'canvas', boundingClientRect: cloneObject(Module.canvas.getBoundingClientRect()) });
           break;
         }
diff --git a/src/proxyWorker.js b/src/proxyWorker.js
index 341d85e26aa67..c48f5af7d15a5 100644
--- a/src/proxyWorker.js
+++ b/src/proxyWorker.js
@@ -65,7 +65,7 @@ function EventListener() {
   this.listeners = {};
 
   this.addEventListener = function addEventListener(event, func) {
-    if (!this.listeners[event]) this.listeners[event] = [];
+    this.listeners[event] ||= [];
     this.listeners[event].push(func);
   };
 
@@ -211,8 +211,8 @@ document.createElement = (what) => {
       canvas.style = new PropertyBag();
       canvas.exitPointerLock = () => {};
 
-      canvas.width_ = canvas.width_ || 0;
-      canvas.height_ = canvas.height_ || 0;
+      canvas.width_ ||= 0;
+      canvas.height_ ||= 0;
       Object.defineProperty(canvas, 'width', {
         set: (value) => {
           canvas.width_ = value;
@@ -344,7 +344,7 @@ var clientFrameId = 0;
 
 var postMainLoop = Module['postMainLoop'];
 Module['postMainLoop'] = () => {
-  if (postMainLoop) postMainLoop();
+  postMainLoop?.();
   // frame complete, send a frame id
   postMessage({ target: 'tick', id: frameId++ });
   commandBuffer = [];
@@ -372,7 +372,7 @@ var messageResenderTimeout = null;
 var calledMain = false;
 
 // Set calledMain to true during postRun which happens onces main returns
-if (!Module['postRun']) Module['postRun'] = [];
+Module['postRun'] ||= [];
 if (typeof Module['postRun'] == 'function') Module['postRun'] = [Module['postRun']];
 Module['postRun'].push(() => { calledMain = true; });
 
diff --git a/src/runtime_math.js b/src/runtime_math.js
index 9a14fd5afe5c9..6bc3658001682 100644
--- a/src/runtime_math.js
+++ b/src/runtime_math.js
@@ -27,7 +27,7 @@ if (!Math.fround) {
 
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/clz32
 #if POLYFILL_OLD_MATH_FUNCTIONS || MIN_CHROME_VERSION < 38 || MIN_EDGE_VERSION < 12 || MIN_FIREFOX_VERSION < 31 || MIN_IE_VERSION != TARGET_NOT_SUPPORTED // || MIN_NODE_VERSION < 0.12
-if (!Math.clz32) Math.clz32 = (x) => {
+Math.clz32 ||= (x) => {
   var n = 32;
   var y = x >> 16; if (y) { n -= 16; x = y; }
   y = x >> 8; if (y) { n -= 8; x = y; }
@@ -40,7 +40,7 @@ if (!Math.clz32) Math.clz32 = (x) => {
 
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/trunc
 #if POLYFILL_OLD_MATH_FUNCTIONS || MIN_CHROME_VERSION < 38 || MIN_EDGE_VERSION < 12 || MIN_FIREFOX_VERSION < 25 || MIN_IE_VERSION != TARGET_NOT_SUPPORTED || MIN_SAFARI_VERSION < 80000 // || MIN_NODE_VERSION < 0.12
-if (!Math.trunc) Math.trunc = (x) => {
+Math.trunc ||= (x) => {
   return x < 0 ? Math.ceil(x) : Math.floor(x);
 };
 #endif
diff --git a/src/settings.js b/src/settings.js
index 4109dcfbd80c6..5764f26d97f8c 100644
--- a/src/settings.js
+++ b/src/settings.js
@@ -1768,10 +1768,10 @@ var AUTO_NATIVE_LIBRARIES = true;
 // versions >= MIN_FIREFOX_VERSION
 // are desired to work. Pass -sMIN_FIREFOX_VERSION=majorVersion to drop support
 // for Firefox versions older than < majorVersion.
-// Firefox ESR 68 was released on July 9, 2019.
+// Firefox 79 was released on 2020-07-28.
 // MAX_INT (0x7FFFFFFF, or -1) specifies that target is not supported.
 // [link]
-var MIN_FIREFOX_VERSION = 68;
+var MIN_FIREFOX_VERSION = 79;
 
 // Specifies the oldest version of desktop Safari to target. Version is encoded
 // in MMmmVV, e.g. 70101 denotes Safari 7.1.1.
@@ -1810,10 +1810,10 @@ var MIN_EDGE_VERSION = 0x7FFFFFFF;
 
 // Specifies the oldest version of Chrome. E.g. pass -sMIN_CHROME_VERSION=58 to
 // drop support for Chrome 57 and older.
-// Chrome 75.0.3770 was released on 2019-06-04
+// Chrome 85 was released on 2020-08-25.
 // MAX_INT (0x7FFFFFFF, or -1) specifies that target is not supported.
 // [link]
-var MIN_CHROME_VERSION = 75;
+var MIN_CHROME_VERSION = 85;
 
 // Specifies minimum node version to target for the generated code.  This is
 // distinct from the minimum version required run the emscripten compiler.
diff --git a/src/utility.js b/src/utility.js
index 062559ce37f46..b0919790b9de6 100644
--- a/src/utility.js
+++ b/src/utility.js
@@ -67,7 +67,7 @@ function warnOnce(a, msg) {
     a = false;
   }
   if (!a) {
-    if (!warnOnce.msgs) warnOnce.msgs = {};
+    warnOnce.msgs ||= {};
     if (msg in warnOnce.msgs) return;
     warnOnce.msgs[msg] = true;
     warn(msg);
@@ -247,7 +247,7 @@ function Benchmarker() {
     }
     lastTime = now;
     ids.push(id);
-    totals[id] = totals[id] || 0;
+    totals[id] ||= 0;
   };
   this.stop = function(id) {
     const now = Date.now();
diff --git a/src/worker.js b/src/worker.js
index 2fbadcfa61991..3a863ffaf0ef2 100644
--- a/src/worker.js
+++ b/src/worker.js
@@ -271,11 +271,9 @@ function handleMessage(e) {
   } catch(ex) {
 #if ASSERTIONS
     err(`worker.js onmessage() captured an uncaught exception: ${ex}`);
-    if (ex && ex.stack) err(ex.stack);
+    if (ex?.stack) err(ex.stack);
 #endif
-    if (Module['__emscripten_thread_crashed']) {
-      Module['__emscripten_thread_crashed']();
-    }
+    Module['__emscripten_thread_crashed']?.();
     throw ex;
   }
 };
diff --git a/test/code_size/hello_webgl2_wasm.json b/test/code_size/hello_webgl2_wasm.json
index ec49d4dc16710..d2a834be28519 100644
--- a/test/code_size/hello_webgl2_wasm.json
+++ b/test/code_size/hello_webgl2_wasm.json
@@ -1,10 +1,10 @@
 {
   "a.html": 569,
   "a.html.gz": 379,
-  "a.js": 4700,
+  "a.js": 4698,
   "a.js.gz": 2417,
   "a.wasm": 10467,
   "a.wasm.gz": 6706,
-  "total": 15736,
+  "total": 15734,
   "total_gz": 9502
 }
diff --git a/test/code_size/hello_webgl2_wasm2js.json b/test/code_size/hello_webgl2_wasm2js.json
index 4122c5c210f7f..e1392aadbf5e6 100644
--- a/test/code_size/hello_webgl2_wasm2js.json
+++ b/test/code_size/hello_webgl2_wasm2js.json
@@ -1,10 +1,10 @@
 {
   "a.html": 567,
   "a.html.gz": 379,
-  "a.js": 17913,
-  "a.js.gz": 8063,
+  "a.js": 17910,
+  "a.js.gz": 8064,
   "a.mem": 3171,
   "a.mem.gz": 2713,
-  "total": 21651,
-  "total_gz": 11155
+  "total": 21648,
+  "total_gz": 11156
 }
diff --git a/test/code_size/hello_webgl_wasm.json b/test/code_size/hello_webgl_wasm.json
index c8b509c537ba2..a0db530fedb04 100644
--- a/test/code_size/hello_webgl_wasm.json
+++ b/test/code_size/hello_webgl_wasm.json
@@ -1,10 +1,10 @@
 {
   "a.html": 569,
   "a.html.gz": 379,
-  "a.js": 4186,
-  "a.js.gz": 2244,
+  "a.js": 4184,
+  "a.js.gz": 2242,
   "a.wasm": 10467,
   "a.wasm.gz": 6706,
-  "total": 15222,
-  "total_gz": 9329
+  "total": 15220,
+  "total_gz": 9327
 }
diff --git a/test/code_size/hello_webgl_wasm2js.json b/test/code_size/hello_webgl_wasm2js.json
index fda6e750793f0..133af5e84692a 100644
--- a/test/code_size/hello_webgl_wasm2js.json
+++ b/test/code_size/hello_webgl_wasm2js.json
@@ -1,10 +1,10 @@
 {
   "a.html": 567,
   "a.html.gz": 379,
-  "a.js": 17391,
-  "a.js.gz": 7890,
+  "a.js": 17388,
+  "a.js.gz": 7887,
   "a.mem": 3171,
   "a.mem.gz": 2713,
-  "total": 21129,
-  "total_gz": 10982
+  "total": 21126,
+  "total_gz": 10979
 }
diff --git a/test/other/test_unoptimized_code_size.js.size b/test/other/test_unoptimized_code_size.js.size
index 59516e21ec507..70bb62401f9ad 100644
--- a/test/other/test_unoptimized_code_size.js.size
+++ b/test/other/test_unoptimized_code_size.js.size
@@ -1 +1 @@
-58305
+59815
diff --git a/test/other/test_unoptimized_code_size_no_asserts.js.size b/test/other/test_unoptimized_code_size_no_asserts.js.size
index f90fb8fd192b6..442711b3ea4c7 100644
--- a/test/other/test_unoptimized_code_size_no_asserts.js.size
+++ b/test/other/test_unoptimized_code_size_no_asserts.js.size
@@ -1 +1 @@
-31702
+32503
diff --git a/test/other/test_unoptimized_code_size_strict.js.size b/test/other/test_unoptimized_code_size_strict.js.size
index f7b4552c30211..1e88428ebf643 100644
--- a/test/other/test_unoptimized_code_size_strict.js.size
+++ b/test/other/test_unoptimized_code_size_strict.js.size
@@ -1 +1 @@
-57018
+58622
diff --git a/tools/acorn-optimizer.js b/tools/acorn-optimizer.js
index 8260ec601112b..2d97919f7959c 100755
--- a/tools/acorn-optimizer.js
+++ b/tools/acorn-optimizer.js
@@ -1044,7 +1044,7 @@ function applyDCEGraphRemovals(ast) {
 
 // Need a parser to pass to acorn.Node constructor.
 // Create it once and reuse it.
-const stubParser = new acorn.Parser({ecmaVersion: 2020});
+const stubParser = new acorn.Parser({ecmaVersion: 2021});
 
 function createNode(props) {
   const node = new acorn.Node(stubParser);
@@ -2008,7 +2008,7 @@ let ast;
 try {
   ast = acorn.parse(input, {
     // Keep in sync with --language_in that we pass to closure in building.py
-    ecmaVersion: 2020,
+    ecmaVersion: 2021,
     preserveParens: closureFriendly,
     onComment: closureFriendly ? sourceComments : undefined,
     sourceType: exportES6 ? 'module' : 'script',
diff --git a/tools/building.py b/tools/building.py
index 7f063bffb07c1..c24f1c41c6fdf 100644
--- a/tools/building.py
+++ b/tools/building.py
@@ -567,7 +567,7 @@ def closure_compiler(filename, advanced=True, extra_closure_args=None):
 
   args = ['--compilation_level', 'ADVANCED_OPTIMIZATIONS' if advanced else 'SIMPLE_OPTIMIZATIONS']
   # Keep in sync with ecmaVersion in tools/acorn-optimizer.js
-  args += ['--language_in', 'ECMASCRIPT_2020']
+  args += ['--language_in', 'ECMASCRIPT_2021']
   # Tell closure not to do any transpiling or inject any polyfills.
   # At some point we may want to look into using this as way to convert to ES5 but
   # babel is perhaps a better tool for that.
diff --git a/tools/unsafe_optimizations.js b/tools/unsafe_optimizations.js
index 41641f93499d3..45e8d01c3545b 100644
--- a/tools/unsafe_optimizations.js
+++ b/tools/unsafe_optimizations.js
@@ -223,7 +223,7 @@ function optPassMergeVarInitializationAssignments(ast) {
 }
 
 function runOnJsText(js, pretty = false) {
-  const ast = acorn.parse(js, {ecmaVersion: 2020});
+  const ast = acorn.parse(js, {ecmaVersion: 2021});
 
   optPassSimplifyModuleInitialization(ast);
   optPassRemoveRedundantOperatorNews(ast);