diff --git a/lectures/week_12-web-sockets/code/completed/package-lock.json b/lectures/week_12-web-sockets/code/completed/package-lock.json
index 7b3b2181..e0623e91 100644
--- a/lectures/week_12-web-sockets/code/completed/package-lock.json
+++ b/lectures/week_12-web-sockets/code/completed/package-lock.json
@@ -4,6 +4,26 @@
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
+    "@socket.io/component-emitter": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/@socket.io/component-emitter/-/component-emitter-3.1.0.tgz",
+      "integrity": "sha512-+9jVqKhRSpsc591z5vX+X5Yyw+he/HCB4iQ/RYxw35CEPaY1gnsNE43nf9n9AaYjAQrTiI/mOwKUKdUs9vf7Xg=="
+    },
+    "@types/cookie": {
+      "version": "0.4.1",
+      "resolved": "https://registry.npmjs.org/@types/cookie/-/cookie-0.4.1.tgz",
+      "integrity": "sha512-XW/Aa8APYr6jSVVA1y/DEIZX0/GMKLEVekNG727R8cs56ahETkRAy/3DR7+fJyh7oUgGwNQaRfXCun0+KbWY7Q=="
+    },
+    "@types/cors": {
+      "version": "2.8.12",
+      "resolved": "https://registry.npmjs.org/@types/cors/-/cors-2.8.12.tgz",
+      "integrity": "sha512-vt+kDhq/M2ayberEtJcIN/hxXy1Pk+59g2FV/ZQceeaTyCtCucjL2Q7FXlFjtWn4n15KCr1NE2lNNFhp0lEThw=="
+    },
+    "@types/node": {
+      "version": "18.11.9",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-18.11.9.tgz",
+      "integrity": "sha512-CRpX21/kGdzjOpFsZSkcrXMGIBWMGNIHXXBVFSH+ggkftxg+XYP20TESbh+zFvFj3EQOl5byk0HTRn1IL6hbqg=="
+    },
     "accepts": {
       "version": "1.3.7",
       "resolved": "https://registry.npmjs.org/accepts/-/accepts-1.3.7.tgz",
@@ -13,21 +33,11 @@
         "negotiator": "0.6.2"
       }
     },
-    "after": {
-      "version": "0.8.2",
-      "resolved": "https://registry.npmjs.org/after/-/after-0.8.2.tgz",
-      "integrity": "sha1-/ts5T58OAqqXaOcCvaI7UF+ufh8="
-    },
     "array-flatten": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/array-flatten/-/array-flatten-1.1.1.tgz",
       "integrity": "sha1-ml9pkFGx5wczKPKgCJaLZOopVdI="
     },
-    "arraybuffer.slice": {
-      "version": "0.0.6",
-      "resolved": "https://registry.npmjs.org/arraybuffer.slice/-/arraybuffer.slice-0.0.6.tgz",
-      "integrity": "sha1-8zshWfBTKj8xB6JywMz70a0peco="
-    },
     "asap": {
       "version": "2.0.6",
       "resolved": "https://registry.npmjs.org/asap/-/asap-2.0.6.tgz",
@@ -41,38 +51,15 @@
         "lodash": "^4.14.0"
       }
     },
-    "backo2": {
-      "version": "1.0.2",
-      "resolved": "https://registry.npmjs.org/backo2/-/backo2-1.0.2.tgz",
-      "integrity": "sha1-MasayLEpNjRj41s+u2n038+6eUc="
-    },
     "balanced-match": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-1.0.0.tgz",
       "integrity": "sha1-ibTRmasr7kneFk6gK4nORi1xt2c="
     },
-    "base64-arraybuffer": {
-      "version": "0.1.5",
-      "resolved": "https://registry.npmjs.org/base64-arraybuffer/-/base64-arraybuffer-0.1.5.tgz",
-      "integrity": "sha1-c5JncZI7Whl0etZmqlzUv5xunOg="
-    },
     "base64id": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/base64id/-/base64id-1.0.0.tgz",
-      "integrity": "sha1-R2iMuZu2gE8OBtPnY7HDLlfY5rY="
-    },
-    "better-assert": {
-      "version": "1.0.2",
-      "resolved": "https://registry.npmjs.org/better-assert/-/better-assert-1.0.2.tgz",
-      "integrity": "sha1-QIZrnhueC1W0gYlDEeaPr/rrxSI=",
-      "requires": {
-        "callsite": "1.0.0"
-      }
-    },
-    "blob": {
-      "version": "0.0.4",
-      "resolved": "https://registry.npmjs.org/blob/-/blob-0.0.4.tgz",
-      "integrity": "sha1-vPEwUspURj8w+fx+lbmkdjCpSSE="
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/base64id/-/base64id-2.0.0.tgz",
+      "integrity": "sha512-lGe34o6EHj9y3Kts9R4ZYs/Gr+6N7MCaMlIFA3F1R2O5/m7K06AxfSeO5530PEERE6/WyEg3lsuyw4GHlPZHog=="
     },
     "bluebird": {
       "version": "3.5.0",
@@ -120,32 +107,12 @@
       "resolved": "https://registry.npmjs.org/bytes/-/bytes-3.1.0.tgz",
       "integrity": "sha512-zauLjrfCG+xvoyaqLoV8bLVXXNGC4JqlxFCutSDWA6fJrTo2ZuvLYTqZ7aHBLZSMOopbzwv8f+wZcVzfVTI2Dg=="
     },
-    "callsite": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/callsite/-/callsite-1.0.0.tgz",
-      "integrity": "sha1-KAOY5dZkvXQDi28JBRU+borxvCA="
-    },
     "commander": {
       "version": "2.20.3",
       "resolved": "https://registry.npmjs.org/commander/-/commander-2.20.3.tgz",
       "integrity": "sha512-GpVkmM8vF2vQUkj2LvZmD35JxeJOLCwJ9cUkugyk2nuhbv3+mJvpLYYt+0+USMxE+oj+ey/lJEnhZw75x/OMcQ==",
       "optional": true
     },
-    "component-bind": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/component-bind/-/component-bind-1.0.0.tgz",
-      "integrity": "sha1-AMYIq33Nk4l8AAllGx06jh5zu9E="
-    },
-    "component-emitter": {
-      "version": "1.1.2",
-      "resolved": "https://registry.npmjs.org/component-emitter/-/component-emitter-1.1.2.tgz",
-      "integrity": "sha1-KWWU8nU9qmOZbSrwjRWpURbJrsM="
-    },
-    "component-inherit": {
-      "version": "0.0.3",
-      "resolved": "https://registry.npmjs.org/component-inherit/-/component-inherit-0.0.3.tgz",
-      "integrity": "sha1-ZF/ErfWLcrZJ1crmUTVhnbJv8UM="
-    },
     "concat-map": {
       "version": "0.0.1",
       "resolved": "https://registry.npmjs.org/concat-map/-/concat-map-0.0.1.tgz",
@@ -179,6 +146,15 @@
       "resolved": "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.2.tgz",
       "integrity": "sha1-tf1UIgqivFq1eqtxQMlAdUUDwac="
     },
+    "cors": {
+      "version": "2.8.5",
+      "resolved": "https://registry.npmjs.org/cors/-/cors-2.8.5.tgz",
+      "integrity": "sha512-KIHbLJqu73RGr/hnbrO9uBeixNGuvSQjul/jdFvS/KFSIH1hWVd1ng7zOHx+YrEfInLG7q4n6GHQ9cDtxv/P6g==",
+      "requires": {
+        "object-assign": "^4",
+        "vary": "^1"
+      }
+    },
     "debug": {
       "version": "2.6.9",
       "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
@@ -221,103 +197,46 @@
       "integrity": "sha1-rT/0yG7C0CkyL1oCw6mmBslbP1k="
     },
     "engine.io": {
-      "version": "1.8.5",
-      "resolved": "https://registry.npmjs.org/engine.io/-/engine.io-1.8.5.tgz",
-      "integrity": "sha512-j1DWIcktw4hRwrv6nWx++5nFH2X64x16MAG2P0Lmi5Dvdfi3I+Jhc7JKJIdAmDJa+5aZ/imHV7dWRPy2Cqjh3A==",
-      "requires": {
-        "accepts": "1.3.3",
-        "base64id": "1.0.0",
-        "cookie": "0.3.1",
-        "debug": "2.3.3",
-        "engine.io-parser": "1.3.2",
-        "ws": "~1.1.5"
+      "version": "6.2.1",
+      "resolved": "https://registry.npmjs.org/engine.io/-/engine.io-6.2.1.tgz",
+      "integrity": "sha512-ECceEFcAaNRybd3lsGQKas3ZlMVjN3cyWwMP25D2i0zWfyiytVbTpRPa34qrr+FHddtpBVOmq4H/DCv1O0lZRA==",
+      "requires": {
+        "@types/cookie": "^0.4.1",
+        "@types/cors": "^2.8.12",
+        "@types/node": ">=10.0.0",
+        "accepts": "~1.3.4",
+        "base64id": "2.0.0",
+        "cookie": "~0.4.1",
+        "cors": "~2.8.5",
+        "debug": "~4.3.1",
+        "engine.io-parser": "~5.0.3",
+        "ws": "~8.2.3"
       },
       "dependencies": {
-        "accepts": {
-          "version": "1.3.3",
-          "resolved": "https://registry.npmjs.org/accepts/-/accepts-1.3.3.tgz",
-          "integrity": "sha1-w8p0NJOGSMPg2cHjKN1otiLChMo=",
-          "requires": {
-            "mime-types": "~2.1.11",
-            "negotiator": "0.6.1"
-          }
-        },
         "cookie": {
-          "version": "0.3.1",
-          "resolved": "https://registry.npmjs.org/cookie/-/cookie-0.3.1.tgz",
-          "integrity": "sha1-5+Ch+e9DtMi6klxcWpboBtFoc7s="
+          "version": "0.4.2",
+          "resolved": "https://registry.npmjs.org/cookie/-/cookie-0.4.2.tgz",
+          "integrity": "sha512-aSWTXFzaKWkvHO1Ny/s+ePFpvKsPnjc551iI41v3ny/ow6tBG5Vd+FuqGNhh1LxOmVzOlGUriIlOaokOvhaStA=="
         },
         "debug": {
-          "version": "2.3.3",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-2.3.3.tgz",
-          "integrity": "sha1-QMRT5n5uE8kB3ewxeviYbNqe/4w=",
+          "version": "4.3.4",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.4.tgz",
+          "integrity": "sha512-PRWFHuSU3eDtQJPvnNY7Jcket1j0t5OuOsFzPPzsekD52Zl8qUfFIPEiswXqIvHWGVHOgX+7G/vCNNhehwxfkQ==",
           "requires": {
-            "ms": "0.7.2"
+            "ms": "2.1.2"
           }
         },
         "ms": {
-          "version": "0.7.2",
-          "resolved": "https://registry.npmjs.org/ms/-/ms-0.7.2.tgz",
-          "integrity": "sha1-riXPJRKziFodldfwN4aNhDESR2U="
-        },
-        "negotiator": {
-          "version": "0.6.1",
-          "resolved": "https://registry.npmjs.org/negotiator/-/negotiator-0.6.1.tgz",
-          "integrity": "sha1-KzJxhOiZIQEXeyhWP7XnECrNDKk="
-        }
-      }
-    },
-    "engine.io-client": {
-      "version": "1.8.5",
-      "resolved": "https://registry.npmjs.org/engine.io-client/-/engine.io-client-1.8.5.tgz",
-      "integrity": "sha512-AYTgHyeVUPitsseqjoedjhYJapNVoSPShbZ+tEUX9/73jgZ/Z3sUlJf9oYgdEBBdVhupUpUqSxH0kBCXlQnmZg==",
-      "requires": {
-        "component-emitter": "1.2.1",
-        "component-inherit": "0.0.3",
-        "debug": "2.3.3",
-        "engine.io-parser": "1.3.2",
-        "has-cors": "1.1.0",
-        "indexof": "0.0.1",
-        "parsejson": "0.0.3",
-        "parseqs": "0.0.5",
-        "parseuri": "0.0.5",
-        "ws": "~1.1.5",
-        "xmlhttprequest-ssl": "1.5.3",
-        "yeast": "0.1.2"
-      },
-      "dependencies": {
-        "component-emitter": {
-          "version": "1.2.1",
-          "resolved": "https://registry.npmjs.org/component-emitter/-/component-emitter-1.2.1.tgz",
-          "integrity": "sha1-E3kY1teCg/ffemt8WmPhQOaUJeY="
-        },
-        "debug": {
-          "version": "2.3.3",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-2.3.3.tgz",
-          "integrity": "sha1-QMRT5n5uE8kB3ewxeviYbNqe/4w=",
-          "requires": {
-            "ms": "0.7.2"
-          }
-        },
-        "ms": {
-          "version": "0.7.2",
-          "resolved": "https://registry.npmjs.org/ms/-/ms-0.7.2.tgz",
-          "integrity": "sha1-riXPJRKziFodldfwN4aNhDESR2U="
+          "version": "2.1.2",
+          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
+          "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w=="
         }
       }
     },
     "engine.io-parser": {
-      "version": "1.3.2",
-      "resolved": "https://registry.npmjs.org/engine.io-parser/-/engine.io-parser-1.3.2.tgz",
-      "integrity": "sha1-k3sHnwAH0Ik+xW1GyyILjLQ1Igo=",
-      "requires": {
-        "after": "0.8.2",
-        "arraybuffer.slice": "0.0.6",
-        "base64-arraybuffer": "0.1.5",
-        "blob": "0.0.4",
-        "has-binary": "0.1.7",
-        "wtf-8": "1.0.0"
-      }
+      "version": "5.0.4",
+      "resolved": "https://registry.npmjs.org/engine.io-parser/-/engine.io-parser-5.0.4.tgz",
+      "integrity": "sha512-+nVFp+5z1E3HcToEnO7ZIj3g+3k9389DvWtvJZz0T6/eOCPIyyxehFcedoYrZQrp0LgQbD9pPXhpMBKMd5QURg=="
     },
     "es6-promise": {
       "version": "3.2.1",
@@ -446,26 +365,6 @@
         "uglify-js": "^3.1.4"
       }
     },
-    "has-binary": {
-      "version": "0.1.7",
-      "resolved": "https://registry.npmjs.org/has-binary/-/has-binary-0.1.7.tgz",
-      "integrity": "sha1-aOYesWIQyVRaClzOBqhzkS/h5ow=",
-      "requires": {
-        "isarray": "0.0.1"
-      },
-      "dependencies": {
-        "isarray": {
-          "version": "0.0.1",
-          "resolved": "https://registry.npmjs.org/isarray/-/isarray-0.0.1.tgz",
-          "integrity": "sha1-ihis/Kmo9Bd+Cav8YDiTmwXR7t8="
-        }
-      }
-    },
-    "has-cors": {
-      "version": "1.1.0",
-      "resolved": "https://registry.npmjs.org/has-cors/-/has-cors-1.1.0.tgz",
-      "integrity": "sha1-XkdHk/fqmEPRu5nCPu9J/xJv/zk="
-    },
     "has-symbols": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/has-symbols/-/has-symbols-1.0.0.tgz",
@@ -496,11 +395,6 @@
         "safer-buffer": ">= 2.1.2 < 3"
       }
     },
-    "indexof": {
-      "version": "0.0.1",
-      "resolved": "https://registry.npmjs.org/indexof/-/indexof-0.0.1.tgz",
-      "integrity": "sha1-gtwzbSMrkGIXnQWrMpOmYFn9Q10="
-    },
     "inflight": {
       "version": "1.0.6",
       "resolved": "https://registry.npmjs.org/inflight/-/inflight-1.0.6.tgz",
@@ -525,11 +419,6 @@
       "resolved": "https://registry.npmjs.org/isarray/-/isarray-1.0.0.tgz",
       "integrity": "sha1-u5NdSFgsuhaMBoNJV6VKPgcSTxE="
     },
-    "json3": {
-      "version": "3.3.2",
-      "resolved": "https://registry.npmjs.org/json3/-/json3-3.3.2.tgz",
-      "integrity": "sha1-PAQ0dD35Pi9cQq7nsZvLSDV19OE="
-    },
     "kareem": {
       "version": "1.5.0",
       "resolved": "https://registry.npmjs.org/kareem/-/kareem-1.5.0.tgz",
@@ -679,14 +568,9 @@
       "integrity": "sha512-iyam8fBuCUpWeKPGpaNMetEocMt364qkCsfL9JuhjXX6dRnguRVOfk2GZaDpPjcOKiiXCPINZC1GczQ7iTq3Zw=="
     },
     "object-assign": {
-      "version": "4.1.0",
-      "resolved": "https://registry.npmjs.org/object-assign/-/object-assign-4.1.0.tgz",
-      "integrity": "sha1-ejs9DpgGPUP0wD8uiubNUahog6A="
-    },
-    "object-component": {
-      "version": "0.0.3",
-      "resolved": "https://registry.npmjs.org/object-component/-/object-component-0.0.3.tgz",
-      "integrity": "sha1-8MaapQ78lbhmwYb0AKM3acsvEpE="
+      "version": "4.1.1",
+      "resolved": "https://registry.npmjs.org/object-assign/-/object-assign-4.1.1.tgz",
+      "integrity": "sha512-rJgTQnkUnH1sFw8yT6VSU3zD3sWmu6sZhIseY8VX+GRu3P6F7Fu+JNDoXfklElbLJSnc3FUQHVe4cU5hj+BcUg=="
     },
     "object-keys": {
       "version": "1.1.1",
@@ -729,35 +613,6 @@
         "wordwrap": "~0.0.2"
       }
     },
-    "options": {
-      "version": "0.0.6",
-      "resolved": "https://registry.npmjs.org/options/-/options-0.0.6.tgz",
-      "integrity": "sha1-7CLTEoBrtT5zF3Pnza788cZDEo8="
-    },
-    "parsejson": {
-      "version": "0.0.3",
-      "resolved": "https://registry.npmjs.org/parsejson/-/parsejson-0.0.3.tgz",
-      "integrity": "sha1-q343WfIJ7OmUN5c/fQ8fZK4OZKs=",
-      "requires": {
-        "better-assert": "~1.0.0"
-      }
-    },
-    "parseqs": {
-      "version": "0.0.5",
-      "resolved": "https://registry.npmjs.org/parseqs/-/parseqs-0.0.5.tgz",
-      "integrity": "sha1-1SCKNzjkZ2bikbouoXNoSSGouJ0=",
-      "requires": {
-        "better-assert": "~1.0.0"
-      }
-    },
-    "parseuri": {
-      "version": "0.0.5",
-      "resolved": "https://registry.npmjs.org/parseuri/-/parseuri-0.0.5.tgz",
-      "integrity": "sha1-gCBKUNTbt3m/3G6+J3jZDkvOMgo=",
-      "requires": {
-        "better-assert": "~1.0.0"
-      }
-    },
     "parseurl": {
       "version": "1.3.3",
       "resolved": "https://registry.npmjs.org/parseurl/-/parseurl-1.3.3.tgz",
@@ -913,124 +768,59 @@
       "integrity": "sha1-CzpmK10Ewxd7GSa+qCsD+Dei70E="
     },
     "socket.io": {
-      "version": "1.7.4",
-      "resolved": "https://registry.npmjs.org/socket.io/-/socket.io-1.7.4.tgz",
-      "integrity": "sha1-L37O3DORvy1cc+KR/iM+bjTU3QA=",
-      "requires": {
-        "debug": "2.3.3",
-        "engine.io": "~1.8.4",
-        "has-binary": "0.1.7",
-        "object-assign": "4.1.0",
-        "socket.io-adapter": "0.5.0",
-        "socket.io-client": "1.7.4",
-        "socket.io-parser": "2.3.1"
+      "version": "4.5.3",
+      "resolved": "https://registry.npmjs.org/socket.io/-/socket.io-4.5.3.tgz",
+      "integrity": "sha512-zdpnnKU+H6mOp7nYRXH4GNv1ux6HL6+lHL8g7Ds7Lj8CkdK1jJK/dlwsKDculbyOHifcJ0Pr/yeXnZQ5GeFrcg==",
+      "requires": {
+        "accepts": "~1.3.4",
+        "base64id": "~2.0.0",
+        "debug": "~4.3.2",
+        "engine.io": "~6.2.0",
+        "socket.io-adapter": "~2.4.0",
+        "socket.io-parser": "~4.2.0"
       },
       "dependencies": {
         "debug": {
-          "version": "2.3.3",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-2.3.3.tgz",
-          "integrity": "sha1-QMRT5n5uE8kB3ewxeviYbNqe/4w=",
+          "version": "4.3.4",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.4.tgz",
+          "integrity": "sha512-PRWFHuSU3eDtQJPvnNY7Jcket1j0t5OuOsFzPPzsekD52Zl8qUfFIPEiswXqIvHWGVHOgX+7G/vCNNhehwxfkQ==",
           "requires": {
-            "ms": "0.7.2"
+            "ms": "2.1.2"
           }
         },
         "ms": {
-          "version": "0.7.2",
-          "resolved": "https://registry.npmjs.org/ms/-/ms-0.7.2.tgz",
-          "integrity": "sha1-riXPJRKziFodldfwN4aNhDESR2U="
+          "version": "2.1.2",
+          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
+          "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w=="
         }
       }
     },
     "socket.io-adapter": {
-      "version": "0.5.0",
-      "resolved": "https://registry.npmjs.org/socket.io-adapter/-/socket.io-adapter-0.5.0.tgz",
-      "integrity": "sha1-y21LuL7IHhB4uZZ3+c7QBGBmu4s=",
-      "requires": {
-        "debug": "2.3.3",
-        "socket.io-parser": "2.3.1"
-      },
-      "dependencies": {
-        "debug": {
-          "version": "2.3.3",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-2.3.3.tgz",
-          "integrity": "sha1-QMRT5n5uE8kB3ewxeviYbNqe/4w=",
-          "requires": {
-            "ms": "0.7.2"
-          }
-        },
-        "ms": {
-          "version": "0.7.2",
-          "resolved": "https://registry.npmjs.org/ms/-/ms-0.7.2.tgz",
-          "integrity": "sha1-riXPJRKziFodldfwN4aNhDESR2U="
-        }
-      }
-    },
-    "socket.io-client": {
-      "version": "1.7.4",
-      "resolved": "https://registry.npmjs.org/socket.io-client/-/socket.io-client-1.7.4.tgz",
-      "integrity": "sha1-7J+CA1btme9tNX8HVtZIcXvdQoE=",
-      "requires": {
-        "backo2": "1.0.2",
-        "component-bind": "1.0.0",
-        "component-emitter": "1.2.1",
-        "debug": "2.3.3",
-        "engine.io-client": "~1.8.4",
-        "has-binary": "0.1.7",
-        "indexof": "0.0.1",
-        "object-component": "0.0.3",
-        "parseuri": "0.0.5",
-        "socket.io-parser": "2.3.1",
-        "to-array": "0.1.4"
-      },
-      "dependencies": {
-        "component-emitter": {
-          "version": "1.2.1",
-          "resolved": "https://registry.npmjs.org/component-emitter/-/component-emitter-1.2.1.tgz",
-          "integrity": "sha1-E3kY1teCg/ffemt8WmPhQOaUJeY="
-        },
-        "debug": {
-          "version": "2.3.3",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-2.3.3.tgz",
-          "integrity": "sha1-QMRT5n5uE8kB3ewxeviYbNqe/4w=",
-          "requires": {
-            "ms": "0.7.2"
-          }
-        },
-        "ms": {
-          "version": "0.7.2",
-          "resolved": "https://registry.npmjs.org/ms/-/ms-0.7.2.tgz",
-          "integrity": "sha1-riXPJRKziFodldfwN4aNhDESR2U="
-        }
-      }
+      "version": "2.4.0",
+      "resolved": "https://registry.npmjs.org/socket.io-adapter/-/socket.io-adapter-2.4.0.tgz",
+      "integrity": "sha512-W4N+o69rkMEGVuk2D/cvca3uYsvGlMwsySWV447y99gUPghxq42BxqLNMndb+a1mm/5/7NeXVQS7RLa2XyXvYg=="
     },
     "socket.io-parser": {
-      "version": "2.3.1",
-      "resolved": "https://registry.npmjs.org/socket.io-parser/-/socket.io-parser-2.3.1.tgz",
-      "integrity": "sha1-3VMgJRA85Clpcya+/WQAX8/ltKA=",
+      "version": "4.2.1",
+      "resolved": "https://registry.npmjs.org/socket.io-parser/-/socket.io-parser-4.2.1.tgz",
+      "integrity": "sha512-V4GrkLy+HeF1F/en3SpUaM+7XxYXpuMUWLGde1kSSh5nQMN4hLrbPIkD+otwh6q9R6NOQBN4AMaOZ2zVjui82g==",
       "requires": {
-        "component-emitter": "1.1.2",
-        "debug": "2.2.0",
-        "isarray": "0.0.1",
-        "json3": "3.3.2"
+        "@socket.io/component-emitter": "~3.1.0",
+        "debug": "~4.3.1"
       },
       "dependencies": {
         "debug": {
-          "version": "2.2.0",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-2.2.0.tgz",
-          "integrity": "sha1-+HBX6ZWxofauaklgZkE3vFbwOdo=",
+          "version": "4.3.4",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.4.tgz",
+          "integrity": "sha512-PRWFHuSU3eDtQJPvnNY7Jcket1j0t5OuOsFzPPzsekD52Zl8qUfFIPEiswXqIvHWGVHOgX+7G/vCNNhehwxfkQ==",
           "requires": {
-            "ms": "0.7.1"
+            "ms": "2.1.2"
           }
         },
-        "isarray": {
-          "version": "0.0.1",
-          "resolved": "https://registry.npmjs.org/isarray/-/isarray-0.0.1.tgz",
-          "integrity": "sha1-ihis/Kmo9Bd+Cav8YDiTmwXR7t8="
-        },
         "ms": {
-          "version": "0.7.1",
-          "resolved": "https://registry.npmjs.org/ms/-/ms-0.7.1.tgz",
-          "integrity": "sha1-nNE8A62/8ltl7/3nzoZO6VIBcJg="
+          "version": "2.1.2",
+          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
+          "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w=="
         }
       }
     },
@@ -1052,11 +842,6 @@
         "safe-buffer": "~5.1.0"
       }
     },
-    "to-array": {
-      "version": "0.1.4",
-      "resolved": "https://registry.npmjs.org/to-array/-/to-array-0.1.4.tgz",
-      "integrity": "sha1-F+bBH3PdTz10zaek/zI46a2b+JA="
-    },
     "toidentifier": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/toidentifier/-/toidentifier-1.0.0.tgz",
@@ -1081,11 +866,6 @@
         "source-map": "~0.6.1"
       }
     },
-    "ultron": {
-      "version": "1.0.2",
-      "resolved": "https://registry.npmjs.org/ultron/-/ultron-1.0.2.tgz",
-      "integrity": "sha1-rOEWq1V80Zc4ak6I9GhTeMiy5Po="
-    },
     "unpipe": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/unpipe/-/unpipe-1.0.0.tgz",
@@ -1117,28 +897,9 @@
       "integrity": "sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8="
     },
     "ws": {
-      "version": "1.1.5",
-      "resolved": "https://registry.npmjs.org/ws/-/ws-1.1.5.tgz",
-      "integrity": "sha512-o3KqipXNUdS7wpQzBHSe180lBGO60SoK0yVo3CYJgb2MkobuWuBX6dhkYP5ORCLd55y+SaflMOV5fqAB53ux4w==",
-      "requires": {
-        "options": ">=0.0.5",
-        "ultron": "1.0.x"
-      }
-    },
-    "wtf-8": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/wtf-8/-/wtf-8-1.0.0.tgz",
-      "integrity": "sha1-OS2LotDxw00e4tYw8V0O+2jhBIo="
-    },
-    "xmlhttprequest-ssl": {
-      "version": "1.5.3",
-      "resolved": "https://registry.npmjs.org/xmlhttprequest-ssl/-/xmlhttprequest-ssl-1.5.3.tgz",
-      "integrity": "sha1-GFqIjATspGw+QHDZn3tJ3jUomS0="
-    },
-    "yeast": {
-      "version": "0.1.2",
-      "resolved": "https://registry.npmjs.org/yeast/-/yeast-0.1.2.tgz",
-      "integrity": "sha1-AI4G2AlDIMNy28L47XagymyKxBk="
+      "version": "8.2.3",
+      "resolved": "https://registry.npmjs.org/ws/-/ws-8.2.3.tgz",
+      "integrity": "sha512-wBuoj1BDpC6ZQ1B7DWQBYVLphPWkm8i9Y0/3YdHjHKHiohOJ1ws+3OccDWtH+PoC9DZD5WOTrJvNbWvjS6JWaA=="
     }
   }
 }
diff --git a/lectures/week_12-web-sockets/code/completed/package.json b/lectures/week_12-web-sockets/code/completed/package.json
index 778b6a7e..cdb5b560 100644
--- a/lectures/week_12-web-sockets/code/completed/package.json
+++ b/lectures/week_12-web-sockets/code/completed/package.json
@@ -14,7 +14,7 @@
     "express": "^4.14.1",
     "express-handlebars": "^3.0.0",
     "mongoose": "^4.9.5",
-    "socket.io": "^1.7.3"
+    "socket.io": "^4.5.3"
   },
   "description": ""
 }