diff --git a/README.md b/README.md
index 14c421ab44..05d1560f0b 100644
--- a/README.md
+++ b/README.md
@@ -32,17 +32,13 @@ Please note that doing this will disable the test suite, so you will need to run
 cd scripts\
 bash test.sh
 
-## For Testing of js-slang
+## js-slang
 
-### Alpha version
-
-Use branch js-slang-alpha-preview to see the new changes (native and verbose errors).
-
-Have `"enable verbose";` as the first line of your program to activate verbose messages.
+Currently using a version of js-slang with native and verbose errors.
 
 Edit https://github.com/source-academy/cadet-frontend/blob/57ba44f6b55c214d0f20339cd45bece57f24f48c/src/sagas/index.ts#L260
 
-to toggle native.
+to toggle native (default is native enabled). 
 
 ### To run local copy of js-slang
 
diff --git a/package-lock.json b/package-lock.json
index cb6a25c5c9..e05cc3c194 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -342,12 +342,12 @@
       "dev": true
     },
     "@types/dotenv": {
-      "version": "4.0.3",
-      "resolved": "https://registry.npmjs.org/@types/dotenv/-/dotenv-4.0.3.tgz",
-      "integrity": "sha512-mmhpINC/HcLGQK5ikFJlLXINVvcxhlrV+ZOUJSN7/ottYl+8X4oSXzS9lBtDkmWAl96EGyGyLrNvk9zqdSH8Fw==",
+      "version": "6.1.1",
+      "resolved": "https://registry.npmjs.org/@types/dotenv/-/dotenv-6.1.1.tgz",
+      "integrity": "sha512-ftQl3DtBvqHl9L16tpqqzA4YzCSXZfi7g8cQceTz5rOlYtk/IZbFjAv3mLOQlNIgOaylCQWQoBdDQHPgEBJPHg==",
       "dev": true,
       "requires": {
-        "@types/node": "9.6.28"
+        "@types/node": "*"
       }
     },
     "@types/draft-js": {
@@ -429,9 +429,9 @@
       "dev": true
     },
     "@types/lodash": {
-      "version": "4.14.116",
-      "resolved": "https://registry.npmjs.org/@types/lodash/-/lodash-4.14.116.tgz",
-      "integrity": "sha512-lRnAtKnxMXcYYXqOiotTmJd74uawNWuPnsnPrrO7HiFuE3npE2iQhfABatbYDyxTNqZNuXzcKGhw37R7RjBFLg==",
+      "version": "4.14.123",
+      "resolved": "https://registry.npmjs.org/@types/lodash/-/lodash-4.14.123.tgz",
+      "integrity": "sha512-pQvPkc4Nltyx7G1Ww45OjVqUsJP4UsZm+GWJpigXgkikZqJgRm4c48g027o6tdgubWHwFRF15iFd+Y4Pmqv6+Q==",
       "dev": true
     },
     "@types/lz-string": {
@@ -441,9 +441,9 @@
       "dev": true
     },
     "@types/node": {
-      "version": "9.6.28",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-9.6.28.tgz",
-      "integrity": "sha512-LMSOxMKNJ8tGqUVs8lSIT8RGo1XGWYada/ZU2QZcbcD6AW9futXDE99tfQA0K6DK60GXcwplsGGK5KABRmI5GA==",
+      "version": "11.13.0",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-11.13.0.tgz",
+      "integrity": "sha512-rx29MMkRdVmzunmiA4lzBYJNnXsW/PhG4kMBy2ATsYaDjGGR75dCFEVVROKpNwlVdcUX3xxlghKQOeDPBJobng==",
       "dev": true
     },
     "@types/pixi.js": {
@@ -494,6 +494,14 @@
       "requires": {
         "@types/node": "9.6.28",
         "@types/react": "16.4.11"
+      },
+      "dependencies": {
+        "@types/node": {
+          "version": "9.6.28",
+          "resolved": "https://registry.npmjs.org/@types/node/-/node-9.6.28.tgz",
+          "integrity": "sha512-LMSOxMKNJ8tGqUVs8lSIT8RGo1XGWYada/ZU2QZcbcD6AW9futXDE99tfQA0K6DK60GXcwplsGGK5KABRmI5GA==",
+          "dev": true
+        }
       }
     },
     "@types/react-redux": {
@@ -3955,7 +3963,8 @@
     "duplexer": {
       "version": "0.1.1",
       "resolved": "https://registry.npmjs.org/duplexer/-/duplexer-0.1.1.tgz",
-      "integrity": "sha1-rOb/gIwc5mtX0ev5eXessCM0z8E="
+      "integrity": "sha1-rOb/gIwc5mtX0ev5eXessCM0z8E=",
+      "dev": true
     },
     "duplexer3": {
       "version": "0.1.4",
@@ -4358,20 +4367,6 @@
         "es5-ext": "0.10.46"
       }
     },
-    "event-stream": {
-      "version": "3.3.4",
-      "resolved": "http://registry.npmjs.org/event-stream/-/event-stream-3.3.4.tgz",
-      "integrity": "sha1-SrTJoPWlTbkzi0w02Gv86PSzVXE=",
-      "requires": {
-        "duplexer": "0.1.1",
-        "from": "0.1.7",
-        "map-stream": "0.1.0",
-        "pause-stream": "0.0.11",
-        "split": "0.3.3",
-        "stream-combiner": "0.0.4",
-        "through": "2.3.8"
-      }
-    },
     "eventemitter3": {
       "version": "2.0.3",
       "resolved": "https://registry.npmjs.org/eventemitter3/-/eventemitter3-2.0.3.tgz",
@@ -5149,11 +5144,6 @@
       "integrity": "sha1-PYyt2Q2XZWn6g1qx+OSyOhBWBac=",
       "dev": true
     },
-    "from": {
-      "version": "0.1.7",
-      "resolved": "https://registry.npmjs.org/from/-/from-0.1.7.tgz",
-      "integrity": "sha1-g8YK/Fi5xWmXAH7Rp2izqzA6RP4="
-    },
     "from2": {
       "version": "2.3.0",
       "resolved": "https://registry.npmjs.org/from2/-/from2-2.3.0.tgz",
@@ -9239,11 +9229,6 @@
       "resolved": "https://registry.npmjs.org/map-obj/-/map-obj-1.0.1.tgz",
       "integrity": "sha1-2TPOuSBdgr3PSIb2dCvcK03qFG0="
     },
-    "map-stream": {
-      "version": "0.1.0",
-      "resolved": "https://registry.npmjs.org/map-stream/-/map-stream-0.1.0.tgz",
-      "integrity": "sha1-5WqpTEyAVaFkBKBnS3jyFffI4ZQ="
-    },
     "map-visit": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/map-visit/-/map-visit-1.0.0.tgz",
@@ -12592,19 +12577,19 @@
       }
     },
     "npm-run-all": {
-      "version": "4.1.3",
-      "resolved": "https://registry.npmjs.org/npm-run-all/-/npm-run-all-4.1.3.tgz",
-      "integrity": "sha512-aOG0N3Eo/WW+q6sUIdzcV2COS8VnTZCmdji0VQIAZF3b+a3YWb0AD0vFIyjKec18A7beLGbaQ5jFTNI2bPt9Cg==",
-      "requires": {
-        "ansi-styles": "3.2.1",
-        "chalk": "2.4.1",
-        "cross-spawn": "6.0.5",
-        "memorystream": "0.3.1",
-        "minimatch": "3.0.4",
-        "ps-tree": "1.1.0",
-        "read-pkg": "3.0.0",
-        "shell-quote": "1.6.1",
-        "string.prototype.padend": "3.0.0"
+      "version": "4.1.5",
+      "resolved": "https://registry.npmjs.org/npm-run-all/-/npm-run-all-4.1.5.tgz",
+      "integrity": "sha512-Oo82gJDAVcaMdi3nuoKFavkIHBRVqQ1qvMb+9LHk/cF4P6B2m8aP04hGf7oL6wZ9BuGwX1onlLhpuoofSyoQDQ==",
+      "requires": {
+        "ansi-styles": "^3.2.1",
+        "chalk": "^2.4.1",
+        "cross-spawn": "^6.0.5",
+        "memorystream": "^0.3.1",
+        "minimatch": "^3.0.4",
+        "pidtree": "^0.3.0",
+        "read-pkg": "^3.0.0",
+        "shell-quote": "^1.6.1",
+        "string.prototype.padend": "^3.0.0"
       },
       "dependencies": {
         "ansi-styles": {
@@ -12612,17 +12597,17 @@
           "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-3.2.1.tgz",
           "integrity": "sha512-VT0ZI6kZRdTh8YyJw3SMbYm/u+NqfsAxEpWO0Pf9sq8/e94WxxOpPKx9FR1FlyCtOVDNOQ+8ntlqFxiRc+r5qA==",
           "requires": {
-            "color-convert": "1.9.2"
+            "color-convert": "^1.9.0"
           }
         },
         "chalk": {
-          "version": "2.4.1",
-          "resolved": "https://registry.npmjs.org/chalk/-/chalk-2.4.1.tgz",
-          "integrity": "sha512-ObN6h1v2fTJSmUXoS3nMQ92LbDK9be4TV+6G+omQlGJFdcUX5heKi1LZ1YnRMIgwTLEj3E24bT6tYni50rlCfQ==",
+          "version": "2.4.2",
+          "resolved": "https://registry.npmjs.org/chalk/-/chalk-2.4.2.tgz",
+          "integrity": "sha512-Mti+f9lpJNcwF4tWV8/OrTTtF1gZi+f8FqlyAdouralcFWFQWF2+NgCHShjkCb+IFBLq9buZwE1xckQU4peSuQ==",
           "requires": {
-            "ansi-styles": "3.2.1",
-            "escape-string-regexp": "1.0.5",
-            "supports-color": "5.4.0"
+            "ansi-styles": "^3.2.1",
+            "escape-string-regexp": "^1.0.5",
+            "supports-color": "^5.3.0"
           }
         },
         "cross-spawn": {
@@ -12630,11 +12615,11 @@
           "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-6.0.5.tgz",
           "integrity": "sha512-eTVLrBSt7fjbDygz805pMnstIs2VTBNkRm0qxZd+M7A5XDdxVRWO5MxGBXZhjY4cqLYLdtrGqRf8mBPmzwSpWQ==",
           "requires": {
-            "nice-try": "1.0.4",
-            "path-key": "2.0.1",
-            "semver": "5.5.1",
-            "shebang-command": "1.2.0",
-            "which": "1.3.1"
+            "nice-try": "^1.0.4",
+            "path-key": "^2.0.1",
+            "semver": "^5.5.0",
+            "shebang-command": "^1.2.0",
+            "which": "^1.2.9"
           }
         },
         "load-json-file": {
@@ -12642,10 +12627,10 @@
           "resolved": "https://registry.npmjs.org/load-json-file/-/load-json-file-4.0.0.tgz",
           "integrity": "sha1-L19Fq5HjMhYjT9U62rZo607AmTs=",
           "requires": {
-            "graceful-fs": "4.1.11",
-            "parse-json": "4.0.0",
-            "pify": "3.0.0",
-            "strip-bom": "3.0.0"
+            "graceful-fs": "^4.1.2",
+            "parse-json": "^4.0.0",
+            "pify": "^3.0.0",
+            "strip-bom": "^3.0.0"
           }
         },
         "parse-json": {
@@ -12653,8 +12638,8 @@
           "resolved": "https://registry.npmjs.org/parse-json/-/parse-json-4.0.0.tgz",
           "integrity": "sha1-vjX1Qlvh9/bHRxhPmKeIy5lHfuA=",
           "requires": {
-            "error-ex": "1.3.2",
-            "json-parse-better-errors": "1.0.2"
+            "error-ex": "^1.3.1",
+            "json-parse-better-errors": "^1.0.1"
           }
         },
         "path-type": {
@@ -12662,7 +12647,7 @@
           "resolved": "https://registry.npmjs.org/path-type/-/path-type-3.0.0.tgz",
           "integrity": "sha512-T2ZUsdZFHgA3u4e5PfPbjd7HDDpxPnQb5jN0SrDsjNSuVXHJqtwTnWqG0B1jZrgmJ/7lj1EmVIByWt1gxGkWvg==",
           "requires": {
-            "pify": "3.0.0"
+            "pify": "^3.0.0"
           }
         },
         "pify": {
@@ -12675,9 +12660,9 @@
           "resolved": "https://registry.npmjs.org/read-pkg/-/read-pkg-3.0.0.tgz",
           "integrity": "sha1-nLxoaXj+5l0WwA4rGcI3/Pbjg4k=",
           "requires": {
-            "load-json-file": "4.0.0",
-            "normalize-package-data": "2.4.0",
-            "path-type": "3.0.0"
+            "load-json-file": "^4.0.0",
+            "normalize-package-data": "^2.3.2",
+            "path-type": "^3.0.0"
           }
         },
         "strip-bom": {
@@ -12686,11 +12671,11 @@
           "integrity": "sha1-IzTBjpx1n3vdVv3vfprj1YjmjtM="
         },
         "supports-color": {
-          "version": "5.4.0",
-          "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-5.4.0.tgz",
-          "integrity": "sha512-zjaXglF5nnWpsq470jSv6P9DwPvgLkuapYmfDm3JWOm0vkNTVF2tI4UrN2r6jH1qM/uc/WtxYY1hYoA2dOKj5w==",
+          "version": "5.5.0",
+          "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-5.5.0.tgz",
+          "integrity": "sha512-QjVjwdXIt408MIiAqCX4oUKsgU2EqAGzs2Ppkm4aQYbjm+ZEWEcW4SfFNTr4uMNZma0ey4f5lgLrkB0aX0QMow==",
           "requires": {
-            "has-flag": "3.0.0"
+            "has-flag": "^3.0.0"
           }
         }
       }
@@ -13134,6 +13119,14 @@
       "dev": true,
       "requires": {
         "@types/node": "9.6.28"
+      },
+      "dependencies": {
+        "@types/node": {
+          "version": "9.6.28",
+          "resolved": "https://registry.npmjs.org/@types/node/-/node-9.6.28.tgz",
+          "integrity": "sha512-LMSOxMKNJ8tGqUVs8lSIT8RGo1XGWYada/ZU2QZcbcD6AW9futXDE99tfQA0K6DK60GXcwplsGGK5KABRmI5GA==",
+          "dev": true
+        }
       }
     },
     "parseurl": {
@@ -13213,14 +13206,6 @@
         "pinkie-promise": "2.0.1"
       }
     },
-    "pause-stream": {
-      "version": "0.0.11",
-      "resolved": "https://registry.npmjs.org/pause-stream/-/pause-stream-0.0.11.tgz",
-      "integrity": "sha1-/lo0sMvOErWqaitAPuLnO2AvFEU=",
-      "requires": {
-        "through": "2.3.8"
-      }
-    },
     "pbkdf2": {
       "version": "3.0.16",
       "resolved": "https://registry.npmjs.org/pbkdf2/-/pbkdf2-3.0.16.tgz",
@@ -13239,6 +13224,11 @@
       "resolved": "https://registry.npmjs.org/performance-now/-/performance-now-2.1.0.tgz",
       "integrity": "sha1-Ywn04OX6kT7BxpMHrjZLSzd8nns="
     },
+    "pidtree": {
+      "version": "0.3.0",
+      "resolved": "https://registry.npmjs.org/pidtree/-/pidtree-0.3.0.tgz",
+      "integrity": "sha512-9CT4NFlDcosssyg8KVFltgokyKZIFjoBxw8CTGy+5F38Y1eQWrt8tRayiUOXE+zVKQnYu5BR8JjCtvK3BcnBhg=="
+    },
     "pify": {
       "version": "2.3.0",
       "resolved": "https://registry.npmjs.org/pify/-/pify-2.3.0.tgz",
@@ -14753,14 +14743,6 @@
       "integrity": "sha1-0/wRS6BplaRexok/SEzrHXj19HY=",
       "dev": true
     },
-    "ps-tree": {
-      "version": "1.1.0",
-      "resolved": "https://registry.npmjs.org/ps-tree/-/ps-tree-1.1.0.tgz",
-      "integrity": "sha1-tCGyQUDWID8e08dplrRCewjowBQ=",
-      "requires": {
-        "event-stream": "3.3.4"
-      }
-    },
     "pseudomap": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/pseudomap/-/pseudomap-1.0.2.tgz",
@@ -16571,14 +16553,6 @@
         "wbuf": "1.7.3"
       }
     },
-    "split": {
-      "version": "0.3.3",
-      "resolved": "https://registry.npmjs.org/split/-/split-0.3.3.tgz",
-      "integrity": "sha1-zQ7qXmOiEd//frDwkcQTPi0N0o8=",
-      "requires": {
-        "through": "2.3.8"
-      }
-    },
     "split-string": {
       "version": "3.1.0",
       "resolved": "https://registry.npmjs.org/split-string/-/split-string-3.1.0.tgz",
@@ -16673,14 +16647,6 @@
         "readable-stream": "2.3.6"
       }
     },
-    "stream-combiner": {
-      "version": "0.0.4",
-      "resolved": "https://registry.npmjs.org/stream-combiner/-/stream-combiner-0.0.4.tgz",
-      "integrity": "sha1-TV5DPBhSYd3mI8o/RMWGvPXErRQ=",
-      "requires": {
-        "duplexer": "0.1.1"
-      }
-    },
     "stream-each": {
       "version": "1.2.3",
       "resolved": "https://registry.npmjs.org/stream-each/-/stream-each-1.2.3.tgz",
@@ -16757,9 +16723,9 @@
       "resolved": "https://registry.npmjs.org/string.prototype.padend/-/string.prototype.padend-3.0.0.tgz",
       "integrity": "sha1-86rvfBcZ8XDF6rHDK/eA2W4h8vA=",
       "requires": {
-        "define-properties": "1.1.3",
-        "es-abstract": "1.12.0",
-        "function-bind": "1.1.1"
+        "define-properties": "^1.1.2",
+        "es-abstract": "^1.4.3",
+        "function-bind": "^1.0.2"
       }
     },
     "string_decoder": {
@@ -16971,7 +16937,8 @@
     "through": {
       "version": "2.3.8",
       "resolved": "https://registry.npmjs.org/through/-/through-2.3.8.tgz",
-      "integrity": "sha1-DdTJ/6q8NXlgsbckEV1+Doai4fU="
+      "integrity": "sha1-DdTJ/6q8NXlgsbckEV1+Doai4fU=",
+      "dev": true
     },
     "through2": {
       "version": "2.0.3",
diff --git a/package.json b/package.json
index 61198584b6..42f50b1392 100644
--- a/package.json
+++ b/package.json
@@ -37,13 +37,13 @@
     "draft-js": "^0.10.5",
     "flexboxgrid": "^6.3.1",
     "flexboxgrid-helpers": "^1.1.3",
-    "js-slang": "0.2.0",
+    "js-slang": "0.2.1-alpha.4",
     "lodash": "^4.17.11",
     "lz-string": "^1.4.4",
     "moment": "^2.22.2",
     "node-sass-chokidar": "^1.3.4",
     "normalize.css": "^8.0.0",
-    "npm-run-all": "^4.1.3",
+    "npm-run-all": "^4.1.5",
     "pixi-filters": "^2.6.1",
     "pixi.js": "^4.8.0",
     "query-string": "^6.1.0",
@@ -74,16 +74,16 @@
     "@types/acorn": "^4.0.3",
     "@types/classnames": "^2.2.3",
     "@types/common-tags": "^1.4.0",
-    "@types/dotenv": "^4.0.3",
+    "@types/dotenv": "^6.1.1",
     "@types/draft-js": "^0.10.23",
     "@types/enzyme": "3.1.17",
     "@types/enzyme-adapter-react-16": "^1.0.2",
     "@types/estree": "^0.0.39",
     "@types/invariant": "^2.2.29",
     "@types/jest": "^22.2.3",
-    "@types/lodash": "^4.14.110",
+    "@types/lodash": "^4.14.123",
     "@types/lz-string": "^1.3.32",
-    "@types/node": "^9.6.5",
+    "@types/node": "^11.13.0",
     "@types/pixi.js": "^4.7.3",
     "@types/query-string": "^5.1.0",
     "@types/react": "^16.3.10",
diff --git a/src/mocks/context.ts b/src/mocks/context.ts
index f8047551bf..6ae96da29c 100644
--- a/src/mocks/context.ts
+++ b/src/mocks/context.ts
@@ -2,7 +2,7 @@ import { parse } from 'acorn';
 import { FunctionExpression } from 'estree';
 import Closure from 'js-slang/dist/closure';
 import createContext from 'js-slang/dist/createContext';
-import { Context, Frame } from 'js-slang/dist/types';
+import { Context, Environment } from 'js-slang/dist/types';
 import { TypeError } from 'js-slang/dist/utils/rttc';
 
 export function mockContext(chapter = 1): Context {
@@ -13,7 +13,7 @@ export function mockRuntimeContext(): Context {
   const context = createContext();
   context.runtime = {
     isRunning: true,
-    frames: [],
+    environments: [],
     nodes: [
       {
         type: 'Literal',
@@ -31,7 +31,7 @@ export function mockRuntimeContext(): Context {
 }
 
 export function mockClosure(): Closure {
-  return new Closure({} as FunctionExpression, {} as Frame, {} as Context);
+  return new Closure({} as FunctionExpression, {} as Environment, {} as Context);
 }
 
 export function mockTypeError(): TypeError {
diff --git a/src/sagas/index.ts b/src/sagas/index.ts
index 779321f5b1..d595479c89 100644
--- a/src/sagas/index.ts
+++ b/src/sagas/index.ts
@@ -257,7 +257,7 @@ function* playgroundSaga(): SagaIterator {
 
 function* evalCode(code: string, context: Context, location: WorkspaceLocation) {
   const { result, interrupted } = yield race({
-    result: call(runInContext, code, context, { scheduler: 'preemptive' }),
+    result: call(runInContext, code, context, { scheduler: 'preemptive', isNativeRunnable: true }),
     /**
      * A BEGIN_INTERRUPT_EXECUTION signals the beginning of an interruption,
      * i.e the trigger for the interpreter to interrupt execution.
diff --git a/src/utils/constants.ts b/src/utils/constants.ts
index 9696c61538..15abe06c02 100644
--- a/src/utils/constants.ts
+++ b/src/utils/constants.ts
@@ -6,8 +6,7 @@ export const IVLE_KEY = process.env.REACT_APP_IVLE_KEY;
 export const VERSION = process.env.REACT_APP_VERSION;
 export const BACKEND_URL = process.env.REACT_APP_BACKEND_URL;
 export const USE_BACKEND =
-  process.env.REACT_APP_USE_BACKEND !== '' &&
-  process.env.REACT_APP_USE_BACKEND!.toUpperCase() === 'TRUE';
+  process.env.REACT_APP_USE_BACKEND && process.env.REACT_APP_USE_BACKEND.toUpperCase() === 'TRUE';
 
 export enum LINKS {
   GITHUB_ISSUES = 'https://github.com/source-academy/cadet-frontend/issues',
diff --git a/yarn.lock b/yarn.lock
index ccdc8a3842..77c25324cd 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -221,9 +221,10 @@
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/@types/dom4/-/dom4-2.0.0.tgz#00dc42fed6b36a7a6dabb8f7a9c9e678ee644e05"
 
-"@types/dotenv@^4.0.3":
-  version "4.0.3"
-  resolved "https://registry.yarnpkg.com/@types/dotenv/-/dotenv-4.0.3.tgz#ebcfc40da7bc0728b705945b7db48485ec5b4b67"
+"@types/dotenv@^6.1.1":
+  version "6.1.1"
+  resolved "https://registry.yarnpkg.com/@types/dotenv/-/dotenv-6.1.1.tgz#f7ce1cc4fe34f0a4373ba99fefa437b0bec54b46"
+  integrity sha512-ftQl3DtBvqHl9L16tpqqzA4YzCSXZfi7g8cQceTz5rOlYtk/IZbFjAv3mLOQlNIgOaylCQWQoBdDQHPgEBJPHg==
   dependencies:
     "@types/node" "*"
 
@@ -271,17 +272,19 @@
   version "22.2.3"
   resolved "https://registry.yarnpkg.com/@types/jest/-/jest-22.2.3.tgz#0157c0316dc3722c43a7b71de3fdf3acbccef10d"
 
-"@types/lodash@^4.14.110":
-  version "4.14.110"
-  resolved "https://registry.yarnpkg.com/@types/lodash/-/lodash-4.14.110.tgz#fb07498f84152947f30ea09d89207ca07123461e"
+"@types/lodash@^4.14.123":
+  version "4.14.123"
+  resolved "https://registry.yarnpkg.com/@types/lodash/-/lodash-4.14.123.tgz#39be5d211478c8dd3bdae98ee75bb7efe4abfe4d"
+  integrity sha512-pQvPkc4Nltyx7G1Ww45OjVqUsJP4UsZm+GWJpigXgkikZqJgRm4c48g027o6tdgubWHwFRF15iFd+Y4Pmqv6+Q==
 
 "@types/lz-string@^1.3.32":
   version "1.3.32"
   resolved "https://registry.yarnpkg.com/@types/lz-string/-/lz-string-1.3.32.tgz#60e26d0f70daa6bf385b9437bb02f661a5713f81"
 
-"@types/node@*", "@types/node@^9.6.5":
-  version "9.6.5"
-  resolved "https://registry.yarnpkg.com/@types/node/-/node-9.6.5.tgz#ee700810fdf49ac1c399fc5980b7559b3e5a381d"
+"@types/node@*", "@types/node@^11.13.0":
+  version "11.13.0"
+  resolved "https://registry.yarnpkg.com/@types/node/-/node-11.13.0.tgz#b0df8d6ef9b5001b2be3a94d909ce3c29a80f9e1"
+  integrity sha512-rx29MMkRdVmzunmiA4lzBYJNnXsW/PhG4kMBy2ATsYaDjGGR75dCFEVVROKpNwlVdcUX3xxlghKQOeDPBJobng==
 
 "@types/pixi.js@^4.7.3":
   version "4.7.3"
@@ -1877,17 +1880,10 @@ chalk@1.1.3, chalk@^1.1.1, chalk@^1.1.3:
     strip-ansi "^3.0.0"
     supports-color "^2.0.0"
 
-chalk@^2.0.0, chalk@^2.0.1, chalk@^2.3.0, chalk@^2.3.2:
-  version "2.3.2"
-  resolved "https://registry.yarnpkg.com/chalk/-/chalk-2.3.2.tgz#250dc96b07491bfd601e648d66ddf5f60c7a5c65"
-  dependencies:
-    ansi-styles "^3.2.1"
-    escape-string-regexp "^1.0.5"
-    supports-color "^5.3.0"
-
-chalk@^2.1.0:
-  version "2.4.1"
-  resolved "https://registry.yarnpkg.com/chalk/-/chalk-2.4.1.tgz#18c49ab16a037b6eb0152cc83e3471338215b66e"
+chalk@^2.0.0, chalk@^2.0.1, chalk@^2.3.0, chalk@^2.3.2, chalk@^2.4.1:
+  version "2.4.2"
+  resolved "https://registry.yarnpkg.com/chalk/-/chalk-2.4.2.tgz#cd42541677a54333cf541a49108c1432b44c9424"
+  integrity sha512-Mti+f9lpJNcwF4tWV8/OrTTtF1gZi+f8FqlyAdouralcFWFQWF2+NgCHShjkCb+IFBLq9buZwE1xckQU4peSuQ==
   dependencies:
     ansi-styles "^3.2.1"
     escape-string-regexp "^1.0.5"
@@ -2415,7 +2411,7 @@ cross-spawn@^3.0.0:
     lru-cache "^4.0.1"
     which "^1.2.9"
 
-cross-spawn@^6.0.0, cross-spawn@^6.0.4:
+cross-spawn@^6.0.0, cross-spawn@^6.0.5:
   version "6.0.5"
   resolved "https://registry.yarnpkg.com/cross-spawn/-/cross-spawn-6.0.5.tgz#4a5ec7c64dfae22c3a14124dbacdee846d80cbc4"
   dependencies:
@@ -2913,7 +2909,7 @@ duplexer3@^0.1.4:
   version "0.1.4"
   resolved "https://registry.yarnpkg.com/duplexer3/-/duplexer3-0.1.4.tgz#ee01dd1cac0ed3cbc7fdbea37dc0a8f1ce002ce2"
 
-duplexer@^0.1.1, duplexer@~0.1.1:
+duplexer@^0.1.1:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/duplexer/-/duplexer-0.1.1.tgz#ace6ff808c1ce66b57d1ebf97977acb02334cfc1"
 
@@ -3196,18 +3192,6 @@ event-emitter@~0.3.5:
     d "1"
     es5-ext "~0.10.14"
 
-event-stream@~3.3.0:
-  version "3.3.4"
-  resolved "http://registry.npmjs.org/event-stream/-/event-stream-3.3.4.tgz#4ab4c9a0f5a54db9338b4c34d86bfce8f4b35571"
-  dependencies:
-    duplexer "~0.1.1"
-    from "~0"
-    map-stream "~0.1.0"
-    pause-stream "0.0.11"
-    split "0.3"
-    stream-combiner "~0.0.4"
-    through "~2.3.1"
-
 eventemitter3@1.x.x:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/eventemitter3/-/eventemitter3-1.2.0.tgz#1c86991d816ad1e504750e73874224ecf3bec508"
@@ -3671,10 +3655,6 @@ from2@^2.1.0:
     inherits "^2.0.1"
     readable-stream "^2.0.0"
 
-from@~0:
-  version "0.1.7"
-  resolved "https://registry.yarnpkg.com/from/-/from-0.1.7.tgz#83c60afc58b9c56997007ed1a768b3ab303a44fe"
-
 fs-extra@3.0.1:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-3.0.1.tgz#3794f378c58b342ea7dbbb23095109c4b3b62291"
@@ -5247,9 +5227,10 @@ js-base64@^2.1.9:
   version "2.4.3"
   resolved "https://registry.yarnpkg.com/js-base64/-/js-base64-2.4.3.tgz#2e545ec2b0f2957f41356510205214e98fad6582"
 
-js-slang@0.2.0:
-  version "0.2.0"
-  resolved "https://registry.yarnpkg.com/js-slang/-/js-slang-0.2.0.tgz#15b998d2e67bc2834421235f96408b4015bb322c"
+js-slang@0.2.1-alpha.3:
+  version "0.2.1-alpha.3"
+  resolved "https://registry.yarnpkg.com/js-slang/-/js-slang-0.2.1-alpha.3.tgz#8e93828c67e0eb729ce229f66cadc5e081730541"
+  integrity sha512-iLEhlsrW1kbZ1OZ0rlVrhrFSsAacLAjqSqLuMqO+bAbdbZq2xc1wtQk+/xrj1hnRFRJhPqZH5qQetQm8vkQqFg==
   dependencies:
     "@types/estree" "0.0.39"
     acorn "^6.0.5"
@@ -5258,6 +5239,7 @@ js-slang@0.2.0:
     commander "^2.19.0"
     common-tags "^1.8.0"
     invariant "^2.2.4"
+    source-map "^0.7.3"
 
 js-tokens@^3.0.0, js-tokens@^3.0.2:
   version "3.0.2"
@@ -5833,10 +5815,6 @@ map-obj@^1.0.0, map-obj@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/map-obj/-/map-obj-1.0.1.tgz#d933ceb9205d82bdcf4886f6742bdc2b4dea146d"
 
-map-stream@~0.1.0:
-  version "0.1.0"
-  resolved "https://registry.yarnpkg.com/map-stream/-/map-stream-0.1.0.tgz#e56aa94c4c8055a16404a0674b78f215f7c8e194"
-
 map-visit@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/map-visit/-/map-visit-1.0.0.tgz#ecdca8f13144e660f1b5bd41f12f3479d98dfb8f"
@@ -6538,16 +6516,17 @@ npm-registry-fetch@^3.0.0:
     make-fetch-happen "^4.0.0"
     npm-package-arg "^6.0.0"
 
-npm-run-all@^4.1.3:
-  version "4.1.3"
-  resolved "https://registry.yarnpkg.com/npm-run-all/-/npm-run-all-4.1.3.tgz#49f15b55a66bb4101664ce270cb18e7103f8f185"
+npm-run-all@^4.1.5:
+  version "4.1.5"
+  resolved "https://registry.yarnpkg.com/npm-run-all/-/npm-run-all-4.1.5.tgz#04476202a15ee0e2e214080861bff12a51d98fba"
+  integrity sha512-Oo82gJDAVcaMdi3nuoKFavkIHBRVqQ1qvMb+9LHk/cF4P6B2m8aP04hGf7oL6wZ9BuGwX1onlLhpuoofSyoQDQ==
   dependencies:
-    ansi-styles "^3.2.0"
-    chalk "^2.1.0"
-    cross-spawn "^6.0.4"
+    ansi-styles "^3.2.1"
+    chalk "^2.4.1"
+    cross-spawn "^6.0.5"
     memorystream "^0.3.1"
     minimatch "^3.0.4"
-    ps-tree "^1.1.0"
+    pidtree "^0.3.0"
     read-pkg "^3.0.0"
     shell-quote "^1.6.1"
     string.prototype.padend "^3.0.0"
@@ -7110,12 +7089,6 @@ path-type@^3.0.0:
   dependencies:
     pify "^3.0.0"
 
-pause-stream@0.0.11:
-  version "0.0.11"
-  resolved "https://registry.yarnpkg.com/pause-stream/-/pause-stream-0.0.11.tgz#fe5a34b0cbce12b5aa6a2b403ee2e73b602f1445"
-  dependencies:
-    through "~2.3"
-
 pbkdf2@^3.0.3:
   version "3.0.14"
   resolved "https://registry.yarnpkg.com/pbkdf2/-/pbkdf2-3.0.14.tgz#a35e13c64799b06ce15320f459c230e68e73bade"
@@ -7134,6 +7107,11 @@ performance-now@^2.1.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/performance-now/-/performance-now-2.1.0.tgz#6309f4e0e5fa913ec1c69307ae364b4b377c9e7b"
 
+pidtree@^0.3.0:
+  version "0.3.0"
+  resolved "https://registry.yarnpkg.com/pidtree/-/pidtree-0.3.0.tgz#f6fada10fccc9f99bf50e90d0b23d72c9ebc2e6b"
+  integrity sha512-9CT4NFlDcosssyg8KVFltgokyKZIFjoBxw8CTGy+5F38Y1eQWrt8tRayiUOXE+zVKQnYu5BR8JjCtvK3BcnBhg==
+
 pify@^2.0.0:
   version "2.3.0"
   resolved "https://registry.yarnpkg.com/pify/-/pify-2.3.0.tgz#ed141a6ac043a849ea588498e7dca8b15330e90c"
@@ -7641,12 +7619,6 @@ prr@~1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/prr/-/prr-1.0.1.tgz#d3fc114ba06995a45ec6893f484ceb1d78f5f476"
 
-ps-tree@^1.1.0:
-  version "1.1.0"
-  resolved "https://registry.yarnpkg.com/ps-tree/-/ps-tree-1.1.0.tgz#b421b24140d6203f1ed3c76996b4427b08e8c014"
-  dependencies:
-    event-stream "~3.3.0"
-
 pseudomap@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/pseudomap/-/pseudomap-1.0.2.tgz#f052a28da70e618917ef0a8ac34c1ae5a68286b3"
@@ -9028,6 +9000,11 @@ source-map@^0.6.0, source-map@^0.6.1, source-map@~0.6.1:
   version "0.6.1"
   resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.6.1.tgz#74722af32e9614e9c287a8d0bbde48b5e2f1a263"
 
+source-map@^0.7.3:
+  version "0.7.3"
+  resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.7.3.tgz#5302f8169031735226544092e64981f751750383"
+  integrity sha512-CkCj6giN3S+n9qrYiBTX5gystlENnRW5jZeNLHpe6aue+SrHcG5VYwujhW9s4dY31mEGsxBDrHR6oI69fTXsaQ==
+
 spdx-correct@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/spdx-correct/-/spdx-correct-3.0.0.tgz#05a5b4d7153a195bc92c3c425b69f3b2a9524c82"
@@ -9079,12 +9056,6 @@ split-string@^3.0.1, split-string@^3.0.2:
   dependencies:
     extend-shallow "^3.0.0"
 
-split@0.3:
-  version "0.3.3"
-  resolved "https://registry.yarnpkg.com/split/-/split-0.3.3.tgz#cd0eea5e63a211dfff7eb0f091c4133e2d0dd28f"
-  dependencies:
-    through "2"
-
 sprintf-js@~1.0.2:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/sprintf-js/-/sprintf-js-1.0.3.tgz#04e6926f662895354f3dd015203633b857297e2c"
@@ -9149,12 +9120,6 @@ stream-browserify@^2.0.1:
     inherits "~2.0.1"
     readable-stream "^2.0.2"
 
-stream-combiner@~0.0.4:
-  version "0.0.4"
-  resolved "https://registry.yarnpkg.com/stream-combiner/-/stream-combiner-0.0.4.tgz#4d5e433c185261dde623ca3f44c586bcf5c4ad14"
-  dependencies:
-    duplexer "~0.1.1"
-
 stream-each@^1.1.0:
   version "1.2.2"
   resolved "https://registry.yarnpkg.com/stream-each/-/stream-each-1.2.2.tgz#8e8c463f91da8991778765873fe4d960d8f616bd"
@@ -9436,7 +9401,7 @@ through2@^2.0.0:
     readable-stream "^2.1.5"
     xtend "~4.0.1"
 
-through@2, "through@>=2.2.7 <3", through@^2.3.6, through@~2.3, through@~2.3.1:
+"through@>=2.2.7 <3", through@^2.3.6:
   version "2.3.8"
   resolved "https://registry.yarnpkg.com/through/-/through-2.3.8.tgz#0dd4c9ffaabc357960b1b724115d7e0e86a2e1f5"