diff --git a/.idea/.gitignore b/.idea/.gitignore
new file mode 100644
index 0000000..b58b603
--- /dev/null
+++ b/.idea/.gitignore
@@ -0,0 +1,5 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
diff --git a/.idea/inspectionProfiles/Project_Default.xml b/.idea/inspectionProfiles/Project_Default.xml
new file mode 100644
index 0000000..77ad396
--- /dev/null
+++ b/.idea/inspectionProfiles/Project_Default.xml
@@ -0,0 +1,6 @@
+<component name="InspectionProjectProfileManager">
+  <profile version="1.0">
+    <option name="myName" value="Project Default" />
+    <inspection_tool class="JSUnresolvedLibraryURL" enabled="false" level="WARNING" enabled_by_default="false" />
+  </profile>
+</component>
\ No newline at end of file
diff --git a/.idea/javascript-test-compat.iml b/.idea/javascript-test-compat.iml
new file mode 100644
index 0000000..0c8867d
--- /dev/null
+++ b/.idea/javascript-test-compat.iml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="WEB_MODULE" version="4">
+  <component name="NewModuleRootManager">
+    <content url="file://$MODULE_DIR$">
+      <excludeFolder url="file://$MODULE_DIR$/temp" />
+      <excludeFolder url="file://$MODULE_DIR$/.tmp" />
+      <excludeFolder url="file://$MODULE_DIR$/tmp" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>
\ No newline at end of file
diff --git a/.idea/modules.xml b/.idea/modules.xml
new file mode 100644
index 0000000..d5f83ec
--- /dev/null
+++ b/.idea/modules.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/javascript-test-compat.iml" filepath="$PROJECT_DIR$/.idea/javascript-test-compat.iml" />
+    </modules>
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/vcs.xml b/.idea/vcs.xml
new file mode 100644
index 0000000..94a25f7
--- /dev/null
+++ b/.idea/vcs.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/package.json b/package.json
index d5722be..ff196fb 100644
--- a/package.json
+++ b/package.json
@@ -16,6 +16,7 @@
   },
   "devDependencies": {
     "@types/chai": "^4.2.11",
+    "@types/node": "^18.6.4",
     "chai": "^4.2.0",
     "husky": "^4.2.5",
     "prettier": "^2.0.5",
@@ -26,5 +27,6 @@
     "hooks": {
       "pre-commit": "pretty-quick --staged"
     }
-  }
+  },
+  "dependencies": {}
 }
diff --git a/src/antiSpoilers.ts b/src/antiSpoilers.ts
new file mode 100644
index 0000000..b93def5
--- /dev/null
+++ b/src/antiSpoilers.ts
@@ -0,0 +1,64 @@
+import * as assertions from "./assertions";
+import { ExecException } from "child_process";
+
+const fs = require("fs").promises;
+const util = require("util");
+const childProcess = require("child_process");
+const performance = require("perf_hooks").performance;
+
+export const assertLag = async function assertLag(
+  callback: (...args: any) => any,
+  timeout = 4000,
+  message = "Test failed: algorithm too fast"
+) {
+  const userSolution = await fs.readFile("/home/codewarrior/solution.txt");
+  const patchedSolution = `${userSolution};
+    (${callback.toString()})();
+    `;
+  let fileIdentifier = 0;
+  let fileName;
+  while (true) {
+    try {
+      fileName = `/home/codewarrior/_lagtest${fileIdentifier}.js`;
+      await fs.writeFile(fileName, patchedSolution);
+    } catch (e) {
+      fileIdentifier++;
+      continue;
+    }
+    break;
+  }
+
+  const startTime = performance.now();
+  const lagTester = childProcess.exec(
+    `node ${fileName}`,
+    (error: ExecException | null) => {
+      if (error === null) {
+        lagTester.emit("passed");
+      } else {
+        lagTester.emit("failed");
+      }
+    }
+  );
+
+  const lagResult = await new Promise((resolve) => {
+    let interval = setInterval(() => {
+      const endTime = performance.now();
+      if (endTime - startTime >= timeout) {
+        clearInterval(interval);
+        lagTester.kill();
+      }
+    }, 200);
+
+    lagTester.on("passed", () => {
+      clearInterval(interval);
+      resolve(false);
+    });
+
+    lagTester.on("failed", () => {
+      clearInterval(interval);
+      resolve(true);
+    });
+  });
+
+  assertions.expect(lagResult, message);
+};
diff --git a/yarn.lock b/yarn.lock
index b2ab29a..8d0fe8f 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -38,6 +38,11 @@
   resolved "https://registry.yarnpkg.com/@types/minimatch/-/minimatch-3.0.3.tgz#3dca0e3f33b200fc7d1139c0cd96c1268cadfd9d"
   integrity sha512-tHq6qdbT9U1IRSGf14CL0pUlULksvY9OZ+5eEgl1N7t+OA3tGvNpxJCzuKQlsNgCVwbAs670L1vcVQi8j9HjnA==
 
+"@types/node@^18.6.4":
+  version "18.6.4"
+  resolved "https://registry.yarnpkg.com/@types/node/-/node-18.6.4.tgz#fd26723a8a3f8f46729812a7f9b4fc2d1608ed39"
+  integrity sha512-I4BD3L+6AWiUobfxZ49DlU43gtI+FTHSv9pE2Zekg6KjMpre4ByusaljW3vYSLJrvQ1ck1hUaeVu8HVlY3vzHg==
+
 "@types/parse-json@^4.0.0":
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/@types/parse-json/-/parse-json-4.0.0.tgz#2f8bb441434d163b35fb8ffdccd7138927ffb8c0"