diff --git a/.vscode/extensions.json b/.vscode/extensions.json
deleted file mode 100644
index 80e963be2..000000000
--- a/.vscode/extensions.json
+++ /dev/null
@@ -1,5 +0,0 @@
-{
-    "recommendations": [
-        "orta.vscode-jest"
-    ]
-}
\ No newline at end of file
diff --git a/.vscode/settings.json b/.vscode/settings.json
index 0235544be..63b9894cc 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -2,7 +2,4 @@
     "cmake.ignoreCMakeListsMissing": true,
     "java.compile.nullAnalysis.mode": "automatic",
     "java.configuration.updateBuildConfiguration": "automatic",
-    "jest.runMode": {
-        "type": "on-demand"
-    },
 }
diff --git a/Lara-JS/.npmrc b/Lara-JS/.npmrc
new file mode 100644
index 000000000..4fd021952
--- /dev/null
+++ b/Lara-JS/.npmrc
@@ -0,0 +1 @@
+engine-strict=true
\ No newline at end of file
diff --git a/Lara-JS/api/LaraJoinPoint.ts b/Lara-JS/api/LaraJoinPoint.ts
index e1d7efd31..595c9ea45 100644
--- a/Lara-JS/api/LaraJoinPoint.ts
+++ b/Lara-JS/api/LaraJoinPoint.ts
@@ -2,7 +2,7 @@
 // This file is generated by build-LaraJoinPoint.ts //
 //////////////////////////////////////////////////////
 
-/* eslint-disable @typescript-eslint/no-explicit-any */
+/* oxlint-disable typescript/no-explicit-any */
 
 import JavaTypes from "./lara/util/JavaTypes.ts";
 
diff --git a/Lara-JS/api/LegacyIntegrationTests - API.test.ts b/Lara-JS/api/LegacyIntegrationTests - API.test.ts
index d51fe65b9..2fe17327d 100644
--- a/Lara-JS/api/LegacyIntegrationTests - API.test.ts	
+++ b/Lara-JS/api/LegacyIntegrationTests - API.test.ts	
@@ -1,7 +1,8 @@
-import { WeaverLegacyTester } from "../jest/WeaverLegacyTester.ts";
+import { WeaverLegacyTester } from "../vitest/WeaverLegacyTester.ts";
 import path from "path";
+import PrintOnce from "./lara/util/PrintOnce.ts";
 
-/* eslint-disable jest/expect-expect */
+/* oxlint-disable vitest/expect-expect */
 describe("ApiTest", () => {
     function newTester() {
         return new WeaverLegacyTester(
@@ -29,7 +30,7 @@ describe("ApiTest", () => {
         await newTester().test("LaraCoreTest.js");
     });
 
-    it.failing("LocalFolder", async () => {
+    it.fails("LocalFolder", async () => {
         await newTester().test("LocalFolderTest.js");
     });
 
@@ -124,7 +125,12 @@ describe("ApiTest - Util", () => {
     });
 
     it("PrintOnce", async () => {
-        await newTester().test("PrintOnceTest.js");
+        {
+            await newTester().test("PrintOnceTest.js");
+        }
+
+        // Clear the PrintOnce messagesSet to avoid affecting other tests
+        PrintOnce.messagesSet.clear();
     });
 
     it("Random", async () => {
diff --git a/Lara-JS/api/LegacyIntegrationTests - JsEngine.test.ts b/Lara-JS/api/LegacyIntegrationTests - JsEngine.test.ts
index eb1c1c565..734a0387e 100644
--- a/Lara-JS/api/LegacyIntegrationTests - JsEngine.test.ts	
+++ b/Lara-JS/api/LegacyIntegrationTests - JsEngine.test.ts	
@@ -1,7 +1,7 @@
-import { WeaverLegacyTester } from "../jest/WeaverLegacyTester.ts";
+import { WeaverLegacyTester } from "../vitest/WeaverLegacyTester.ts";
 import path from "path";
 
-/* eslint-disable jest/expect-expect */
+/* oxlint-disable vitest/expect-expect */
 describe("JsEngine", () => {
     function newTester() {
         return new WeaverLegacyTester(
@@ -22,7 +22,7 @@ describe("JsEngine", () => {
         }
 
         expect(err).toBeInstanceOf(Error);
-        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        // oxlint-disable-next-line typescript/no-explicit-any
         expect((err as any).message).toContain("throwing exception in bar()");
     });
 });
diff --git a/Lara-JS/api/LegacyIntegrationTests - Weaver.test.ts b/Lara-JS/api/LegacyIntegrationTests - Weaver.test.ts
index d6810eabf..99ffe573d 100644
--- a/Lara-JS/api/LegacyIntegrationTests - Weaver.test.ts	
+++ b/Lara-JS/api/LegacyIntegrationTests - Weaver.test.ts	
@@ -1,7 +1,7 @@
-import { WeaverLegacyTester } from "../jest/WeaverLegacyTester.ts";
+import { WeaverLegacyTester } from "../vitest/WeaverLegacyTester.ts";
 import path from "path";
 
-/* eslint-disable jest/expect-expect */
+/* oxlint-disable vitest/expect-expect */
 describe("Weaver", () => {
     function newTester() {
         return new WeaverLegacyTester(
diff --git a/Lara-JS/api/jest.config.ts b/Lara-JS/api/jest.config.ts
deleted file mode 100644
index 11314baca..000000000
--- a/Lara-JS/api/jest.config.ts
+++ /dev/null
@@ -1,29 +0,0 @@
-import { defineConfig } from "jest";
-import path from "path";
-import { fileURLToPath } from "url";
-
-export const weaverConfig = {
-  weaverName: "DefaultWeaver",
-  weaverPrettyName: "Default Weaver",
-  weaverFileName: "@specs-feup/lara/code/Weaver.ts",
-  jarPath: path.join(
-    path.dirname(path.dirname(path.dirname(fileURLToPath(import.meta.url)))),
-    "./DefaultWeaver/build/install/DefaultWeaver",
-  ),
-  javaWeaverQualifiedName: "org.lara.interpreter.weaver.defaultweaver.DWWeaver",
-};
-
-export default defineConfig({
-  preset: "ts-jest/presets/default-esm",
-  testEnvironment: "@specs-feup/lara/jest/jestEnvironment.ts",
-  globalSetup: "@specs-feup/lara/jest/jestGlobalSetup.ts",
-  globalTeardown: "@specs-feup/lara/jest/jestGlobalTeardown.ts",
-  setupFiles: ["@specs-feup/lara/jest/setupFiles/sharedJavaModule.ts"],
-  setupFilesAfterEnv: ["@specs-feup/lara/jest/setupFiles/importSideEffects.ts"],
-  moduleNameMapper: {
-    "(.+)\\.js": "$1",
-  },
-  testEnvironmentOptions: {
-    weaverConfig,
-  },
-});
diff --git a/Lara-JS/api/lara/benchmark/BenchmarkInstance.ts b/Lara-JS/api/lara/benchmark/BenchmarkInstance.ts
index bdc9e6465..c175f1c00 100644
--- a/Lara-JS/api/lara/benchmark/BenchmarkInstance.ts
+++ b/Lara-JS/api/lara/benchmark/BenchmarkInstance.ts
@@ -218,14 +218,14 @@ export default abstract class BenchmarkInstance {
    */
   test(
     worker: (instance: BenchmarkInstance) => boolean = (
-      // eslint-disable-next-line @typescript-eslint/no-unused-vars
+      // oxlint-disable-next-line typescript/no-unused-vars
       _instance: BenchmarkInstance
     ) => {
       return true;
     },
     executeCode: boolean = false,
     outputProcessor: (executor: ProcessExecutor) => void = (
-      // eslint-disable-next-line @typescript-eslint/no-unused-vars
+      // oxlint-disable-next-line typescript/no-unused-vars
       _executor: ProcessExecutor
     ) => {}
   ): boolean {
diff --git a/Lara-JS/api/lara/benchmark/BenchmarkSet.ts b/Lara-JS/api/lara/benchmark/BenchmarkSet.ts
index 6c796a1b5..0f669f886 100644
--- a/Lara-JS/api/lara/benchmark/BenchmarkSet.ts
+++ b/Lara-JS/api/lara/benchmark/BenchmarkSet.ts
@@ -77,14 +77,14 @@ export default abstract class BenchmarkSet {
    */
   test(
     worker: Parameters<BenchmarkInstance["test"]>[0] = (
-      // eslint-disable-next-line @typescript-eslint/no-unused-vars
+      // oxlint-disable-next-line typescript/no-unused-vars
       _instance: BenchmarkInstance
     ) => {
       return true;
     },
     executeCode: Parameters<BenchmarkInstance["test"]>[1] = false,
     outputProcessor: Parameters<BenchmarkInstance["test"]>[2] = (
-      // eslint-disable-next-line @typescript-eslint/no-unused-vars
+      // oxlint-disable-next-line typescript/no-unused-vars
       _executor: ProcessExecutor
     ) => {}
   ): string[] {
diff --git a/Lara-JS/api/lara/metrics/FileSizeMetric.ts b/Lara-JS/api/lara/metrics/FileSizeMetric.ts
index 2034dca6c..25ee80f55 100644
--- a/Lara-JS/api/lara/metrics/FileSizeMetric.ts
+++ b/Lara-JS/api/lara/metrics/FileSizeMetric.ts
@@ -11,7 +11,7 @@ export default class FileSizeMetric extends Metric {
     super("File Size");
   }
 
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  // oxlint-disable-next-line typescript/no-unused-vars
   instrument($start: LaraJoinPoint, $end: LaraJoinPoint = $start) {}
 
   // Override
diff --git a/Lara-JS/api/lara/pass/AdapterPass.ts b/Lara-JS/api/lara/pass/AdapterPass.ts
index 789d610fc..c6333ef86 100644
--- a/Lara-JS/api/lara/pass/AdapterPass.ts
+++ b/Lara-JS/api/lara/pass/AdapterPass.ts
@@ -70,7 +70,7 @@ class AdapterPass extends SimplePass {
   }
 }
 
-// eslint-disable-next-line @typescript-eslint/no-namespace
+// oxlint-disable-next-line typescript/no-namespace
 namespace AdapterPass {
   /**
    * @param name - Name of the pass
diff --git a/Lara-JS/api/lara/pass/results/PassResult.ts b/Lara-JS/api/lara/pass/results/PassResult.ts
index 6e7fbeec6..85e21d87e 100644
--- a/Lara-JS/api/lara/pass/results/PassResult.ts
+++ b/Lara-JS/api/lara/pass/results/PassResult.ts
@@ -83,7 +83,7 @@ class PassResult {
   }
 }
 
-// eslint-disable-next-line @typescript-eslint/no-namespace
+// oxlint-disable-next-line typescript/no-namespace
 namespace PassResult {
   export interface PassResultParams {
     /**
diff --git a/Lara-JS/api/lara/util/IdGenerator.test.ts b/Lara-JS/api/lara/util/IdGenerator.test.ts
index da7e0191f..3d2f3b317 100644
--- a/Lara-JS/api/lara/util/IdGenerator.test.ts
+++ b/Lara-JS/api/lara/util/IdGenerator.test.ts
@@ -1,6 +1,10 @@
 import IdGenerator, { IdGeneratorClass } from "./IdGenerator.ts";
 
 describe("IdGenerator", () => {
+  afterEach(() => {
+    IdGenerator.idCounter.clear();
+  });
+
   describe("IdGenerator", () => {
     it("should generate ids with the correct sequence", () => {
       const id1 = IdGenerator.next("test");
diff --git a/Lara-JS/api/lara/util/JavaTypes.ts b/Lara-JS/api/lara/util/JavaTypes.ts
index a02153b43..583125390 100644
--- a/Lara-JS/api/lara/util/JavaTypes.ts
+++ b/Lara-JS/api/lara/util/JavaTypes.ts
@@ -2,7 +2,7 @@ import java from "java";
 
 export const NodeJavaPrefix = "nodeJava_";
 
-// eslint-disable-next-line @typescript-eslint/no-namespace
+// oxlint-disable-next-line typescript/no-namespace
 export namespace JavaClasses {
   export interface JavaClass {
     (...args: unknown[]): any;
@@ -10,7 +10,7 @@ export namespace JavaClasses {
     [key: string]: any;
   }
 
-  /* eslint-disable @typescript-eslint/no-empty-object-type */
+  /* oxlint-disable typescript/no-empty-object-type */
   export interface LaraI extends JavaClass {}
   export interface LaraApiTools extends JavaClass {}
   export interface LaraSystemTools extends JavaClass {
@@ -71,7 +71,7 @@ export namespace JavaClasses {
   }
   export interface ProgressCounter extends JavaClasses.JavaClass {}
   export interface LineStream extends JavaClasses.JavaClass {}
-  /* eslint-enable @typescript-eslint/no-empty-object-type */
+  /* oxlint-enable typescript/no-empty-object-type */
 }
 
 export default class JavaTypes {
diff --git a/Lara-JS/api/lara/util/PrintOnce.test.ts b/Lara-JS/api/lara/util/PrintOnce.test.ts
index 36b9a0f18..8464977c6 100644
--- a/Lara-JS/api/lara/util/PrintOnce.test.ts
+++ b/Lara-JS/api/lara/util/PrintOnce.test.ts
@@ -1,6 +1,10 @@
 import PrintOnce from "./PrintOnce.ts"
 
 describe("PrintOnce", () => {
+  afterEach(() => {
+    PrintOnce.messagesSet.clear();
+  });
+
   describe("message", () => {
     it("prints the string it receives ignoring duplicates", () => {
       const originalConsoleLog = console.log;
@@ -20,5 +24,3 @@ describe("PrintOnce", () => {
     });
   });
 });
-
-  
\ No newline at end of file
diff --git a/Lara-JS/code/ChildProcessHandling.test.ts b/Lara-JS/code/ChildProcessHandling.test.ts
index 74af93916..cc79bfbcf 100644
--- a/Lara-JS/code/ChildProcessHandling.test.ts
+++ b/Lara-JS/code/ChildProcessHandling.test.ts
@@ -1,4 +1,4 @@
-import { jest } from "@jest/globals";
+import { vi } from "vitest";
 import {
   addActiveChildProcess,
   handleExit,
@@ -36,16 +36,16 @@ describe("ChildProcessHandling", () => {
       getActiveChildProcesses()[childProcess1.pid] = childProcess1;
       getActiveChildProcesses()[childProcess2.pid] = childProcess2;
 
-      const childProcessKillSpy1 = jest
+      const childProcessKillSpy1 = vi
         .spyOn(childProcess1, "kill")
         .mockClear();
-      const childProcessOnceSpy1 = jest
+      const childProcessOnceSpy1 = vi
         .spyOn(childProcess1, "once")
         .mockClear();
-      const childProcessKillSpy2 = jest
+      const childProcessKillSpy2 = vi
         .spyOn(childProcess2, "kill")
         .mockClear();
-      const childProcessOnceSpy2 = jest
+      const childProcessOnceSpy2 = vi
         .spyOn(childProcess2, "once")
         .mockClear();
 
@@ -56,7 +56,7 @@ describe("ChildProcessHandling", () => {
       expect(childProcessKillSpy2).toHaveBeenCalledTimes(1);
       expect(childProcessOnceSpy2).toHaveBeenCalledTimes(1);
 
-      jest.restoreAllMocks();
+      vi.restoreAllMocks();
     });
   });
 });
diff --git a/Lara-JS/code/JavaError.ts b/Lara-JS/code/JavaError.ts
index 170f188a5..9d8c13db3 100644
--- a/Lara-JS/code/JavaError.ts
+++ b/Lara-JS/code/JavaError.ts
@@ -7,7 +7,7 @@ export default interface JavaError {
   };
 }
 
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
+// oxlint-disable-next-line typescript/no-explicit-any
 export function isJavaError(obj: any): obj is JavaError {
   return obj.cause != undefined;
 }
diff --git a/Lara-JS/code/Weaver.ts b/Lara-JS/code/Weaver.ts
index 4cf0beed0..cff954ac3 100644
--- a/Lara-JS/code/Weaver.ts
+++ b/Lara-JS/code/Weaver.ts
@@ -25,9 +25,9 @@ java.asyncOptions = {
 
 export class Weaver {
   private static debug: Debug.Debugger;
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  // oxlint-disable-next-line typescript/no-explicit-any
   private static datastore: any;
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  // oxlint-disable-next-line typescript/no-explicit-any
   private static javaWeaver: any;
 
   static getDatastore(): any {
@@ -77,8 +77,8 @@ export class Weaver {
     const JavaSpecsSystem = java.import("pt.up.fe.specs.util.SpecsSystem");
     JavaSpecsSystem.programStandardInit();
 
-    /* eslint-disable */
-    // This code is intentionally ignored by eslint
+    /* oxlint-disable */
+    // This code is intentionally ignored by the linter
     const JavaArrayList = java.import("java.util.ArrayList");
     const JavaFile = java.import("java.io.File");
     const JavaFileList = java.import(
@@ -155,7 +155,7 @@ export class Weaver {
     for (const file of config.importForSideEffects ?? []) {
       await import(file);
     }
-    /* eslint-enable */
+    /* oxlint-enable */
   }
 
   static start() {
diff --git a/Lara-JS/code/jest.config.ts b/Lara-JS/code/jest.config.ts
deleted file mode 100644
index 76873b4a2..000000000
--- a/Lara-JS/code/jest.config.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-import { defineConfig } from "jest";
-
-export default defineConfig({
-  preset: "ts-jest/presets/default-esm",
-  testEnvironment: "node",
-  moduleNameMapper: {
-    "(.+)\\.js": "$1",
-  },
-});
diff --git a/Lara-JS/eslint.config.ts b/Lara-JS/eslint.config.ts
deleted file mode 100644
index 7df9bdcf0..000000000
--- a/Lara-JS/eslint.config.ts
+++ /dev/null
@@ -1,52 +0,0 @@
-import js from "@eslint/js";
-import eslintConfigPrettier from "eslint-config-prettier";
-import jest from "eslint-plugin-jest";
-import tsdoc from "eslint-plugin-tsdoc";
-import { defineConfig } from "eslint/config";
-import { dirname } from "path";
-import typescriptEslint from "typescript-eslint";
-import { fileURLToPath } from "url";
-
-const __filename = fileURLToPath(import.meta.url);
-const __dirname = dirname(__filename);
-
-export default defineConfig([
-  js.configs.recommended,
-  eslintConfigPrettier,
-  ...typescriptEslint.configs.recommended,
-  {
-    plugins: {
-      "@typescript-eslint": typescriptEslint.plugin,
-      tsdoc,
-    },
-
-    languageOptions: {
-      parser: typescriptEslint.parser,
-      ecmaVersion: 5,
-      sourceType: "script",
-
-      parserOptions: {
-        project: ["./tsconfig.json", "./tsconfig.*.json"],
-        tsconfigRootDir: __dirname,
-      },
-    },
-
-    rules: {
-      "tsdoc/syntax": "warn",
-    },
-  },
-  {
-    ...jest.configs["flat/recommended"],
-    files: ["**/*.spec.ts", "**/*.test.ts"],
-
-    plugins: {
-      jest,
-    },
-
-    languageOptions: {
-      globals: {
-        ...jest.environments.globals.globals,
-      },
-    },
-  },
-]);
diff --git a/Lara-JS/jest.config.ts b/Lara-JS/jest.config.ts
deleted file mode 100644
index 3036d5e59..000000000
--- a/Lara-JS/jest.config.ts
+++ /dev/null
@@ -1,18 +0,0 @@
-import { defineConfig } from "jest";
-
-export default defineConfig({
-  preset: "ts-jest/presets/default-esm",
-  testEnvironment: "node",
-  moduleNameMapper: {
-    "(.+)\\.js": "$1",
-  },
-  notify: true,
-  notifyMode: "always",
-  //verbose: true,
-  collectCoverage: false,
-  coverageDirectory: "coverage",
-  coverageReporters: ["text", "lcov"],
-  collectCoverageFrom: ["**/*[^.d].(t|j)s"],
-  coverageProvider: "v8",
-  projects: ["api", "code"],
-});
diff --git a/Lara-JS/jest/jestEnvironment.ts b/Lara-JS/jest/jestEnvironment.ts
deleted file mode 100644
index a9cde408a..000000000
--- a/Lara-JS/jest/jestEnvironment.ts
+++ /dev/null
@@ -1,28 +0,0 @@
-import type {
-  EnvironmentContext,
-  JestEnvironmentConfig,
-} from "@jest/environment";
-import type WeaverConfiguration from "@specs-feup/lara/code/WeaverConfiguration.ts";
-import java from "java";
-import { TestEnvironment } from "jest-environment-node";
-
-export default class LaraWeaverEnvironment extends TestEnvironment {
-  private weaverConfig: WeaverConfiguration;
-
-  constructor(config: JestEnvironmentConfig, context: EnvironmentContext) {
-    super(config, context);
-    this.weaverConfig = config.projectConfig.testEnvironmentOptions
-      .weaverConfig as WeaverConfiguration;
-  }
-
-  async setup() {
-    await super.setup();
-    this.global.__SHARED_MODULE__ = java;
-    this.global.__LARA_IMPORT_FOR_SIDE_EFFECTS__ =
-      this.weaverConfig?.importForSideEffects ?? [];
-  }
-
-  async teardown() {
-    await super.teardown();
-  }
-}
diff --git a/Lara-JS/jest/jestGlobalSetup.ts b/Lara-JS/jest/jestGlobalSetup.ts
deleted file mode 100644
index d4ae593f3..000000000
--- a/Lara-JS/jest/jestGlobalSetup.ts
+++ /dev/null
@@ -1,36 +0,0 @@
-import type { Config } from "@jest/types";
-import { Weaver } from "@specs-feup/lara/code/Weaver.ts";
-import type WeaverMessageFromLauncher from "@specs-feup/lara/code/WeaverMessageFromLauncher.ts";
-import type WeaverConfiguration from "../code/WeaverConfiguration.ts";
-
-async function oneTimeSetup(
-  globalConfig: Config.GlobalConfig,
-  projectConfig: Config.ProjectConfig,
-) {
-  const weaverMessageFromLauncher: WeaverMessageFromLauncher = {
-    args: {
-      _: [],
-      $0: "",
-    },
-    config: projectConfig.testEnvironmentOptions
-      .weaverConfig as WeaverConfiguration,
-  };
-
-  await Weaver.setupWeaver(
-    weaverMessageFromLauncher.args,
-    weaverMessageFromLauncher.config,
-  );
-}
-
-let setupDone = false;
-
-export default async function (
-  globalConfig: Config.GlobalConfig,
-  projectConfig: Config.ProjectConfig,
-) {
-  if (!setupDone) {
-    await oneTimeSetup(globalConfig, projectConfig);
-    setupDone = true;
-  }
-  Weaver.start();
-}
diff --git a/Lara-JS/jest/jestGlobalTeardown.ts b/Lara-JS/jest/jestGlobalTeardown.ts
deleted file mode 100644
index 3891ecf22..000000000
--- a/Lara-JS/jest/jestGlobalTeardown.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-import { Weaver } from "@specs-feup/lara/code/Weaver.ts";
-
-export default function () {
-  Weaver.shutdown();
-}
diff --git a/Lara-JS/jest/setupFiles/importSideEffects.ts b/Lara-JS/jest/setupFiles/importSideEffects.ts
deleted file mode 100644
index 87874f1ec..000000000
--- a/Lara-JS/jest/setupFiles/importSideEffects.ts
+++ /dev/null
@@ -1,14 +0,0 @@
-// Take a look at https://github.com/specs-feup/lara-framework/issues/93 for context.
-
-// This file is executed after the test environment is set up, so we can access
-// global variables set in the test environment.
-
-declare global {
-  var __LARA_IMPORT_FOR_SIDE_EFFECTS__: string[] | undefined;
-}
-
-const importForSideEffects = globalThis.__LARA_IMPORT_FOR_SIDE_EFFECTS__ ?? [];
-
-for (const specifier of importForSideEffects) {
-  await import(specifier);
-}
diff --git a/Lara-JS/jest/setupFiles/sharedJavaModule.ts b/Lara-JS/jest/setupFiles/sharedJavaModule.ts
deleted file mode 100644
index 2c0e6f0f7..000000000
--- a/Lara-JS/jest/setupFiles/sharedJavaModule.ts
+++ /dev/null
@@ -1,7 +0,0 @@
-import { jest } from "@jest/globals";
-
-declare global {
-  var __SHARED_MODULE__: typeof import("java");
-}
-
-jest.mock("java", () => global.__SHARED_MODULE__);
diff --git a/Lara-JS/oxlint.config.ts b/Lara-JS/oxlint.config.ts
new file mode 100644
index 000000000..b2494919d
--- /dev/null
+++ b/Lara-JS/oxlint.config.ts
@@ -0,0 +1,38 @@
+import { defineConfig } from "oxlint";
+
+export default defineConfig({
+  plugins: [
+    "eslint",
+    "typescript",
+    "unicorn",
+    "oxc",
+    "import",
+    "node",
+    "vitest",
+  ],
+  jsPlugins: ["eslint-plugin-tsdoc"],
+  categories: {
+    correctness: "error",
+    perf: "warn",
+  },
+  rules: {
+    "import/no-cycle": "error",
+    "no-array-constructor": "error",
+    "no-empty": "error",
+    "no-fallthrough": "error",
+    "no-prototype-builtins": "error",
+    "no-redeclare": "error",
+    "no-regex-spaces": "error",
+    "tsdoc/syntax": "warn",
+    "typescript/ban-ts-comment": "error",
+    "typescript/no-empty-object-type": "error",
+    "typescript/no-explicit-any": "error",
+    "typescript/no-namespace": "error",
+    "typescript/no-require-imports": "error",
+    "typescript/no-unnecessary-type-constraint": "error",
+    "typescript/no-unsafe-function-type": "error",
+  },
+  options: {
+    typeAware: true,
+  },
+});
diff --git a/Lara-JS/package.json b/Lara-JS/package.json
index 29c947848..505bf2767 100644
--- a/Lara-JS/package.json
+++ b/Lara-JS/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@specs-feup/lara",
-  "version": "3.5.1",
+  "version": "4.0.0",
   "description": "A js port of the popular framework for building source-to-source compilers",
   "type": "module",
   "bin": {
@@ -17,37 +17,24 @@
     "./code/*.js": "./code/*.ts",
     "./code/*": "./code/*.ts",
     "./code/*.ts": "./code/*.ts",
-    "./jest/*.test.ts": null,
-    "./jest/*.config.ts": null,
-    "./jest/*.js": "./jest/*.ts",
-    "./jest/*": "./jest/*.ts",
-    "./jest/*.ts": "./jest/*.ts",
-    "./eslint.config.ts": "./eslint.config.ts",
-    "./jest.config.ts": "./jest.config.ts",
+    "./vitest/*.test.ts": null,
+    "./vitest/*.config.ts": null,
+    "./vitest/*.js": "./vitest/*.ts",
+    "./vitest/*": "./vitest/*.ts",
+    "./vitest/*.ts": "./vitest/*.ts",
+    "./scripts/validateJavaBinaries.js": "./scripts/validateJavaBinaries.ts",
+    "./oxlint.config.ts": "./oxlint.config.ts",
+    "./vitest.config.ts": "./vitest.config.ts",
     "./LaraJoinPointSpecification.json": "./LaraJoinPointSpecification.json",
     "./typedoc.base.json": "./typedoc.base.json"
   },
-  "files": [
-    "api",
-    "code",
-    "jest",
-    "scripts",
-    ".gitignore",
-    "eslint.config.ts",
-    "jest.config.ts",
-    "LaraJoinPointSpecification.json",
-    "LICENSE",
-    "package.json",
-    "README.md",
-    "tsconfig.json",
-    "typedoc.base.json",
-    "typedoc.config.js"
-  ],
   "scripts": {
     "build": "tsc",
     "build:watch": "npm run build -- --watch",
-    "lint": "eslint --flag unstable_native_nodejs_ts_config .",
-    "test": "cross-env NODE_OPTIONS=\"$NODE_OPTIONS --experimental-vm-modules\" jest --detectOpenHandles --forceExit",
+    "lint": "oxlint .",
+    "format": "oxfmt .",
+    "format:check": "oxfmt --check .",
+    "test": "vitest run",
     "test:api": "npm run test -- api",
     "test:code": "npm run test -- code",
     "test:cov": "npm run test -- --coverage",
@@ -73,7 +60,8 @@
   },
   "homepage": "https://github.com/specs-feup/lara-framework#readme",
   "engines": {
-    "node": ">=24.0.0"
+    "node": ">=24.0.0",
+    "npm": ">=7"
   },
   "dependencies": {
     "chokidar": "^5.0.0",
@@ -84,21 +72,19 @@
     "supports-color": "^10.2.2",
     "yargs": "^18.0.0"
   },
+  "peerDependencies": {
+    "@vitest/coverage-v8": "^4.1.10",
+    "eslint-plugin-tsdoc": "^0.5.0",
+    "oxfmt": "^0.59.0",
+    "oxlint": "^1.74.0",
+    "oxlint-tsgolint": "^7.0.2001",
+    "vitest": "^4.1.10"
+  },
   "devDependencies": {
-    "@jest/globals": "^30.2.0",
     "@types/debug": "^4.1.12",
-    "@types/jest": "^30.0.0",
-    "@types/node": "^25.0.0",
+    "@types/node": "^24.0.0",
     "@types/yargs": "^17.0.35",
-    "cross-env": "^10.1.0",
-    "eslint": "^9.39.2",
-    "eslint-config-prettier": "^10.1.8",
-    "eslint-plugin-jest": "^29.12.1",
-    "eslint-plugin-tsdoc": "^0.5.0",
-    "jest": "^30.2.0",
     "node-notifier": "^10.0.1",
-    "ts-jest": "^29.4.6",
-    "typescript": "^6.0.3",
-    "typescript-eslint": "^8.52.0"
+    "typescript": "^7.0.2"
   }
 }
diff --git a/Lara-JS/scripts/build-LaraJoinPoint.ts b/Lara-JS/scripts/build-LaraJoinPoint.ts
index 4610deb20..96d9511dc 100644
--- a/Lara-JS/scripts/build-LaraJoinPoint.ts
+++ b/Lara-JS/scripts/build-LaraJoinPoint.ts
@@ -25,7 +25,7 @@ function buildLaraJoinPoint(inputFileName: string, outputFileName: string) {
 // This file is generated by build-LaraJoinPoint.ts //
 //////////////////////////////////////////////////////
 
-/* eslint-disable @typescript-eslint/no-explicit-any */
+/* oxlint-disable typescript/no-explicit-any */
 
 import JavaTypes from "./lara/util/JavaTypes.ts";
 
diff --git a/Lara-JS/scripts/validateJavaBinaries.ts b/Lara-JS/scripts/validateJavaBinaries.ts
new file mode 100644
index 000000000..f92014f73
--- /dev/null
+++ b/Lara-JS/scripts/validateJavaBinaries.ts
@@ -0,0 +1,41 @@
+import fs from "node:fs";
+import path from "node:path";
+
+const remediation =
+  "Run this weaver's Gradle build or installDist task before packaging.";
+
+export function validateJavaBinaries(): void {
+  const javaBinariesPath = path.resolve("java-binaries");
+
+  if (!fs.existsSync(javaBinariesPath)) {
+    fail(`Java distribution is missing at '${javaBinariesPath}'.`);
+  }
+
+  const javaBinariesStats = fs.lstatSync(javaBinariesPath);
+  if (javaBinariesStats.isSymbolicLink()) {
+    fail(
+      `Java distribution at '${javaBinariesPath}' is a symbolic link, whose contents npm will not package.`,
+    );
+  }
+
+  if (!javaBinariesStats.isDirectory()) {
+    fail(`Java distribution at '${javaBinariesPath}' is not a directory.`);
+  }
+
+  const libPath = path.join(javaBinariesPath, "lib");
+  if (!fs.existsSync(libPath) || !fs.lstatSync(libPath).isDirectory()) {
+    fail(`Java library directory is missing at '${libPath}'.`);
+  }
+
+  const hasJar = fs
+    .readdirSync(libPath, { withFileTypes: true })
+    .some((entry) => entry.isFile() && entry.name.endsWith(".jar"));
+
+  if (!hasJar) {
+    fail(`Java library directory at '${libPath}' contains no JAR files.`);
+  }
+}
+
+function fail(message: string): never {
+  throw new Error(`${message} ${remediation}`);
+}
diff --git a/Lara-JS/tsconfig.json b/Lara-JS/tsconfig.json
index 45c211456..416c10933 100644
--- a/Lara-JS/tsconfig.json
+++ b/Lara-JS/tsconfig.json
@@ -6,7 +6,7 @@
     "strict": true,
     "isolatedModules": true,
     "allowSyntheticDefaultImports": true,
-    "types": ["node", "jest"],
+    "types": ["node", "vitest/globals"],
     "rewriteRelativeImportExtensions": true,
     "erasableSyntaxOnly": true,
     "verbatimModuleSyntax": true
diff --git a/Lara-JS/vitest.config.ts b/Lara-JS/vitest.config.ts
new file mode 100644
index 000000000..d0e213922
--- /dev/null
+++ b/Lara-JS/vitest.config.ts
@@ -0,0 +1,15 @@
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { createWeaverVitestConfig } from "./vitest/weaverVitestConfig.ts";
+
+export default createWeaverVitestConfig({
+  jarPath: path.join(
+    path.dirname(path.dirname(fileURLToPath(import.meta.url))),
+    "./DefaultWeaver/build/install/DefaultWeaver",
+  ),
+  javaWeaverQualifiedName:
+    "org.lara.interpreter.weaver.defaultweaver.DWWeaver",
+  weaverFileName: "@specs-feup/lara/code/Weaver.ts",
+  weaverName: "DefaultWeaver",
+  weaverPrettyName: "Default Weaver",
+});
diff --git a/Lara-JS/jest/WeaverLegacyTester.ts b/Lara-JS/vitest/WeaverLegacyTester.ts
similarity index 90%
rename from Lara-JS/jest/WeaverLegacyTester.ts
rename to Lara-JS/vitest/WeaverLegacyTester.ts
index c428a1468..94c77746c 100644
--- a/Lara-JS/jest/WeaverLegacyTester.ts
+++ b/Lara-JS/vitest/WeaverLegacyTester.ts
@@ -1,19 +1,22 @@
-import { jest } from "@jest/globals";
+import { vi } from "vitest";
 import JavaTypes, {
   type JavaClasses,
 } from "@specs-feup/lara/api/lara/util/JavaTypes.ts";
 import Weaver from "@specs-feup/lara/api/weaver/Weaver.ts";
 import fs from "fs";
 import path from "path";
+import { pathToFileURL } from "url";
 import util from "util";
 
+let legacyScriptRun = 0;
+
 afterAll(() => {
   const javaWeaver = Weaver.getWeaverEngine();
   const javaDatastore = javaWeaver.getData().get();
 
   javaDatastore.set(
     JavaTypes.LaraiKeys.WORKSPACE_FOLDER,
-    JavaTypes.FileList.newInstance()
+    JavaTypes.FileList.newInstance(),
   );
 
   javaWeaver.run(javaDatastore);
@@ -128,7 +131,7 @@ export class WeaverLegacyTester {
     }
 
     let out = "";
-    const log = jest.spyOn(global.console, "log");
+    const log = vi.spyOn(global.console, "log");
     log.mockImplementation((data, ...args: unknown[]) => {
       if (data) {
         out += util.format(data, ...args);
@@ -142,11 +145,11 @@ export class WeaverLegacyTester {
 
       for (const codeResource of codeResources) {
         const javaFile = new JavaTypes.File(
-          this.buildCodeResource(codeResource)
+          this.buildCodeResource(codeResource),
         );
         if (!fs.existsSync(javaFile.getAbsolutePath())) {
           throw new Error(
-            `Code resource '${codeResource}' does not exist at '${javaFile.getAbsolutePath()}'.`
+            `Code resource '${codeResource}' does not exist at '${javaFile.getAbsolutePath()}'.`,
           );
         }
         javaFiles.add(javaFile);
@@ -157,11 +160,15 @@ export class WeaverLegacyTester {
 
       javaDatastore.set(
         JavaTypes.LaraiKeys.WORKSPACE_FOLDER,
-        JavaTypes.FileList.newInstance(javaFiles)
+        JavaTypes.FileList.newInstance(javaFiles),
       );
 
       javaWeaver.run(javaDatastore);
-      await import(path.join(this.basePackage, laraResource));
+      const scriptUrl = pathToFileURL(
+        path.join(this.basePackage, laraResource),
+      );
+      scriptUrl.searchParams.set("vitestRun", String(legacyScriptRun++));
+      await import(scriptUrl.href);
       javaWeaver.end();
     } finally {
       log.mockRestore();
@@ -192,7 +199,7 @@ export class WeaverLegacyTester {
         "Could not find resource '" +
           expectedResource +
           "'. Actual output:\n" +
-          out
+          out,
       );
 
       throw new Error("Expected outputs not found");
@@ -202,8 +209,8 @@ export class WeaverLegacyTester {
       WeaverLegacyTester.normalize(
         fs
           .readFileSync(expectedResource, "utf8")
-          .replaceAll(`/**** File '${this.WORK_FOLDER}/`, "/**** File '")
-      )
+          .replaceAll(`/**** File '${this.WORK_FOLDER}/`, "/**** File '"),
+      ),
     );
   }
 
diff --git a/Lara-JS/vitest/validateJavaBinaries.test.ts b/Lara-JS/vitest/validateJavaBinaries.test.ts
new file mode 100644
index 000000000..49997e571
--- /dev/null
+++ b/Lara-JS/vitest/validateJavaBinaries.test.ts
@@ -0,0 +1,66 @@
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import { validateJavaBinaries } from "../scripts/validateJavaBinaries.ts";
+
+const originalWorkingDirectory = process.cwd();
+let packageRoot: string;
+
+beforeEach(() => {
+  packageRoot = fs.mkdtempSync(path.join(os.tmpdir(), "lara-java-binaries-"));
+  process.chdir(packageRoot);
+});
+
+afterEach(() => {
+  process.chdir(originalWorkingDirectory);
+  fs.rmSync(packageRoot, { force: true, recursive: true });
+});
+
+describe("validateJavaBinaries", () => {
+  it("rejects a missing Java distribution", () => {
+    expect(() => validateJavaBinaries()).toThrow("Java distribution is missing");
+  });
+
+  it("rejects a symbolic link", () => {
+    const target = path.join(packageRoot, "distribution");
+    fs.mkdirSync(target);
+    fs.symlinkSync(
+      target,
+      path.join(packageRoot, "java-binaries"),
+      process.platform === "win32" ? "junction" : "dir",
+    );
+
+    expect(() => validateJavaBinaries()).toThrow("is a symbolic link");
+  });
+
+  it("rejects a non-directory distribution", () => {
+    fs.writeFileSync(path.join(packageRoot, "java-binaries"), "not a directory");
+
+    expect(() => validateJavaBinaries()).toThrow("is not a directory");
+  });
+
+  it("rejects a missing Java library directory", () => {
+    fs.mkdirSync(path.join(packageRoot, "java-binaries"));
+
+    expect(() => validateJavaBinaries()).toThrow(
+      "Java library directory is missing",
+    );
+  });
+
+  it("rejects a Java library directory without JAR files", () => {
+    const libPath = path.join(packageRoot, "java-binaries", "lib");
+    fs.mkdirSync(libPath, { recursive: true });
+    fs.writeFileSync(path.join(libPath, "README.txt"), "not a JAR");
+
+    expect(() => validateJavaBinaries()).toThrow("contains no JAR files");
+  });
+
+  it("accepts a materialized Java distribution containing JAR files", () => {
+    const libPath = path.join(packageRoot, "java-binaries", "lib");
+    fs.mkdirSync(libPath, { recursive: true });
+    fs.writeFileSync(path.join(libPath, "README.txt"), "metadata");
+    fs.writeFileSync(path.join(libPath, "weaver.jar"), "JAR contents");
+
+    expect(() => validateJavaBinaries()).not.toThrow();
+  });
+});
diff --git a/Lara-JS/vitest/weaverEnvironment.ts b/Lara-JS/vitest/weaverEnvironment.ts
new file mode 100644
index 000000000..2c2cdd285
--- /dev/null
+++ b/Lara-JS/vitest/weaverEnvironment.ts
@@ -0,0 +1,53 @@
+import java from "java";
+import type { Environment } from "vitest/environments";
+import { Weaver } from "../code/Weaver.ts";
+import type WeaverConfiguration from "../code/WeaverConfiguration.ts";
+
+export interface WeaverEnvironmentOptions extends Record<string, unknown> {
+  weaver: WeaverConfiguration;
+}
+
+const exitProcess = process.exit.bind(process);
+
+const environment: Environment = {
+  name: "weaver",
+  viteEnvironment: "ssr",
+
+  async setup(global, rawOptions) {
+    const options = rawOptions as unknown as WeaverEnvironmentOptions;
+    let weaverStarted = false;
+
+    // Vitest sends all results (including worker coverage) before it terminates
+    // the fork. Stopping node-java any earlier also closes Vitest's IPC handle.
+    process.once("SIGTERM", () => {
+      let exitCode = 0;
+
+      try {
+        if (weaverStarted) {
+          Weaver.shutdown();
+        }
+        java.stop();
+      } catch (error) {
+        console.error("Failed to stop the Weaver Java runtime cleanly.", error);
+        exitCode = 1;
+      } finally {
+        exitProcess(exitCode);
+      }
+    });
+
+    const message = {
+      args: { _: [], $0: "" },
+      config: options.weaver,
+    };
+
+    await Weaver.setupWeaver(message.args, message.config);
+    Weaver.start();
+    weaverStarted = true;
+
+    return {
+      teardown() {},
+    };
+  },
+};
+
+export default environment;
diff --git a/Lara-JS/jest/jestHelpers.ts b/Lara-JS/vitest/weaverTestHelpers.ts
similarity index 96%
rename from Lara-JS/jest/jestHelpers.ts
rename to Lara-JS/vitest/weaverTestHelpers.ts
index 503af5e0e..e44d1af63 100644
--- a/Lara-JS/jest/jestHelpers.ts
+++ b/Lara-JS/vitest/weaverTestHelpers.ts
@@ -33,7 +33,7 @@ export function registerSourceCodes(codes: Record<string, string>): void {
 
     javaDatastore.set(
       JavaTypes.LaraiKeys.WORKSPACE_FOLDER,
-      JavaTypes.FileList.newInstance()
+      JavaTypes.FileList.newInstance(),
     );
 
     javaWeaver.run(javaDatastore);
diff --git a/Lara-JS/vitest/weaverVitestConfig.ts b/Lara-JS/vitest/weaverVitestConfig.ts
new file mode 100644
index 000000000..ebd1e51e1
--- /dev/null
+++ b/Lara-JS/vitest/weaverVitestConfig.ts
@@ -0,0 +1,36 @@
+import { fileURLToPath } from "node:url";
+import type WeaverConfiguration from "../code/WeaverConfiguration.ts";
+import { defineConfig } from "vitest/config";
+
+function getEnvironmentPath(url: URL): string {
+  const path = fileURLToPath(url).replaceAll("\\", "/");
+
+  // Vitest only treats environment names starting with "." or "/" as file
+  // paths; a Windows drive path ("C:/...") parses as a URL scheme. The
+  // leading "/" makes Vitest's pathe-based resolve recover the drive root.
+  return process.platform === "win32" ? `/${path}` : path;
+}
+
+export function createWeaverVitestConfig(weaver: WeaverConfiguration) {
+  return defineConfig({
+    test: {
+      coverage: {
+        include: ["**/*.{t,j}s"],
+        provider: "v8",
+        reporter: ["text", "lcov"],
+      },
+      environment: getEnvironmentPath(
+        new URL("./weaverEnvironment.ts", import.meta.url),
+      ),
+      environmentOptions: { weaver },
+      experimental: {
+        viteModuleRunner: false,
+      },
+      fileParallelism: false,
+      globals: true,
+      isolate: false,
+      maxWorkers: 1,
+      pool: "forks",
+    },
+  });
+}