diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index e3014f8..f3a72c6 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -10,8 +10,8 @@ on:
     workflow_dispatch:
 
 jobs:
-    build:
-        name: Build
+    test:
+        name: Test
         runs-on: macos-latest
         env:
             GITHUB_ACTIONS_OUTPUT: ""
@@ -49,3 +49,8 @@ jobs:
               run: |
                   echo "Running in $BROWSER"
                   npm run test:${{ matrix.browser }}
+
+            - name: Run Build
+              run: |
+                  echo "Running in $BROWSER"
+                  npm run test:build
diff --git a/package.json b/package.json
index db7aca4..3cdbae5 100644
--- a/package.json
+++ b/package.json
@@ -27,7 +27,8 @@
         "test:shell": "npm run test:v8 && npm run test:jsc && npm run test:spidermonkey",
         "test:v8": "node tests/run-shell.mjs --shell v8",
         "test:jsc": "node tests/run-shell.mjs --shell jsc",
-        "test:spidermonkey": "node tests/run-shell.mjs --shell spidermonkey"
+        "test:spidermonkey": "node tests/run-shell.mjs --shell spidermonkey",
+        "test:build": "node tests/run-build.mjs"
     },
     "devDependencies": {
         "@actions/core": "^1.11.1",
diff --git a/tests/helper.mjs b/tests/helper.mjs
index 0867e8a..1dc5be2 100644
--- a/tests/helper.mjs
+++ b/tests/helper.mjs
@@ -1,6 +1,7 @@
-import { styleText } from "node:util";
 import core from "@actions/core";
+import { spawn } from "child_process";
 import commandLineUsage from "command-line-usage";
+import { styleText } from "node:util";
 
 export const GITHUB_ACTIONS_OUTPUT = "GITHUB_ACTIONS_OUTPUT" in process.env;
 
@@ -30,6 +31,16 @@ export function logError(...args) {
   }
 }
 
+export function logCommand(...args) {
+  const cmd = args.join(" ");
+  if (GITHUB_ACTIONS_OUTPUT) {
+    core.notice(styleText("blue", cmd));
+  } else {
+    console.log(styleText("blue", cmd));
+  }
+}
+
+
 export async function logGroup(name, body) {
   if (GITHUB_ACTIONS_OUTPUT) {
     core.startGroup(name);
@@ -80,3 +91,49 @@ export async function runTest(label, testFunction) {
     }
     return true;
 }
+
+
+export async function sh(binary, ...args) {
+  const cmd = `${binary} ${args.join(" ")}`;
+  if (GITHUB_ACTIONS_OUTPUT)
+    core.startGroup(binary);
+  logCommand(cmd);
+  try {
+    return await spawnCaptureStdout(binary, args);
+  } catch(e) {
+    logError(e.stdoutString);
+    throw e;
+  } finally {
+    if (GITHUB_ACTIONS_OUTPUT)
+      core.endGroup();
+  }
+}
+
+const SPAWN_OPTIONS =  Object.freeze({ 
+  stdio: ["inherit", "pipe", "inherit"]
+});
+
+async function spawnCaptureStdout(binary, args, options={}) {
+  options = Object.assign(options, SPAWN_OPTIONS);
+  const childProcess = spawn(binary, args, options);
+  childProcess.stdout.pipe(process.stdout);
+  return new Promise((resolve, reject) => {
+    childProcess.stdoutString = "";
+    childProcess.stdio[1].on("data", (data) => {
+      childProcess.stdoutString += data.toString();
+    });
+    childProcess.on("close", (code) => {
+      if (code === 0) {
+        resolve(childProcess);
+      } else {
+        // Reject the Promise with an Error on failure
+        const error = new Error(`Command failed with exit code ${code}: ${binary} ${args.join(" ")}`);
+        error.process = childProcess;
+        error.stdout = childProcess.stdoutString;
+        error.exitCode = code;
+        reject(error);
+      }
+    });
+    childProcess.on("error", reject);
+  })
+}
diff --git a/tests/run-build.mjs b/tests/run-build.mjs
new file mode 100644
index 0000000..213b0e9
--- /dev/null
+++ b/tests/run-build.mjs
@@ -0,0 +1,73 @@
+#! /usr/bin/env node
+
+import commandLineArgs from "command-line-args";
+import fs from "fs";
+import { fileURLToPath } from "url";
+import path from "path";
+
+import { logError, logCommand, printHelp, runTest, sh } from "./helper.mjs";
+
+const optionDefinitions = [
+  { name: "help", alias: "h", description: "Print this help text." },
+];
+
+const options = commandLineArgs(optionDefinitions);
+
+if ("help" in options)
+  printHelp(optionDefinitions);
+
+const FILE_PATH = fileURLToPath(import.meta.url);
+const SRC_DIR = path.dirname(path.dirname(FILE_PATH));
+
+async function findPackageJsonFiles(dir, accumulator=[]) {
+    const dirEntries = fs.readdirSync(dir, { withFileTypes: true });
+    for (const dirent of dirEntries) {
+        if (dirent.name === "node_modules" || dirent.name === ".git")
+            continue;
+        const fullPath = path.join(dir, dirent.name);
+        if (dirent.isDirectory())
+            findPackageJsonFiles(fullPath, accumulator);
+        else if (dirent.name === "package.json")
+            accumulator.push(fullPath)
+    }
+    return accumulator;
+}
+
+async function runBuilds() {
+    const packageJsonFiles = await findPackageJsonFiles(SRC_DIR);
+    let success = true;
+
+    for (const file of packageJsonFiles) {
+        const content = fs.readFileSync(file, "utf-8");
+        const packageJson = JSON.parse(content);
+        if (!packageJson.scripts?.build) {
+            continue;
+        }
+
+        const dir = path.dirname(file);
+        const relativeDir = path.relative(SRC_DIR, dir);
+        const testName = `Building ${relativeDir}`;
+        
+        const buildTask = async () => {
+            const oldCWD = process.cwd();
+            try {
+                logCommand("cd", dir);
+                process.chdir(dir);
+                await sh("npm", "ci");
+                await sh("npm", "run", "build");
+            } finally {
+                process.chdir(oldCWD);
+                // await sh("git", "reset", "--hard");
+            }
+        };
+        
+        success &&= await runTest(testName, buildTask);
+    }
+
+    if (!success) {
+        logError("One or more builds failed.");
+        process.exit(1);
+    }
+}
+
+setImmediate(runBuilds);
\ No newline at end of file
diff --git a/tests/run-shell.mjs b/tests/run-shell.mjs
index 1b626a7..b4f04c3 100644
--- a/tests/run-shell.mjs
+++ b/tests/run-shell.mjs
@@ -1,15 +1,12 @@
 #! /usr/bin/env node
 
 import commandLineArgs from "command-line-args";
-import { spawn } from  "child_process";
-import { fileURLToPath } from "url";
-import { styleText } from "node:util";
-import * as path from "path";
 import * as fs from "fs";
 import * as os from "os";
-import core from "@actions/core";
+import * as path from "path";
+import { fileURLToPath } from "url";
 
-import {logInfo, logError, logGroup, printHelp, runTest, GITHUB_ACTIONS_OUTPUT} from "./helper.mjs";
+import { logGroup, logInfo, printHelp, runTest, sh } from "./helper.mjs";
 
 const optionDefinitions = [
   { name: "shell", type: String, description: "Set the shell to test, choices are [jsc, v8, spidermonkey]." },
@@ -55,55 +52,6 @@ function convertCliArgs(cli, ...cliArgs) {
 }
 
 
-const SPAWN_OPTIONS =  { 
-  stdio: ["inherit", "inherit", "inherit"]
-};
-
-async function sh(binary, ...args) {
-  const cmd = `${binary} ${args.join(" ")}`;
-  if (GITHUB_ACTIONS_OUTPUT) {
-    core.startGroup(binary);
-    core.notice(styleText("blue", cmd));
-  } else {
-    console.log(styleText("blue", cmd));
-  }
-  try {
-    const result = await spawnCaptureStdout(binary, args, SPAWN_OPTIONS);
-    if (result.status || result.error) {
-      logError(result.error);
-      throw new Error(`Shell CMD failed: ${binary} ${args.join(" ")}`);
-    }
-    return result;
-  } finally {
-    if (GITHUB_ACTIONS_OUTPUT)
-      core.endGroup();
-  }
-}
-
-async function spawnCaptureStdout(binary, args) {
-  const childProcess = spawn(binary, args);
-  childProcess.stdout.pipe(process.stdout);
-  return new Promise((resolve, reject) => {
-    childProcess.stdoutString = "";
-    childProcess.stdio[1].on("data", (data) => {
-      childProcess.stdoutString += data.toString();
-    });
-    childProcess.on('close', (code) => {
-      if (code === 0) {
-        resolve(childProcess);
-      } else {
-        // Reject the Promise with an Error on failure
-        const error = new Error(`Command failed with exit code ${code}: ${binary} ${args.join(" ")}`);
-        error.process = childProcess;
-        error.stdout = childProcess.stdoutString;
-        error.exitCode = code;
-        reject(error);
-      }
-    });
-    childProcess.on('error', reject);
-  })
-}
-
 async function runTests() {
     const shellBinary = await logGroup(`Installing JavaScript Shell: ${SHELL_NAME}`, testSetup);
     let success = true;
diff --git a/web-ssr/package-lock.json b/web-ssr/package-lock.json
index cba3e15..561c631 100644
--- a/web-ssr/package-lock.json
+++ b/web-ssr/package-lock.json
@@ -14,6 +14,7 @@
         "@babel/node": "^7.28.0",
         "@babel/preset-env": "^7.28.0",
         "@babel/preset-react": "^7.27.1",
+        "@dapplets/unicode-escape-webpack-plugin": "^0.1.1",
         "assert": "^2.1.0",
         "babel-loader": "^10.0.0",
         "babel-node": "^0.0.1-security",
@@ -1641,6 +1642,12 @@
         "node": ">=6.9.0"
       }
     },
+    "node_modules/@dapplets/unicode-escape-webpack-plugin": {
+      "version": "0.1.1",
+      "resolved": "https://registry.npmjs.org/@dapplets/unicode-escape-webpack-plugin/-/unicode-escape-webpack-plugin-0.1.1.tgz",
+      "integrity": "sha512-dBcrCWE6ZOOHD1XLe3raXk29CwQSJQCXYx8QNcCMvfG+cZ9tZh1h2OVV7D936pmues8OTm1KhjWeiZXbH30SAg==",
+      "license": "MIT"
+    },
     "node_modules/@discoveryjs/json-ext": {
       "version": "0.6.3",
       "resolved": "https://registry.npmjs.org/@discoveryjs/json-ext/-/json-ext-0.6.3.tgz",
diff --git a/web-ssr/package.json b/web-ssr/package.json
index 973d193..1f58b47 100644
--- a/web-ssr/package.json
+++ b/web-ssr/package.json
@@ -18,6 +18,7 @@
     "@babel/node": "^7.28.0",
     "@babel/preset-env": "^7.28.0",
     "@babel/preset-react": "^7.27.1",
+    "@dapplets/unicode-escape-webpack-plugin": "^0.1.1",
     "assert": "^2.1.0",
     "babel-loader": "^10.0.0",
     "babel-node": "^0.0.1-security",