diff --git a/backend/api.js b/backend/api.js
index cb4c806..5b9b621 100644
--- a/backend/api.js
+++ b/backend/api.js
@@ -234,6 +234,8 @@ export class Session {
             this.logBadMessage(msg);
             break;
           }
+          await this.runCode(msg.code)
+          await this.runCode(msg.code, true, msg.expectedOutput);
           await this.runCode(msg.code, true, msg.expectedOutput);
           break;
         case "formatCode":
@@ -286,11 +288,7 @@ export class Session {
     await this.run(this.privilegedExec(`cat > ${file}`), { input: code });
   };
 
-  runCode = async (code, isTest = false, expectedOutput) => {
-    console.log('runCode')
-    console.log('code', code)
-    console.log('isTest', isTest)
-    console.log('expectedOutput', expectedOutput)
+  runCode = async (code, isTest = false, expectedOutput, testData = []) => {
     try {
       const { name, repl, suffix, createEmpty, compile, run, template } =
         this.config;
@@ -329,22 +327,22 @@ export class Session {
         live: true,
       };
       this.term = term;
+
+      this.term.pty.stdout.on("end", () => {
+        this.send({
+          event: "stdout end",
+          expectedOutput,
+          isTest,
+        });
+      });
       this.term.pty.stdout.on("data", (data) => {
         // Capture term in closure so that we don't keep sending output
         // from the old pty even after it's been killed (see ghci).
         if (term.live) {
-          if (isTest) {
-            this.send({
-              event: "testTerminalOutput",
-              output: data.toString(),
-              expectedOutput
-            });
-          } else {
-            this.send({
-              event: "terminalOutput",
-              output: data.toString()
-            });
-          }
+          this.send({
+            event: "terminalOutput",
+            output: data.toString(),
+          });
         }
       });
       this.term.pty.stderr.on("data", (data) => {
diff --git a/backend/test-runner.js b/backend/test-runner.js
index 3ca350f..2e63b9b 100644
--- a/backend/test-runner.js
+++ b/backend/test-runner.js
@@ -573,8 +573,8 @@ async function getImageHash(tag) {
   const output = (
     await run(["docker", "inspect", `riju:${tag}`], console.error, {
       suppressOutput: true,
-    })
-  ).output;
+    }).output
+  );
   return JSON.parse(output)[0].Config.Labels["riju.image-hash"];
 }
 
diff --git a/backend/util.js b/backend/util.js
index 4e5d7b4..6e672e8 100644
--- a/backend/util.js
+++ b/backend/util.js
@@ -63,10 +63,13 @@ export async function run(args, log, options) {
   if (typeof input === "string") {
     proc.stdin.end(input);
   }
-  let output = "";
+  let output = "start\n";
   proc.stdout.on("data", (data) => {
     output += `${data}`;
   });
+  proc.stdout.on("end", () => {
+    output += "\nend"
+  })
   proc.stderr.on("data", (data) => {
     output += `${data}`;
   });
@@ -74,6 +77,7 @@ export async function run(args, log, options) {
     proc.on("error", reject);
     proc.on("close", (code, signal) => {
       output = output.trim();
+      console.log(output)
       if (output && !suppressOutput) {
         log(`Output from ${args[0]}:\n` + output);
       }
diff --git a/frontend/src/app.js b/frontend/src/app.js
index 9e4c4b4..1115bb2 100644
--- a/frontend/src/app.js
+++ b/frontend/src/app.js
@@ -66,7 +66,6 @@ async function main() {
     } catch (e) {
       console.log("message error: ", e);
     }
-    console.log("message from codeamigo", msg);
   });
 
   function tryConnect() {
@@ -83,6 +82,7 @@ async function main() {
     socket.addEventListener("open", () => {
       console.log("Successfully connected to server");
     });
+    let testData = [];
     socket.addEventListener("message", (event) => {
       let message;
       try {
@@ -112,7 +112,15 @@ async function main() {
             return;
           }
           term.write(message.output);
+          testData.push(message.output);
           return;
+        case "stdout end":
+          console.log(testData);
+          console.log(msg.isTest);
+          console.log(msg.expectedOutput);
+          console.log(testData);
+          testData = [];
+          return
         case "testTerminalOutput":
           if (typeof message.output !== "string") {
             console.error("Unexpected message from server:", message);
@@ -120,32 +128,46 @@ async function main() {
           }
           term.write(message.output);
 
-          const pass = message.output.replace(/\r\n/g, '') == message.expectedOutput
-          
-          window.parent.postMessage({
-            event: "total_test_start",
-            type: "test",
-          }, "*");
+          const pass =
+            message.output.replace(/\r\n/g, "") == message.expectedOutput;
 
-          window.parent.postMessage({
-            $id: 0,
-            codesandbox: true,
-            event: "test_end",
-            test: {
-              blocks: ["Output"],
-              duration: 1,
-              errors: [],
-              name: `should be ${message.expectedOutput}.`,
-              path: "",
-              status: pass ? "pass" : "fail",
+          window.parent.postMessage(
+            {
+              event: "total_test_start",
+              type: "test",
             },
-            type: "test",
-          }, "*");
+            "*"
+          );
 
-          window.parent.postMessage({
-            event: "total_test_end",
-            type: "test",
-          }, "*");
+          window.parent.postMessage(
+            {
+              $id: 0,
+              codesandbox: true,
+              event: "test_end",
+              test: {
+                blocks: ["Output"],
+                duration: 1,
+                errors: [
+                  `${message.output.replace(/\r\n/g, "")} did not equal ${
+                    message.expectedOutput
+                  }`,
+                ],
+                name: `should be ${message.expectedOutput}.`,
+                path: "",
+                status: pass ? "pass" : "fail",
+              },
+              type: "test",
+            },
+            "*"
+          );
+
+          window.parent.postMessage(
+            {
+              event: "total_test_end",
+              type: "test",
+            },
+            "*"
+          );
           return;
         case "lspStopped":
           if (clientDisposable) {
diff --git a/langs/javascript.yaml b/langs/javascript.yaml
new file mode 100644
index 0000000..adb7bcc
--- /dev/null
+++ b/langs/javascript.yaml
@@ -0,0 +1,48 @@
+id: "javascript"
+aliases:
+  - "node"
+  - "js"
+  - "web"
+  - "jsx"
+  - "v8"
+  - "closure"
+  - "nodejs"
+name: "JavaScript"
+monacoLang: javascript
+
+install:
+  apt:
+    - nodejs
+    - yarn
+  riju:
+    - prettier
+
+repl: |
+  node
+
+main: "main.js"
+template: |
+  console.log("Hello, world!");
+
+run: |
+  node -e "$(< main.js)" -i
+
+scope:
+  code: |
+    let x = 123 * 234;
+
+format:
+  run: |
+    prettier --no-config --stdin-filepath=format.js
+  input: |
+    console.log('Hello, world!');
+
+pkg:
+  install: |
+    yarn add NAME
+
+  uninstall: |
+    yarn remove NAME
+
+  search: |
+    curl -sS 'https://registry.npmjs.org/-/v1/search?text=NAME' | jq -r '.objects | map(.package.name) | .[]'
\ No newline at end of file