Create a unit test that launches the worker and run the app

packages/kernel/src/worker-runtime.test.ts

@@ -0,0 +1,70 @@
+import path from "node:path";
+import { test } from "vitest";
+import { startWorkerEnv, PostMessageFn } from "./worker-runtime";
+import stliteServerWheelUrl from "stlite_server.whl"; // This is the alias from vitest.config.ts
+import streamlitWheelUrl from "streamlit.whl"; // This is the alias from vitest.config.ts
+
+const pyodideUrl = path.resolve("../../node_modules/pyodide/pyodide.mjs"); // Installed at the Yarn workspace root;
+
+function getWheelInstallPath(wheelImportUrl: string): string {
+  // `wheelImportUrl` is like `/path/to/stlite_server.whl` that is a URL path.
+  // We need to convert it to a local file path so that it can be referred to in the test environment i.e. Node.js.
+  // Also, we need to add `file://` scheme to it so that `micropip.install()` can install it.
+  return "file://" + path.resolve("." + wheelImportUrl);
+}
+
+test(
+  "E2E test running an app",
+  async () => {
+    console.log({
+      stliteServerWheelUrl,
+      streamlitWheelUrl,
+    });
+    const loadedPromise = new Promise<void>((resolve, reject) => {
+      const postMessage: PostMessageFn = (message) => {
+        if (message.type === "event:loaded") {
+          resolve();
+        } else if (message.type === "event:error") {
+          reject(message.data.error);
+        }
+      };
+      const onMessage = startWorkerEnv(pyodideUrl, postMessage);
+      onMessage(
+        new MessageEvent("message", {
+          data: {
+            type: "initData",
+            data: {
+              files: {
+                "app.py": {
+                  data: `
+import streamlit as st
+
+st.title("Hello World")
+`,
+                },
+              },
+              entrypoint: "app.py",
+              wheels: {
+                stliteServer: getWheelInstallPath(
+                  stliteServerWheelUrl as unknown as string,
+                ),
+                streamlit: getWheelInstallPath(
+                  streamlitWheelUrl as unknown as string,
+                ),
+              },
+              archives: [],
+              requirements: [],
+              moduleAutoLoad: false,
+              prebuiltPackageNames: [],
+            },
+          },
+        }),
+      );
+    });
+
+    await loadedPromise;
+  },
+  {
+    timeout: 60000,
+  },
+);

packages/kernel/vitest.config.ts

@@ -1,10 +1,24 @@
 /// <reference types="vitest" />
 
 import { defineConfig } from "vite";
+import path from "node:path";
 
 export default defineConfig({
   test: {
     environment: "jsdom", // We use jsdom because happy-dom does not work well with iframe.
     setupFiles: ["./setupTests.ts"],
   },
+  resolve: {
+    alias: {
+      "stlite_server.whl": path.resolve(
+        __dirname,
+        "./py/stlite-server/dist/stlite_server-0.1.0-py3-none-any.whl",
+      ),
+      "streamlit.whl": path.resolve(
+        __dirname,
+        "./py/streamlit/lib/dist/streamlit-1.35.0-cp312-none-any.whl",
+      ),
+    },
+  },
+  assetsInclude: ["**/*.whl"],
 });