[ty] Fix the Pyodide assets deployment in the ty playground. (#24994)

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## Summary

<!-- What's the purpose of the change? What does it do, and why? -->
- Adds some graceful degradation to Pyodide loading failures in the ty
playground (with the result that the entire playground UI doesn't
disappear if we only fail to execute a code run).
- Corrects the placement of assets in our playground deployment, and
adds some validation to the deployment workflow as a simple regression
test

Closes https://github.com/astral-sh/ty/issues/3409.

## Test Plan

I've verified the new asset layout in a local build of the playground. I
think that's sufficient, but I will monitor the production playground
deployment and revert this change if necessary.

<!-- How was it tested? -->

.github/workflows/publish-ty-playground.yml

@@ -50,6 +50,13 @@ jobs:
       - name: "Build ty playground"
         run: npm run build --workspace ty-playground
         working-directory: playground
+      - name: "Verify Pyodide assets"
+        run: |
+          test -f ty/dist/assets/pyodide.asm.js
+          test -f ty/dist/assets/pyodide.asm.wasm
+          test -f ty/dist/assets/pyodide-lock.json
+          test -f ty/dist/assets/python_stdlib.zip
+        working-directory: playground
       - name: "Deploy to Cloudflare Pages"
         if: ${{ env.CF_API_TOKEN_EXISTS == 'true' }}
         uses: cloudflare/wrangler-action@9acf94ace14e7dc412b076f2c5c20b8ce93c79cd # v3.15.0

playground/ty/src/Editor/runPython.ts

@@ -4,39 +4,40 @@ import { SerializedFiles } from "../Playground";
 const SANDBOX_BASE_DIRECTORY = "/playground/";
 
 export async function runPython(workspace: SerializedFiles): Promise<string> {
-  const pyodide = await loadPyodide({
-    env: {
-      HOME: SANDBOX_BASE_DIRECTORY,
-    },
-  });
-
   let combinedOutput = "";
 
   const outputHandler = (output: string) => {
     combinedOutput += output + "\n";
   };
 
-  pyodide.setStdout({ batched: outputHandler });
-  pyodide.setStderr({ batched: outputHandler });
+  try {
+    const pyodide = await loadPyodide({
+      env: {
+        HOME: SANDBOX_BASE_DIRECTORY,
+      },
+    });
 
-  for (const [fileName, content] of Object.entries(workspace.files)) {
-    const lastSeparator = fileName.lastIndexOf("/");
+    pyodide.setStdout({ batched: outputHandler });
+    pyodide.setStderr({ batched: outputHandler });
 
-    if (lastSeparator !== -1) {
-      const directory =
-        SANDBOX_BASE_DIRECTORY + fileName.slice(0, lastSeparator);
-      pyodide.FS.mkdirTree(directory);
+    for (const [fileName, content] of Object.entries(workspace.files)) {
+      const lastSeparator = fileName.lastIndexOf("/");
+
+      if (lastSeparator !== -1) {
+        const directory =
+          SANDBOX_BASE_DIRECTORY + fileName.slice(0, lastSeparator);
+        pyodide.FS.mkdirTree(directory);
+      }
+
+      pyodide.FS.writeFile(SANDBOX_BASE_DIRECTORY + fileName, content);
     }
 
-    pyodide.FS.writeFile(SANDBOX_BASE_DIRECTORY + fileName, content);
-  }
+    const dict = pyodide.globals.get("dict");
+    const globals = dict();
 
-  const dict = pyodide.globals.get("dict");
-  const globals = dict();
-
-  try {
     // Patch `reveal_type` to print runtime values
-    pyodide.runPython(`
+    try {
+      pyodide.runPython(`
         import builtins
 
         def reveal_type(obj):
@@ -46,17 +47,18 @@ export async function runPython(workspace: SerializedFiles): Promise<string> {
 
         builtins.reveal_type = reveal_type`);
 
-    pyodide.runPython(workspace.files[workspace.current] ?? "", {
-      globals,
-      locals: globals,
-      filename: workspace.current,
-    });
+      pyodide.runPython(workspace.files[workspace.current] ?? "", {
+        globals,
+        locals: globals,
+        filename: workspace.current,
+      });
+    } finally {
+      globals.destroy();
+      dict.destroy();
+    }
 
     return combinedOutput;
   } catch (error) {
     return `Failed to run Python script: ${error}`;
-  } finally {
-    globals.destroy();
-    dict.destroy();
   }
 }

playground/ty/vite.config.ts

@@ -28,6 +28,7 @@ export function viteStaticCopyPyodide() {
       {
         src: [pyodideDir, ...PYODIDE_EXCLUDE],
         dest: "assets",
+        rename: { stripBase: true },
       },
     ],
   });