fix: reuse python worker between tests (#52617)

tools/client-plugins/browser-scripts/python-test-evaluator.ts

@@ -63,6 +63,11 @@ ctx.onmessage = async (e: PythonRunEvent) => {
 
   const assert = chai.assert;
   const __helpers = helpers;
+
+  // Create fresh globals for each test
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-call
+  const __userGlobals = pyodide.globals.get('dict')() as PyProxy;
+
   /* eslint-enable @typescript-eslint/no-unused-vars */
   // uncomment the following line to inspect
   // the frame-runner as it runs tests
@@ -109,14 +114,24 @@ ctx.onmessage = async (e: PythonRunEvent) => {
       }
     };
 
+    // Clear out the old import otherwise it will use the old input/print
+    // functions
+    pyodide.runPython(`
+import sys
+try:
+  del sys.modules['jscustom']
+  del jscustom
+except (KeyError, NameError):
+  pass
+
+`);
+
     // Make input available to python (print is not used yet)
     pyodide.registerJsModule('jscustom', {
       input: testInput
       // print: () => {}
     });
-    // Create fresh globals for each test
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-call
-    const __userGlobals = pyodide.globals.get('dict')() as PyProxy;
+
     // Some tests rely on __name__ being set to __main__ and we new dicts do not
     // have this set by default.
     // eslint-disable-next-line @typescript-eslint/no-unsafe-call
@@ -162,5 +177,7 @@ ctx.onmessage = async (e: PythonRunEvent) => {
         actual: (err as { actual?: string }).actual
       }
     });
+  } finally {
+    __userGlobals.destroy();
   }
 };

tools/client-plugins/browser-scripts/python-worker.ts

@@ -135,8 +135,8 @@ function initRunPython() {
       return ""
   `);
   // eslint-disable-next-line @typescript-eslint/no-unsafe-call
-  const getResetId = globals.get('__get_reset_id') as () => string;
-  return { runPython, getResetId };
+  const getResetId = globals.get('__get_reset_id') as PyProxy & (() => string);
+  return { runPython, getResetId, globals };
 }
 
 ctx.onmessage = (e: PythonRunEvent | ListenRequestEvent | CancelEvent) => {
@@ -165,7 +165,7 @@ function handleRunRequest(data: PythonRunEvent['data']) {
   // TODO: use reset-terminal for clarity?
   postMessage({ type: 'reset' });
 
-  const { runPython, getResetId } = initRunPython();
+  const { runPython, getResetId, globals } = initRunPython();
   // use pyodide.runPythonAsync if we want top-level await
   try {
     runPython(code);
@@ -184,5 +184,8 @@ function handleRunRequest(data: PythonRunEvent['data']) {
       // ...and tell the client that we're ignoring them.
       postMessage({ type: 'stopped', text: getResetId() });
     }
+  } finally {
+    getResetId.destroy();
+    globals.destroy();
   }
 }