Ensure `Console` is locked and prevent `formatted_traceback` being unexpectedly truncated (#4905)

Co-authored-by: Gyeongjae Choi <def6488@gmail.com>

docs/project/changelog.md

@@ -50,6 +50,13 @@ myst:
   in `CodeRunner` and `Console`.
   {pr}`4897`
 
+- {{ Fix }} Fixed a bug that caused `Console`'s `formatted_traceback` being truncated
+  unexpectedly when `filename` is specified.
+  {pr}`4905`
+
+- {{ Fix }} Locked `PyodideConsole.runcode` to block `loadPackagesFromImports`.
+  {pr}`4905`
+
 ### Packages
 
 - Upgraded `scikit-learn` to 1.5 {pr}`4823`

src/py/pyodide/console.py

@@ -405,18 +405,21 @@ class Console:
                 res.set_result(fut.result())
             res = None
 
-        ensure_future(self.runcode(source, code)).add_done_callback(done_cb)
+        ensure_future(self._runcode_with_lock(source, code)).add_done_callback(done_cb)
         return res
 
+    async def _runcode_with_lock(self, source: str, code: CodeRunner) -> Any:
+        async with self._lock:
+            return await self.runcode(source, code)
+
     async def runcode(self, source: str, code: CodeRunner) -> Any:
         """Execute a code object and return the result."""
-        async with self._lock:
+        with self.redirect_streams():
-            with self.redirect_streams():
+            try:
-                try:
+                return await code.run_async(self.globals)
-                    return await code.run_async(self.globals)
+            finally:
-                finally:
+                sys.stdout.flush()
-                    sys.stdout.flush()
+                sys.stderr.flush()
-                    sys.stderr.flush()
 
     def formatsyntaxerror(self, e: Exception) -> str:
         """Format the syntax error that just occurred.
@@ -435,7 +438,7 @@ class Console:
         kept_frames = 0
         # Try to trim out stack frames inside our code
         for frame, _ in traceback.walk_tb(tb):
-            keep_frames = keep_frames or frame.f_code.co_filename == "<console>"
+            keep_frames = keep_frames or frame.f_code.co_filename == self.filename
             keep_frames = keep_frames or frame.f_code.co_filename == "<exec>"
             if keep_frames:
                 kept_frames += 1

src/tests/test_console.py

@@ -288,6 +288,7 @@ def test_nonpersistent_redirection(safe_sys_redirections):
     asyncio.run(test())
 
 
+@pytest.mark.asyncio
 async def test_compile_optimize():
     from pyodide.console import Console
 
@@ -300,6 +301,29 @@ async def test_compile_optimize():
     assert await console.push("f.__doc__") is None
 
 
+@pytest.mark.asyncio
+async def test_console_filename():
+    from pyodide.console import Console
+
+    for filename in ("<console>", "<exec>", "other"):
+        future = Console(filename=filename).push("assert 0")
+        with pytest.raises(AssertionError):
+            await future
+        assert isinstance(future.formatted_error, str)
+        assert f'File "{filename}", line 1, in <module>' in future.formatted_error
+
+
+@pytest.mark.skip_refcount_check
+@run_in_pyodide
+async def test_pyodide_console_runcode_locked(selenium):
+    from pyodide.console import PyodideConsole
+
+    console = PyodideConsole()
+
+    console.push("import micropip")
+    await console.push("micropip")
+
+
 @pytest.mark.skip_refcount_check
 @run_in_pyodide
 async def test_console_imports(selenium):