python · pablogsal · Feb 28, 2026 · Feb 28, 2026 · Feb 28, 2026
@@ -94,6 +94,7 @@ def export(self, filename=None):
            filename: Ignored (binary files are written incrementally)
        """
        self._writer.finalize()
+        return True

    @property
    def total_samples(self):

@@ -660,10 +660,14 @@ def _handle_output(collector, args, pid, mode):
            filename = os.path.join(args.outfile, _generate_output_filename(args.format, pid))
        else:
            filename = args.outfile or _generate_output_filename(args.format, pid)
-        collector.export(filename)
+        export_ok = collector.export(filename)

        # Auto-open browser for HTML output if --browser flag is set
-        if args.format in ('flamegraph', 'heatmap') and getattr(args, 'browser', False):
+        if (
+            export_ok
+            and args.format in ('flamegraph', 'heatmap')
+            and getattr(args, 'browser', False)
+        ):
            _open_in_browser(filename)


@@ -1203,10 +1207,14 @@ def progress_callback(current, total):
                collector.print_stats(sort_mode, limit, not args.no_summary, PROFILING_MODE_WALL)
        else:
            filename = args.outfile or _generate_output_filename(args.format, os.getpid())
-            collector.export(filename)
+            export_ok = collector.export(filename)

            # Auto-open browser for HTML output if --browser flag is set
-            if args.format in ('flamegraph', 'heatmap') and getattr(args, 'browser', False):
+            if (
+                export_ok
+                and args.format in ('flamegraph', 'heatmap')
+                and getattr(args, 'browser', False)
+            ):
                _open_in_browser(filename)

        print(f"Replayed {count} samples")

@@ -81,7 +81,11 @@ def collect_failed_sample(self):

    @abstractmethod
    def export(self, filename):
-        """Export collected data to a file."""
+        """Export collected data.
+
+        Returns:
+            bool: True if output was generated, False if there was no data to export.
+        """

    @staticmethod
    def _filter_internal_frames(frames):

@@ -701,6 +701,7 @@ def spin():
        print(
            f"Open in Firefox Profiler: https://profiler.firefox.com/"
        )
+        return True

    def _build_marker_schema(self):
        """Build marker schema definitions for Firefox Profiler."""

@@ -714,7 +714,7 @@ def export(self, output_path):
        """
        if not self.file_samples:
            print("Warning: No heatmap data to export")
-            return
+            return False

        try:
            output_dir = self._prepare_output_directory(output_path)
@@ -728,6 +728,7 @@ def export(self, output_path):
            self._generate_index_html(output_dir / 'index.html', file_stats)

            self._print_export_summary(output_dir, file_stats)
+            return True

        except Exception as e:
            print(f"Error: Failed to export heatmap: {e}")

@@ -61,6 +61,7 @@ def collect(self, stack_frames, timestamps_us=None):
    def export(self, filename):
        self.create_stats()
        self._dump_stats(filename)
+        return True

    def _dump_stats(self, file):
        stats_with_marker = dict(self.stats)

@@ -61,6 +61,7 @@ def export(self, filename):
            for stack, count in lines:
                f.write(f"{stack} {count}\n")
        print(f"Collapsed stack output written to {filename}")
+        return True


 class FlamegraphCollector(StackTraceCollector):
@@ -157,14 +158,15 @@ def export(self, filename):
            print(
                "Warning: No functions found in profiling data. Check if sampling captured any data."
            )
-            return
+            return False

        html_content = self._create_flamegraph_html(flamegraph_data)

        with open(filename, "w", encoding="utf-8") as f:
            f.write(html_content)

        print(f"Flamegraph saved to: {filename}")
+        return True

    @staticmethod
    @functools.lru_cache(maxsize=None)

@@ -4,6 +4,7 @@
 import subprocess
 import sys
 import unittest
+from types import SimpleNamespace
 from unittest import mock

 try:
@@ -15,7 +16,7 @@

 from test.support import is_emscripten, requires_remote_subprocess_debugging

-from profiling.sampling.cli import main
+from profiling.sampling.cli import _handle_output, main
 from profiling.sampling.errors import SamplingScriptNotFoundError, SamplingModuleNotFoundError, SamplingUnknownProcessError

 class TestSampleProfilerCLI(unittest.TestCase):
@@ -700,6 +701,24 @@ def test_async_aware_incompatible_with_all_threads(self):
        self.assertIn("--all-threads", error_msg)
        self.assertIn("incompatible with --async-aware", error_msg)

+    def test_handle_output_browser_not_opened_when_export_fails(self):
+        collector = mock.MagicMock()
+        collector.export.return_value = False
+        args = SimpleNamespace(
+            format="flamegraph",
+            outfile="profile.html",
+            browser=True,
+        )
+
+        with (
+            mock.patch("profiling.sampling.cli.os.path.isdir", return_value=False),
+            mock.patch("profiling.sampling.cli._open_in_browser") as mock_open,
+        ):
+            _handle_output(collector, args, pid=12345, mode=0)
+
+        collector.export.assert_called_once_with("profile.html")
+        mock_open.assert_not_called()
+
    @unittest.skipIf(is_emscripten, "subprocess not available")
    def test_run_nonexistent_script_exits_cleanly(self):
        """Test that running a non-existent script exits with a clean error."""