fix: address Bash streaming review feedback

tests/test_bash_streaming.py

@@ -0,0 +1,185 @@
+import subprocess
+import sys
+import time
+from unittest.mock import patch
+
+import pytest
+
+from agent.tools.bash.bash import Bash
+
+
+posix_only = pytest.mark.skipif(Bash._IS_WIN, reason="POSIX shell command")
+windows_only = pytest.mark.skipif(not Bash._IS_WIN, reason="Windows integration test")
+
+
+def _windows_pid_command(pid_file):
+    path = str(pid_file).replace("\\", "\\\\")
+    return (
+        f'"{sys.executable}" -c '
+        f'"import os,time;open(r\'{path}\',\'w\').write(str(os.getpid()));time.sleep(30)"'
+    )
+
+
+def _windows_pid_is_running(pid):
+    result = subprocess.run(
+        ["tasklist", "/FI", f"PID eq {pid}", "/FO", "CSV", "/NH"],
+        capture_output=True,
+        text=True,
+        errors="replace",
+    )
+    return f'"{pid}"' in result.stdout
+
+
+def _windows_kill_pid_file(pid_file):
+    if pid_file.exists():
+        subprocess.run(
+            ["taskkill", "/F", "/PID", pid_file.read_text()],
+            capture_output=True,
+        )
+
+
+@posix_only
+def test_fast_command_returns_output_without_progress(tmp_path):
+    tool = Bash({"cwd": str(tmp_path)})
+    progress = []
+    tool.progress_callback = progress.append
+
+    result = tool.execute({"command": "printf fast"})
+
+    assert result.status == "success"
+    assert result.result["output"] == "fast"
+    assert progress == []
+
+
+@posix_only
+def test_timeout_returns_promptly(tmp_path):
+    tool = Bash({"cwd": str(tmp_path)})
+    started = time.monotonic()
+
+    result = tool.execute({"command": "sleep 10", "timeout": 1})
+
+    assert result.status == "error"
+    assert "timed out after 1 seconds" in result.result
+    assert time.monotonic() - started < 3
+
+
+@posix_only
+def test_background_process_holding_pipe_does_not_hang(tmp_path):
+    tool = Bash({"cwd": str(tmp_path)})
+    started = time.monotonic()
+
+    result = tool.execute({"command": "sleep 10 & printf done", "timeout": 3})
+
+    assert result.status == "success"
+    assert result.result["output"] == "done"
+    assert time.monotonic() - started < 7
+
+
+@posix_only
+def test_output_without_trailing_newline_streams_progress(tmp_path):
+    tool = Bash({"cwd": str(tmp_path)})
+    progress = []
+    tool.progress_callback = progress.append
+
+    result = tool.execute({
+        "command": "for i in 1 2 3 4 5; do printf .; sleep 0.3; done",
+        "timeout": 5,
+    })
+
+    assert result.status == "success"
+    assert result.result["output"] == "....."
+    assert progress
+    assert progress[-1].endswith(".")
+
+
+def test_windows_kill_uses_taskkill_for_process_tree():
+    tool = Bash()
+    process = type("Process", (), {"pid": 1234, "poll": lambda self: None, "kill": lambda self: None})()
+
+    with patch.object(tool, "_IS_WIN", True), patch.object(subprocess, "run") as run:
+        run.return_value.returncode = 0
+        tool._kill_process(process)
+
+    run.assert_called_once_with(
+        ["taskkill", "/F", "/T", "/PID", "1234"],
+        capture_output=True,
+        timeout=5,
+    )
+
+
+def test_windows_kill_falls_back_when_taskkill_fails():
+    tool = Bash()
+    process = type("Process", (), {"pid": 1234, "poll": lambda self: None, "kill": lambda self: None})()
+
+    with patch.object(tool, "_IS_WIN", True), \
+            patch.object(subprocess, "run", side_effect=OSError), \
+            patch.object(process, "kill") as kill:
+        tool._kill_process(process)
+
+    kill.assert_called_once()
+
+
+@windows_only
+def test_windows_timeout_kills_process_tree(tmp_path):
+    pid_file = tmp_path / "timeout-child.pid"
+    child_command = _windows_pid_command(pid_file)
+    tool = Bash({"cwd": str(tmp_path)})
+    started = time.monotonic()
+
+    try:
+        result = tool.execute({
+            "command": f'start "" /b {child_command} & ping -n 30 127.0.0.1 >nul',
+            "timeout": 1,
+        })
+
+        assert result.status == "error"
+        assert "timed out after 1 seconds" in result.result
+        assert time.monotonic() - started < 8
+        assert pid_file.exists()
+        time.sleep(0.5)
+        assert not _windows_pid_is_running(pid_file.read_text())
+    finally:
+        _windows_kill_pid_file(pid_file)
+
+
+@windows_only
+def test_windows_long_running_command_streams_progress(tmp_path):
+    tool = Bash({"cwd": str(tmp_path)})
+    progress = []
+    tool.progress_callback = progress.append
+
+    result = tool.execute({
+        "command": (
+            f'"{sys.executable}" -u -c '
+            '"import sys,time; '
+            "[(sys.stdout.write('.'),sys.stdout.flush(),time.sleep(0.3)) "
+            'for _ in range(5)]"'
+        ),
+        "timeout": 5,
+    })
+
+    assert result.status == "success"
+    assert result.result["output"] == "....."
+    assert progress
+    assert progress[-1].endswith(".")
+
+
+@windows_only
+def test_windows_background_process_holding_pipe_does_not_hang(tmp_path):
+    pid_file = tmp_path / "background-child.pid"
+    child_command = _windows_pid_command(pid_file)
+    tool = Bash({"cwd": str(tmp_path)})
+    started = time.monotonic()
+
+    try:
+        result = tool.execute({
+            "command": f'start "" /b {child_command} & echo done',
+            "timeout": 3,
+        })
+
+        assert result.status == "success"
+        assert result.result["output"].strip() == "done"
+        assert time.monotonic() - started < 8
+        assert pid_file.exists()
+    finally:
+        _windows_kill_pid_file(pid_file)