move registry into own files

browser_cli/cli.py

@@ -34,6 +34,7 @@ from browser_cli.client import (
     save_remote_token,
 )
 from browser_cli.platform import install_base_dir, is_windows
+from browser_cli.registry import load_registry
 
 console = Console()
 
@@ -231,10 +232,7 @@ def clients_group(ctx):
     else:
         profiles: dict[str, str] = {}
         if REGISTRY_PATH.exists():
-            try:
-                profiles = json.loads(REGISTRY_PATH.read_text())
-            except Exception:
-                pass
+            profiles = load_registry(REGISTRY_PATH)
 
         for profile_name, sock_path in profiles.items():
             display_profile = display_browser_name(profile_name, sock_path)

browser_cli/client.py

@@ -19,6 +19,7 @@ from pathlib import Path
 from typing import Any
 
 from browser_cli.platform import endpoint_for_alias, is_windows, registry_path
+from browser_cli.registry import load_registry
 
 REGISTRY_PATH = registry_path()
 REMOTE_REGISTRY_PATH = Path(os.environ.get("XDG_CONFIG_HOME", Path.home() / ".config")) / "browser-cli" / "remotes.json"
@@ -118,10 +119,7 @@ def _remote_browser_targets() -> list[BrowserTarget]:
 def active_browser_targets(*, include_remotes: bool = True) -> list[BrowserTarget]:
     targets: list[BrowserTarget] = []
     if REGISTRY_PATH.exists():
-        try:
-            reg = json.loads(REGISTRY_PATH.read_text())
-        except Exception:
-            reg = {}
+        reg = load_registry(REGISTRY_PATH)
         targets.extend(
             BrowserTarget(profile=profile, display_name=display_browser_name(profile, sock_path), socket_path=sock_path)
             for profile, sock_path in _active_endpoints(reg).items()
@@ -137,12 +135,9 @@ def _resolve_socket(profile: str | None = None) -> str:
 
     if target:
         if REGISTRY_PATH.exists():
-            try:
-                reg = json.loads(REGISTRY_PATH.read_text())
-                if target in reg:
-                    return reg[target]
-            except Exception:
-                pass
+            reg = load_registry(REGISTRY_PATH)
+            if target in reg:
+                return reg[target]
         return endpoint_for_alias(target)
 
     # Auto-detect: error when multiple browser instances are active

browser_cli/native_host.py

@@ -18,6 +18,7 @@ from multiprocessing.connection import Listener
 from pathlib import Path
 
 from browser_cli.platform import DEFAULT_ALIAS, endpoint_for_alias, is_windows, registry_path, runtime_dir
+from browser_cli.registry import update_registry
 
 SOCKET_PATH: str = ""          # set after hello handshake
 PENDING: dict[str, queue.Queue] = {}
@@ -67,20 +68,14 @@ def write_native_message(stream, msg: dict) -> None:
 
 def _registry_add(alias: str, sock_path: str) -> None:
     try:
-        reg = json.loads(REGISTRY_PATH.read_text()) if REGISTRY_PATH.exists() else {}
-        reg[alias] = sock_path
-        REGISTRY_PATH.write_text(json.dumps(reg))
+        update_registry(alias, sock_path, REGISTRY_PATH)
     except Exception:
         pass
 
 
 def _registry_remove(alias: str) -> None:
     try:
-        if not REGISTRY_PATH.exists():
-            return
-        reg = json.loads(REGISTRY_PATH.read_text())
-        reg.pop(alias, None)
-        REGISTRY_PATH.write_text(json.dumps(reg))
+        update_registry(alias, None, REGISTRY_PATH)
     except Exception:
         pass
 

browser_cli/registry.py

@@ -0,0 +1,99 @@
+"""Runtime registry helpers for active browser-cli native host endpoints."""
+import contextlib
+import json
+import os
+import tempfile
+from pathlib import Path
+from typing import Iterator
+
+from browser_cli.platform import registry_path
+
+REGISTRY_PATH = registry_path()
+
+@contextlib.contextmanager
+def _file_lock(path: Path) -> Iterator[None]:
+    """Best-effort cross-process lock for registry read/modify/write updates."""
+    path.parent.mkdir(mode=0o700, parents=True, exist_ok=True)
+    lock_path = path.with_suffix(path.suffix + ".lock")
+    with lock_path.open("a+") as lock_file:
+        if os.name == "nt":
+            try:
+                import msvcrt
+
+                msvcrt.locking(lock_file.fileno(), msvcrt.LK_LOCK, 1)
+                yield
+            finally:
+                try:
+                    msvcrt.locking(lock_file.fileno(), msvcrt.LK_UNLCK, 1)
+                except OSError:
+                    pass
+        else:
+            try:
+                import fcntl
+
+                fcntl.flock(lock_file.fileno(), fcntl.LOCK_EX)
+                yield
+            finally:
+                try:
+                    fcntl.flock(lock_file.fileno(), fcntl.LOCK_UN)
+                except OSError:
+                    pass
+
+def _coerce_registry(data) -> dict[str, str]:
+    if not isinstance(data, dict):
+        return {}
+    return {str(alias): str(endpoint) for alias, endpoint in data.items() if alias and endpoint}
+
+def load_registry(path: Path | None = None) -> dict[str, str]:
+    """Load the active browser registry.
+
+    Older native hosts wrote this file non-atomically, so tolerate trailing
+    garbage from interrupted/concurrent writes and keep the first valid JSON
+    object when possible.
+    """
+    registry = path or REGISTRY_PATH
+    if not registry.exists():
+        return {}
+    try:
+        text = registry.read_text(encoding="utf-8")
+    except OSError:
+        return {}
+    if not text.strip():
+        return {}
+    try:
+        return _coerce_registry(json.loads(text))
+    except json.JSONDecodeError:
+        try:
+            data, _ = json.JSONDecoder().raw_decode(text)
+            return _coerce_registry(data)
+        except json.JSONDecodeError:
+            return {}
+
+def save_registry(data: dict[str, str], path: Path | None = None) -> None:
+    """Atomically write the active browser registry."""
+    registry = path or REGISTRY_PATH
+    registry.parent.mkdir(mode=0o700, parents=True, exist_ok=True)
+    payload = json.dumps(_coerce_registry(data), sort_keys=True)
+    fd, tmp_name = tempfile.mkstemp(prefix=registry.name + ".", suffix=".tmp", dir=registry.parent)
+    try:
+        with os.fdopen(fd, "w", encoding="utf-8") as tmp:
+            tmp.write(payload)
+            tmp.flush()
+            os.fsync(tmp.fileno())
+        os.replace(tmp_name, registry)
+    finally:
+        try:
+            os.unlink(tmp_name)
+        except FileNotFoundError:
+            pass
+
+def update_registry(alias: str, endpoint: str | None, path: Path | None = None) -> None:
+    """Add/update an alias, or remove it when endpoint is None."""
+    registry = path or REGISTRY_PATH
+    with _file_lock(registry):
+        data = load_registry(registry)
+        if endpoint is None:
+            data.pop(alias, None)
+        else:
+            data[alias] = endpoint
+        save_registry(data, registry)

tests/test_cli.py

@@ -141,6 +141,25 @@ def test_clients_exits_cleanly_when_registry_is_missing():
     assert result.exit_code == 1
     assert "No browser clients found" in result.output
 
+
+def test_clients_reads_registry_with_trailing_garbage(tmp_path):
+    registry_path = tmp_path / "registry.json"
+    registry_path.write_text('{"main": "/tmp/.browser_cli/main.sock"}"}', encoding="utf-8")
+
+    def fake_send_command(command, args=None, profile=None):
+        assert command == "clients.list"
+        assert profile == "main"
+        return [{"profile": "main", "name": "Chrome", "version": "1", "extensionVersion": "0.8.2"}]
+
+    with patch("browser_cli.cli.REGISTRY_PATH", registry_path), patch(
+        "browser_cli.cli.send_command", side_effect=fake_send_command
+    ):
+        result = CliRunner().invoke(main, ["clients"])
+
+    assert result.exit_code == 0
+    assert "main" in result.output
+    assert "0.8.2" in result.output
+
 def test_clients_remote_uses_remote_endpoint_without_local_registry():
     def fake_send_command(command, args=None, profile=None):
         assert command == "clients.list"

tests/test_registry.py

@@ -0,0 +1,30 @@
+import json
+
+from browser_cli.registry import load_registry, save_registry, update_registry
+
+
+def test_load_registry_tolerates_trailing_garbage_from_old_non_atomic_writes(tmp_path):
+    registry = tmp_path / "registry.json"
+    registry.write_text('{"main": "/tmp/.browser_cli/main.sock"}"}', encoding="utf-8")
+
+    assert load_registry(registry) == {"main": "/tmp/.browser_cli/main.sock"}
+
+
+def test_update_registry_repairs_corrupted_registry_and_preserves_entries(tmp_path):
+    registry = tmp_path / "registry.json"
+    registry.write_text('{"main": "/tmp/.browser_cli/main.sock"}"}', encoding="utf-8")
+
+    update_registry("work", "/tmp/.browser_cli/work.sock", registry)
+
+    assert json.loads(registry.read_text(encoding="utf-8")) == {
+        "main": "/tmp/.browser_cli/main.sock",
+        "work": "/tmp/.browser_cli/work.sock",
+    }
+
+
+def test_save_registry_writes_valid_json_atomically(tmp_path):
+    registry = tmp_path / "registry.json"
+
+    save_registry({"main": "/tmp/main.sock"}, registry)
+
+    assert json.loads(registry.read_text(encoding="utf-8")) == {"main": "/tmp/main.sock"}