test(client): cover _to_ws_url scheme/port/path-prefix handling

Helper had no coverage. Pins scheme mapping (http/https/ws/wss/unknown),
port preservation, the path-prefix regression with and without a scheme,
bare-host parsing, trailing-slash dedup, and the empty-url ValueError.

Author: Zawwarsami16

tests/test_client_url.py

@@ -0,0 +1,58 @@
+"""Unit tests for zhub.client._to_ws_url — the http/ws → wss URL builder.
+
+The helper documents that it preserves both the port and any path prefix
+(a hub may be reverse-proxied under e.g. example.com/zhub/). Port was always
+kept; the path prefix used to be dropped whenever a scheme was present, which
+silently routed publishers/clients to the wrong WS endpoint behind a proxy.
+"""
+
+from zhub.client import _to_ws_url
+
+import pytest
+
+
+def test_scheme_to_secure_ws():
+    assert _to_ws_url("https://hub.example.com", "/ws/publish") == "wss://hub.example.com/ws/publish"
+    assert _to_ws_url("http://hub.example.com", "/ws/publish") == "ws://hub.example.com/ws/publish"
+
+
+def test_already_ws_scheme_preserved():
+    assert _to_ws_url("ws://localhost:8080", "/ws/connect") == "ws://localhost:8080/ws/connect"
+    assert _to_ws_url("wss://hub.example.com", "/ws/connect") == "wss://hub.example.com/ws/connect"
+
+
+def test_unknown_scheme_defaults_to_secure():
+    assert _to_ws_url("ftp://hub.example.com", "/ws/publish") == "wss://hub.example.com/ws/publish"
+
+
+def test_port_is_preserved():
+    assert _to_ws_url("https://hub.example.com:9000", "/ws/publish") == "wss://hub.example.com:9000/ws/publish"
+
+
+def test_path_prefix_is_preserved_with_scheme():
+    # regression: the prefix used to be dropped when a scheme was present
+    assert _to_ws_url("https://hub.example.com/zhub", "/ws/publish") == "wss://hub.example.com/zhub/ws/publish"
+
+
+def test_port_and_path_prefix_both_preserved():
+    assert (
+        _to_ws_url("https://hub.example.com:9000/api/zhub", "/ws/connect")
+        == "wss://hub.example.com:9000/api/zhub/ws/connect"
+    )
+
+
+def test_bare_host_accepted():
+    assert _to_ws_url("hub.example.com", "/ws/expose") == "wss://hub.example.com/ws/expose"
+
+
+def test_bare_host_with_prefix_preserved():
+    assert _to_ws_url("hub.example.com/zhub", "/ws/publish") == "wss://hub.example.com/zhub/ws/publish"
+
+
+def test_trailing_slash_does_not_double():
+    assert _to_ws_url("https://hub.example.com/", "/ws/publish") == "wss://hub.example.com/ws/publish"
+
+
+def test_empty_url_raises():
+    with pytest.raises(ValueError):
+        _to_ws_url("", "/ws/publish")