Read alias_map_file as UTF-8 instead of the locale encoding

AUTHORS

@@ -157,6 +157,7 @@ Contributors:
     * Chris (ChrisJr404)
     * Pieter Ouwerkerk (pouwerkerk)
     * VXNCXNX
+    * Wei-Lun Li (b84330808)
 
     * jackwalkerlabs (Codex-assisted)
 

changelog.rst

@@ -12,6 +12,8 @@ Bug fixes:
 ----------
 * Fix the development setup instructions to activate the ``.venv`` directory
   created by ``uv venv``.
+* Read ``alias_map_file`` as UTF-8 (with or without a BOM) instead of the
+  locale encoding, which made non-ASCII aliases fail on Windows.
 
 4.7.1 (2026-09-20)
 ==================

pgcli/pgcompleter.py

@@ -84,7 +84,9 @@ class InvalidMapFile(ValueError):
 
 def load_alias_map_file(path):
     try:
-        with open(path) as fo:
+        # Read bytes so that json detects the encoding (UTF-8, with or without
+        # a BOM) instead of using the locale encoding (e.g. cp932 on Windows).
+        with open(path, "rb") as fo:
             alias_map = json.load(fo)
     except FileNotFoundError as err:
         raise InvalidMapFile(f"Cannot read alias_map_file - {err.filename} does not exist")

tests/test_pgcompleter.py

@@ -25,6 +25,15 @@ def test_load_alias_map_file_invalid_json(tmp_path):
         pgcompleter.load_alias_map_file(str(fpath))
 
 
+@pytest.mark.parametrize("encoding", ["utf-8", "utf-8-sig"])
+def test_load_alias_map_file_reads_utf8(tmp_path, encoding):
+    # JSON files are UTF-8, whatever the locale encoding is (e.g. cp932 or
+    # cp1252 on Windows). Editors such as Notepad may also add a BOM.
+    fpath = tmp_path / "aliases.json"
+    fpath.write_text('{"注文明細": "om", "café": "c"}', encoding=encoding)
+    assert pgcompleter.load_alias_map_file(str(fpath)) == {"注文明細": "om", "café": "c"}
+
+
 def test_path_completion_filters_files_for_cd(tmp_path, monkeypatch):
     (tmp_path / "folder").mkdir()
     (tmp_path / "file.sql").touch()