Suggest columns after GROUP BY (#1599)

The completion engine offers columns after SELECT, WHERE, HAVING,
ORDER BY and DISTINCT, but GROUP BY was missing from that list, so
`SELECT ... FROM tbl GROUP BY <tab>` fell through to FROM-clause
handling and suggested tables/schemas instead of columns.

Add "group by" to the keyword tuple so it suggests columns like
ORDER BY already does, and extend the existing alias tests to cover it.

Author: Kynde

AUTHORS

@@ -148,6 +148,7 @@ Contributors:
     * Charalampos Stratakis
     * Laszlo Bimba (bimlas)
     * Anjanna
+    * Tommi Kyntölä (kynde)
 
 Creator:
 --------

changelog.rst

@@ -20,6 +20,7 @@ Bug fixes:
 * Fix trailing SQL comments preventing query submission and execution.
     * ``SELECT 1; -- note`` now submits correctly in multiline mode
     * ``rstrip(";")`` in ``pgexecute.py`` now handles comments after the semicolon
+* Suggest columns after `GROUP BY`, like `ORDER BY` already does.    
 
 4.4.0 (2025-12-24)
 ==================

pgcli/packages/sqlcompletion.py

@@ -383,7 +383,7 @@ def suggest_based_on_last_token(token, stmt):
         # E.g. 'UPDATE foo SET'
         return (Column(table_refs=stmt.get_tables(), local_tables=stmt.local_tables),)
 
-    elif token_v in ("select", "where", "having", "order by", "distinct"):
+    elif token_v in ("select", "where", "having", "group by", "order by", "distinct"):
         return _suggest_expression(token_v, stmt)
     elif token_v == "as":
         # Don't suggest anything for aliases

tests/test_sqlcompletion.py

@@ -221,6 +221,11 @@ def test_distinct_suggests_cols(text):
             "SELECT * FROM tbl x JOIN tbl1 y ORDER BY ",
             "ORDER BY",
         ),
+        (
+            "SELECT * FROM tbl x JOIN tbl1 y GROUP BY ",
+            "SELECT * FROM tbl x JOIN tbl1 y GROUP BY ",
+            "GROUP BY",
+        ),
     ],
 )
 def test_distinct_and_order_by_suggestions_with_aliases(text, text_before, last_keyword):
@@ -247,6 +252,10 @@ def test_distinct_and_order_by_suggestions_with_aliases(text, text_before, last_
             "SELECT * FROM tbl x JOIN tbl1 y ORDER BY x.",
             "SELECT * FROM tbl x JOIN tbl1 y ORDER BY x.",
         ),
+        (
+            "SELECT * FROM tbl x JOIN tbl1 y GROUP BY x.",
+            "SELECT * FROM tbl x JOIN tbl1 y GROUP BY x.",
+        ),
     ],
 )
 def test_distinct_and_order_by_suggestions_with_alias_given(text, text_before):