Bugfix alias_map_file not being used for table aliases (#1492)

* Add failing test for using configured alias map

The test demonstrates a bug in the PGCompleter class where a configured
alias map file is not used to generate aliases.

* Use configured alias map in PGCompleter

Fixes a bug where this configuration was ignored.

* Update generate_alias docstring

Clarify the behaviour of generate_alias when an alias_map argument is
passed.

* Add "no match in map" test case for generate_alias

Test demonstrates passing an alias_map to generate_alias does not break
generation of aliases for tables not covered within the map file.

* Update AUTHORS file

Credit where credit is due ;)

AUTHORS

@@ -137,6 +137,7 @@ Contributors:
     * Chris Rose (offbyone/offby1)
     * Mathieu Dupuy (deronnax)
     * Chris Novakovic
+    * Josh Lynch (josh-lynch)
 
 Creator:
 --------

changelog.rst

@@ -9,6 +9,7 @@ Features
 Bug fixes:
 ----------
 * Avoid raising `NameError` when exiting unsuccessfully in some cases
+* Use configured `alias_map_file` to generate table aliases if available.
 
 Internal:
 ---------

pgcli/pgcompleter.py

@@ -63,10 +63,17 @@ def Candidate(
 
 
 def generate_alias(tbl, alias_map=None):
-    """Generate a table alias, consisting of all upper-case letters in
-    the table name, or, if there are no upper-case letters, the first letter +
-    all letters preceded by _
-    param tbl - unescaped name of the table to alias
+    """Generate a table alias.
+
+    Given a table name will return an alias for that table using the first of
+    the following options there's a match for.
+
+        1. The predefined alias for table defined in the alias_map.
+        2. All upper-case letters in the table name.
+        3. The first letter of the table name and all letters preceded by _
+
+    :param tbl: unescaped name of the table to alias
+    :param alias_map: optional mapping of predefined table aliases
     """
     if alias_map and tbl in alias_map:
         return alias_map[tbl]
@@ -528,7 +535,7 @@ def get_column_matches(self, suggestion, word_before_cursor):
         scoped_cols = self.populate_scoped_cols(tables, suggestion.local_tables)
 
         def make_cand(name, ref):
-            synonyms = (name, generate_alias(self.case(name)))
+            synonyms = (name, generate_alias(self.case(name), alias_map=self.alias_map))
             return Candidate(qualify(name, ref), 0, "column", synonyms)
 
         def flat_cols():
@@ -601,7 +608,7 @@ def alias(self, tbl, tbls):
         tbl = self.case(tbl)
         tbls = {normalize_ref(t.ref) for t in tbls}
         if self.generate_aliases:
-            tbl = generate_alias(self.unescape_name(tbl))
+            tbl = generate_alias(self.unescape_name(tbl), alias_map=self.alias_map)
         if normalize_ref(tbl) not in tbls:
             return tbl
         elif tbl[0] == '"':
@@ -644,7 +651,7 @@ def get_join_matches(self, suggestion, word_before_cursor):
                 join = "{0} ON {0}.{1} = {2}.{3}".format(
                     c(left.tbl), c(left.col), rtbl.ref, c(right.col)
                 )
-            alias = generate_alias(self.case(left.tbl))
+            alias = generate_alias(self.case(left.tbl), alias_map=self.alias_map)
             synonyms = [
                 join,
                 "{0} ON {0}.{1} = {2}.{3}".format(
@@ -845,7 +852,7 @@ def _make_cand(self, tbl, do_alias, suggestion, arg_mode=None):
         cased_tbl = self.case(tbl.name)
         if do_alias:
             alias = self.alias(cased_tbl, suggestion.table_refs)
-        synonyms = (cased_tbl, generate_alias(cased_tbl))
+        synonyms = (cased_tbl, generate_alias(cased_tbl, alias_map=self.alias_map))
         maybe_alias = (" " + alias) if do_alias else ""
         maybe_schema = (self.case(tbl.schema) + ".") if tbl.schema else ""
         suffix = self._arg_list_cache[arg_mode][tbl.meta] if arg_mode else ""

tests/test_pgcompleter.py

@@ -1,5 +1,7 @@
+import json
 import pytest
 from pgcli import pgcompleter
+import tempfile
 
 
 def test_load_alias_map_file_missing_file():
@@ -47,12 +49,34 @@ def test_generate_alias_uses_first_char_and_every_preceded_by_underscore(
     "table_name, alias_map, alias",
     [
         ("some_table", {"some_table": "my_alias"}, "my_alias"),
+        pytest.param(
+            "some_other_table", {"some_table": "my_alias"}, "sot", id="no_match_in_map"
+        ),
     ],
 )
 def test_generate_alias_can_use_alias_map(table_name, alias_map, alias):
     assert pgcompleter.generate_alias(table_name, alias_map) == alias
 
 
+@pytest.mark.parametrize(
+    "table_name, alias_map, alias",
+    [
+        ("some_table", {"some_table": "my_alias"}, "my_alias"),
+    ],
+)
+def test_pgcompleter_alias_uses_configured_alias_map(table_name, alias_map, alias):
+    with tempfile.NamedTemporaryFile(mode="w", suffix=".json") as alias_map_file:
+        alias_map_file.write(json.dumps(alias_map))
+        alias_map_file.seek(0)
+        completer = pgcompleter.PGCompleter(
+            settings={
+                "generate_aliases": True,
+                "alias_map_file": alias_map_file.name,
+            }
+        )
+        assert completer.alias(table_name, []) == alias
+
+
 @pytest.mark.parametrize(
     "table_name, alias_map, alias",
     [