Allow defining a json file with preferred aliases (#1382)

* fix psycopg.sql.Identifier in \ev handling (#1384)

* Allow defining a json file with preferred aliases

At $WORK we have a lot of tables with names like `foo_noun_verb` or
`foo_noun_related-noun_verb` and so while the default aliasing is very
helpful for shortening unwieldy names we do end up with lots of aliases
like `LEFT JOIN fnv on fnv2.id = fnv.fnv2_id`

This change will allow defining a json file of preferred aliases

```
> cat ~/.config/pgcli/aliases.json
{
    "foo_user": "user",
    "foo_user_group": "user_group"
}
```

so the alias suggestion for `SELECT * FROM foo_user` will be `SELECT * FROM foo_user AS user`
instead of the default `SELECT * FROM foo_user AS fu`

* When cannot open or parse alias_map_file raise error

Raise a (hopefully) helpful exception when the alias_map_file cannot be
parsed or does not exist

* Add tests for load_alias_map_file

* Add tests for generate_alias

* Update AUTHORS file

* Remove comment.

Discussed this on the PR with a project maintainer

---------

Co-authored-by: Andy Schoenberger <akschoenberger@gmail.com>
Co-authored-by: Rob B <rob@example.com>
Co-authored-by: Irina Truong <i.chernyavska@gmail.com>

1 files changed, 76 insertions, 0 deletions

diff --git a/tests/test_pgcompleter.py b/tests/test_pgcompleter.py
new file mode 100644
index 00000000..909fa0b7
--- /dev/null
+++ b/tests/test_pgcompleter.py
@@ -0,0 +1,76 @@
+import pytest
+from pgcli import pgcompleter
+
+
+def test_load_alias_map_file_missing_file():
+    with pytest.raises(
+        pgcompleter.InvalidMapFile,
+        match=r"Cannot read alias_map_file - /path/to/non-existent/file.json does not exist$",
+    ):
+        pgcompleter.load_alias_map_file("/path/to/non-existent/file.json")
+
+
+def test_load_alias_map_file_invalid_json(tmp_path):
+    fpath = tmp_path / "foo.json"
+    fpath.write_text("this is not valid json")
+    with pytest.raises(pgcompleter.InvalidMapFile, match=r".*is not valid json$"):
+        pgcompleter.load_alias_map_file(str(fpath))
+
+
+@pytest.mark.parametrize(
+    "table_name, alias",
+    [
+        ("SomE_Table", "SET"),
+        ("SOmeTabLe", "SOTL"),
+        ("someTable", "T"),
+    ],
+)
+def test_generate_alias_uses_upper_case_letters_from_name(table_name, alias):
+    assert pgcompleter.generate_alias(table_name) == alias
+
+
+@pytest.mark.parametrize(
+    "table_name, alias",
+    [
+        ("some_tab_le", "stl"),
+        ("s_ome_table", "sot"),
+        ("sometable", "s"),
+    ],
+)
+def test_generate_alias_uses_first_char_and_every_preceded_by_underscore(
+    table_name, alias
+):
+    assert pgcompleter.generate_alias(table_name) == alias
+
+
+@pytest.mark.parametrize(
+    "table_name, alias_map, alias",
+    [
+        ("some_table", {"some_table": "my_alias"}, "my_alias"),
+    ],
+)
+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",
+    [
+        ("SomeTable", {"SomeTable": "my_alias"}, "my_alias"),
+    ],
+)
+def test_generate_alias_prefers_alias_over_upper_case_name(
+    table_name, alias_map, alias
+):
+    assert pgcompleter.generate_alias(table_name, alias_map) == alias
+
+
+@pytest.mark.parametrize(
+    "table_name, alias",
+    [
+        ("Some_tablE", "SE"),
+        ("SomeTab_le", "ST"),
+    ],
+)
+def test_generate_alias_prefers_upper_case_name_over_underscore_name(table_name, alias):
+    assert pgcompleter.generate_alias(table_name) == alias