fix #502: change lexing priority of walrus operator

CHANGELOG.md

@@ -8,6 +8,7 @@ All notable changes to this project will be documented in this file.
 
 -   Adds support for the `map<...>` type declaration syntax from Athena. ([#500](https://github.com/tconbeer/sqlfmt/issues/500) - thank you for the issue and fix, [@benjamin-awd](https://github.com/benjamin-awd)!)
 -   Fixes a bug where nested dicts inside jinja expressions (e.g., `{{ {'a': {'b': 1}} }}`) could cause parsing errors ([#471](https://github.com/tconbeer/sqlfmt/issues/500) - thank you [@rparvathaneni-sc](https://github.com/rparvathaneni-sc) and [@benjamin-awd](https://github.com/benjamin-awd)!). This fix introduces a dependency on jinja2 > v3.0.
+-   Fixes a bug in the lexing logic that prevented the walrus operator (`:=`) from being lexed as a single token ([#502](https://github.com/tconbeer/sqlfmt/issues/502) - thank you [@federico-hero](https://github.com/federico-hero)!).
 
 
 ## [0.20.0] - 2023-09-25

src/sqlfmt/rules/core.py

@@ -91,6 +91,12 @@
         pattern=group(r"::"),
         action=partial(actions.add_node_to_buffer, token_type=TokenType.DOUBLE_COLON),
     ),
+    Rule(
+        name="walrus",
+        priority=421,
+        pattern=group(r":="),
+        action=partial(actions.add_node_to_buffer, token_type=TokenType.OPERATOR),
+    ),
     Rule(
         name="colon",
         priority=430,
@@ -183,7 +189,7 @@
             r"[*+?]?\?",  # regex greedy/non-greedy, also ?
             r"!!",  # negate text match
             r"%%",  # psycopg escaped mod operator
-            r"[+\-*/%&|^=<>:#!]=?",  # singles
+            r"[+\-*/%&|^=<>#!]=?",  # singles
         ),
         action=partial(actions.add_node_to_buffer, token_type=TokenType.OPERATOR),
     ),

tests/data/unformatted/131_assignment_statement.sql

@@ -0,0 +1,7 @@
+select partman.create_parent( 'public.deliveries_finished', 'created_at', 'native', 'daily', p_premake := 20) ;
+)))))__SQLFMT_OUTPUT__(((((
+select
+    partman.create_parent(
+        'public.deliveries_finished', 'created_at', 'native', 'daily', p_premake := 20
+    )
+;

tests/functional_tests/test_general_formatting.py

@@ -47,6 +47,7 @@
         "unformatted/128_double_slash_comments.sql",
         "unformatted/129_duckdb_joins.sql",
         "unformatted/130_athena_data_types.sql",
+        "unformatted/131_assignment_statement.sql",
         "unformatted/200_base_model.sql",
         "unformatted/201_basic_snapshot.sql",
         "unformatted/202_unpivot_macro.sql",

tests/unit_tests/test_rule.py

@@ -68,6 +68,7 @@ def get_rule(ruleset: List[Rule], rule_name: str) -> Rule:
         (CORE, "bracket_open", "["),
         (CORE, "bracket_close", ")"),
         (CORE, "double_colon", "::"),
+        (CORE, "walrus", ":="),
         (CORE, "colon", ":"),
         (CORE, "semicolon", ";"),
         (CORE, "operator", "+"),