feat: support Snowflake UNION BY NAME (6994)

.sqlfluff-sha

@@ -1 +1 @@
-02cda72fb6c5613079e0a0a0cd1146ba26e47167
+59bf84573e526900b6d891c0bc05762e7e0ab3be

crates/lib-dialects/src/snowflake.rs

@@ -11846,6 +11846,12 @@ pub fn dialect(config: Option<&Value>) -> Dialect {
                 ])
                 .config(|this| this.optional())
                 .to_matchable(),
+                Sequence::new(vec![
+                    Ref::keyword("BY").to_matchable(),
+                    Ref::keyword("NAME").to_matchable(),
+                ])
+                .config(|this| this.optional())
+                .to_matchable(),
             ])
             .to_matchable(),
             Sequence::new(vec![

crates/lib-dialects/test/fixtures/dialects/snowflake/sqlfluff/select_union.sql

@@ -2,3 +2,14 @@ SELECT 1
 UNION
 SELECT 2
 ORDER BY 1
+;
+
+SELECT 1 AS foo
+UNION ALL BY NAME
+SELECT 2 AS foo
+;
+
+SELECT 1 AS foo
+UNION BY NAME
+SELECT 2 AS foo
+;

crates/lib-dialects/test/fixtures/dialects/snowflake/sqlfluff/select_union.yml

@@ -17,3 +17,55 @@ file:
       - keyword: ORDER
       - keyword: BY
       - numeric_literal: '1'
+- statement_terminator: ;
+- statement:
+  - set_expression:
+    - select_statement:
+      - select_clause:
+        - keyword: SELECT
+        - select_clause_element:
+          - numeric_literal: '1'
+          - alias_expression:
+            - alias_operator:
+              - keyword: AS
+            - naked_identifier: foo
+    - set_operator:
+      - keyword: UNION
+      - keyword: ALL
+      - keyword: BY
+      - keyword: NAME
+    - select_statement:
+      - select_clause:
+        - keyword: SELECT
+        - select_clause_element:
+          - numeric_literal: '2'
+          - alias_expression:
+            - alias_operator:
+              - keyword: AS
+            - naked_identifier: foo
+- statement_terminator: ;
+- statement:
+  - set_expression:
+    - select_statement:
+      - select_clause:
+        - keyword: SELECT
+        - select_clause_element:
+          - numeric_literal: '1'
+          - alias_expression:
+            - alias_operator:
+              - keyword: AS
+            - naked_identifier: foo
+    - set_operator:
+      - keyword: UNION
+      - keyword: BY
+      - keyword: NAME
+    - select_statement:
+      - select_clause:
+        - keyword: SELECT
+        - select_clause_element:
+          - numeric_literal: '2'
+          - alias_expression:
+            - alias_operator:
+              - keyword: AS
+            - naked_identifier: foo
+- statement_terminator: ;