fix: OpenSearch dialect identifier delimiters (#39953)

tests/unit_tests/sql/dialects/opensearch_tests.py

@@ -33,7 +33,8 @@ def test_opensearch_dialect_registered() -> None:
 
 def test_double_quotes_as_identifiers() -> None:
     """
-    Test that double quotes are treated as identifiers, not string literals.
+    Test that double quotes are treated as identifiers, not string literals,
+    and normalized to backticks in output.
     """
     sql = 'SELECT "AvgTicketPrice" FROM "flights"'
     ast = sqlglot.parse_one(sql, OpenSearch)
@@ -42,8 +43,8 @@ def test_double_quotes_as_identifiers() -> None:
         OpenSearch().generate(expression=ast, pretty=True)
         == """
 SELECT
-  "AvgTicketPrice"
-FROM "flights"
+  `AvgTicketPrice`
+FROM `flights`
         """.strip()
     )
 
@@ -69,8 +70,7 @@ WHERE
 
 def test_backticks_as_identifiers() -> None:
     """
-    Test that backticks work as identifiers (MySQL-style).
-    Backticks are normalized to double quotes in output.
+    Test that backticks are accepted as identifiers and preserved on output.
     """
     sql = "SELECT `AvgTicketPrice` FROM `flights`"
     ast = sqlglot.parse_one(sql, OpenSearch)
@@ -79,15 +79,16 @@ def test_backticks_as_identifiers() -> None:
         OpenSearch().generate(expression=ast, pretty=True)
         == """
 SELECT
-  "AvgTicketPrice"
-FROM "flights"
+  `AvgTicketPrice`
+FROM `flights`
         """.strip()
     )
 
 
 def test_mixed_identifier_quotes() -> None:
     """
-    Test mixing double quotes and backticks for identifiers.
+    Test mixing double quotes and backticks for identifiers are all normalized to
+    backticks on output.
     """
     sql = 'SELECT "AvgTicketPrice" AS `AvgTicketPrice` FROM `default`.`flights`'
     ast = sqlglot.parse_one(sql, OpenSearch)
@@ -96,12 +97,26 @@ def test_mixed_identifier_quotes() -> None:
         OpenSearch().generate(expression=ast, pretty=True)
         == """
 SELECT
-  "AvgTicketPrice" AS "AvgTicketPrice"
-FROM "default"."flights"
+  `AvgTicketPrice` AS `AvgTicketPrice`
+FROM `default`.`flights`
         """.strip()
     )
 
 
+def test_alias_with_space() -> None:
+    """
+    Test that an alias containing a space (e.g. a metric key like ``my test``)
+    is preserved as a backtick-quoted identifier through the round-trip.
+    """
+    sql = 'SELECT COUNT(*) AS "my test" FROM `flights`'
+    ast = sqlglot.parse_one(sql, OpenSearch)
+
+    assert (
+        OpenSearch().generate(expression=ast, pretty=False)
+        == "SELECT COUNT(*) AS `my test` FROM `flights`"
+    )
+
+
 @pytest.mark.parametrize(
     "sql, expected",
     [
@@ -110,20 +125,20 @@ FROM "default"."flights"
             """
 SELECT
   COUNT(*)
-FROM "flights"
+FROM `flights`
 WHERE
-  "Cancelled" = TRUE
+  `Cancelled` = TRUE
             """.strip(),
         ),
         (
             'SELECT "Carrier", SUM("AvgTicketPrice") FROM "flights" GROUP BY "Carrier"',
             """
 SELECT
-  "Carrier",
-  SUM("AvgTicketPrice")
-FROM "flights"
+  `Carrier`,
+  SUM(`AvgTicketPrice`)
+FROM `flights`
 GROUP BY
-  "Carrier"
+  `Carrier`
             """.strip(),
         ),
         (
@@ -131,9 +146,9 @@ GROUP BY
             """
 SELECT
   *
-FROM "flights"
+FROM `flights`
 WHERE
-  "DestCountry" IN ('US', 'CA', 'MX')
+  `DestCountry` IN ('US', 'CA', 'MX')
             """.strip(),
         ),
     ],
@@ -165,13 +180,13 @@ GROUP BY "Carrier"
         OpenSearch().generate(expression=ast, pretty=True)
         == """
 SELECT
-  "Carrier",
+  `Carrier`,
   COUNT(*),
-  AVG("AvgTicketPrice"),
-  MAX("FlightDelayMin")
-FROM "flights"
+  AVG(`AvgTicketPrice`),
+  MAX(`FlightDelayMin`)
+FROM `flights`
 GROUP BY
-  "Carrier"
+  `Carrier`
         """.strip()
     )
 
@@ -190,10 +205,10 @@ SELECT
   *
 FROM (
   SELECT
-    "Carrier",
-    "AvgTicketPrice"
-  FROM "flights"
-) AS "sub"
+    `Carrier`,
+    `AvgTicketPrice`
+  FROM `flights`
+) AS `sub`
         """.strip()
     )
 
@@ -212,12 +227,12 @@ def test_order_by_with_quoted_identifiers() -> None:
         OpenSearch().generate(expression=ast, pretty=True)
         == """
 SELECT
-  "Carrier",
-  "AvgTicketPrice"
-FROM "flights"
+  `Carrier`,
+  `AvgTicketPrice`
+FROM `flights`
 ORDER BY
-  "AvgTicketPrice" DESC,
-  "Carrier" ASC
+  `AvgTicketPrice` DESC,
+  `Carrier` ASC
         """.strip()
     )
 
@@ -234,7 +249,7 @@ def test_limit_clause() -> None:
         == """
 SELECT
   *
-FROM "flights"
+FROM `flights`
 LIMIT 10
         """.strip()
     )