fix: validate matcher op for __name__ in promql (#5191)

Signed-off-by: Ruihang Xia <waynestxia@gmail.com>

src/query/src/promql/planner.rs

@@ -689,6 +689,13 @@ impl PromPlanner {
             let mut matches = label_matchers.find_matchers(METRIC_NAME);
             ensure!(!matches.is_empty(), NoMetricMatcherSnafu);
             ensure!(matches.len() == 1, MultipleMetricMatchersSnafu);
+            ensure!(
+                matches[0].op == MatchOp::Equal,
+                UnsupportedMatcherOpSnafu {
+                    matcher_op: matches[0].op.to_string(),
+                    matcher: METRIC_NAME
+                }
+            );
             metric_name = matches.pop().map(|m| m.value);
         }
 

tests/cases/standalone/common/tql/basic.result

@@ -66,6 +66,10 @@ TQL EVAL (0, 10, '5s') {__name__!="test"};
 
 Error: 2000(InvalidSyntax), vector selector must contain at least one non-empty matcher
 
+TQL EVAL (0, 10, '5s') {__name__=~"test"};
+
+Error: 1004(InvalidArguments), Matcher operator =~ is not supported for __name__
+
 -- the point at 1ms will be shadowed by the point at 2ms
 TQL EVAL (0, 10, '5s') test{k="a"};
 

tests/cases/standalone/common/tql/basic.sql

@@ -22,6 +22,8 @@ TQL EVAL (0, 10, '5s') {__name__="test", __field__="i"};
 -- NOT SUPPORTED: `__name__` matcher without equal condition
 TQL EVAL (0, 10, '5s') {__name__!="test"};
 
+TQL EVAL (0, 10, '5s') {__name__=~"test"};
+
 -- the point at 1ms will be shadowed by the point at 2ms
 TQL EVAL (0, 10, '5s') test{k="a"};