fix(tql): avoid unwrap on parsing tql query (#4502)

* fix(tql): avoid unwrap on parsing tql query

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

* add unit test

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

---------

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

src/sql/src/parsers/error.rs

@@ -31,4 +31,12 @@ pub enum TQLError {
 
     #[snafu(display("Failed to evaluate TQL expression: {}", msg))]
     Evaluation { msg: String },
+
+    #[snafu(display("Failed to convert TQL expression to logical expression"))]
+    ConvertToLogicalExpression {
+        #[snafu(source)]
+        error: Box<crate::error::Error>,
+        #[snafu(implicit)]
+        location: Location,
+    },
 }

src/sql/src/parsers/tql_parser.rs

@@ -31,6 +31,7 @@ const VERBOSE: &str = "VERBOSE";
 
 use sqlparser::parser::Parser;
 
+use super::error::ConvertToLogicalExpressionSnafu;
 use crate::dialect::GreptimeDbDialect;
 use crate::parsers::error::{EvaluationSnafu, ParserSnafu, TQLError};
 
@@ -182,7 +183,9 @@ impl<'a> ParserContext<'a> {
 
     fn parse_tokens(tokens: Vec<Token>) -> std::result::Result<String, TQLError> {
         let parser_expr = Self::parse_to_expr(tokens)?;
-        let lit = utils::parser_expr_to_scalar_value(parser_expr).unwrap();
+        let lit = utils::parser_expr_to_scalar_value(parser_expr)
+            .map_err(Box::new)
+            .context(ConvertToLogicalExpressionSnafu)?;
 
         let second = match lit {
             ScalarValue::TimestampNanosecond(ts_nanos, _)
@@ -270,6 +273,11 @@ mod tests {
             }
             _ => unreachable!(),
         }
+
+        let sql = "TQL EVAL (now(), now()-'5m', '30s') http_requests_total";
+        let result =
+            ParserContext::create_with_dialect(sql, &GreptimeDbDialect {}, ParseOptions::default());
+        assert!(result.is_err());
     }
 
     #[test]