fix: Verify supported type for Unary::Plus in sql planner

This adds a type check when planning unary plus operator. Since we
currently do not represent the operator in our logical plan we can not
check it later. Instead of introducing a new `Expr` this patch just
verifies the type during the translation instead.

datafusion/sql/src/expr/unary_op.rs

@@ -16,8 +16,11 @@
 // under the License.
 
 use crate::planner::{ContextProvider, PlannerContext, SqlToRel};
-use datafusion_common::{not_impl_err, DFSchema, Result};
-use datafusion_expr::Expr;
+use datafusion_common::{not_impl_err, plan_err, DFSchema, Result};
+use datafusion_expr::{
+    type_coercion::{is_interval, is_timestamp},
+    Expr, ExprSchemable,
+};
 use sqlparser::ast::{Expr as SQLExpr, UnaryOperator, Value};
 
 impl<'a, S: ContextProvider> SqlToRel<'a, S> {
@@ -33,7 +36,17 @@ impl<'a, S: ContextProvider> SqlToRel<'a, S> {
                 self.sql_expr_to_logical_expr(expr, schema, planner_context)?,
             ))),
             UnaryOperator::Plus => {
-                Ok(self.sql_expr_to_logical_expr(expr, schema, planner_context)?)
+                let operand =
+                    self.sql_expr_to_logical_expr(expr, schema, planner_context)?;
+                let (data_type, _) = operand.data_type_and_nullable(schema)?;
+                if data_type.is_numeric()
+                    || is_interval(&data_type)
+                    || is_timestamp(&data_type)
+                {
+                    Ok(operand)
+                } else {
+                    plan_err!("Unary operator '+' only supports numeric, interval and timestamp types")
+                }
             }
             UnaryOperator::Minus => {
                 match expr {

datafusion/sqllogictest/test_files/scalar.slt

@@ -1526,6 +1526,9 @@ NULL NULL
 query error DataFusion error: Error during planning: Negation only supports numeric, interval and timestamp types
 SELECT -'100'
 
+query error DataFusion error: Error during planning: Unary operator '\+' only supports numeric, interval and timestamp types
+SELECT +true
+
 statement ok
 drop table test_boolean