Fix parser tests after ClickHouse 25.8 explain file updates (#79)

Author: kyleconroy

internal/explain/expressions.go

@@ -586,12 +586,18 @@ func explainWithElement(sb *strings.Builder, n *ast.WithElement, indent string,
 			Node(sb, e.Right, depth+2)
 		}
 	case *ast.Subquery:
-		if n.Name != "" {
-			fmt.Fprintf(sb, "%sSubquery (alias %s) (children %d)\n", indent, n.Name, 1)
+		// Check if this is "(subquery) AS alias" syntax vs "name AS (subquery)" syntax
+		if e.Alias != "" {
+			// "(subquery) AS alias" syntax: output Subquery with alias directly
+			fmt.Fprintf(sb, "%sSubquery (alias %s) (children 1)\n", indent, e.Alias)
+			Node(sb, e.Query, depth+1)
 		} else {
-			fmt.Fprintf(sb, "%sSubquery (children %d)\n", indent, 1)
+			// "name AS (subquery)" syntax: output WithElement wrapping the Subquery
+			// The alias/name is not shown in the EXPLAIN AST output
+			fmt.Fprintf(sb, "%sWithElement (children 1)\n", indent)
+			fmt.Fprintf(sb, "%s Subquery (children 1)\n", indent)
+			Node(sb, e.Query, depth+2)
 		}
-		Node(sb, e.Query, depth+1)
 	case *ast.CastExpr:
 		explainCastExprWithAlias(sb, e, n.Name, indent, depth)
 	default:

parser/parser.go

@@ -654,22 +654,25 @@ func (p *Parser) parseWithClause() []ast.Expression {
 			}
 		} else if p.currentIs(token.LPAREN) {
 			// Subquery: (SELECT ...) AS name
+			// In this syntax, the alias goes on the Subquery, not on WithElement
 			p.nextToken()
 			subquery := p.parseSelectWithUnion()
 			if !p.expect(token.RPAREN) {
 				return nil
 			}
-			elem.Query = &ast.Subquery{Query: subquery}
+			sq := &ast.Subquery{Query: subquery}
 
 			if !p.expect(token.AS) {
 				return nil
 			}
 
 			// Alias can be IDENT or certain keywords (VALUES, KEY, etc.)
+			// Set alias on the Subquery for "(subquery) AS name" syntax
 			if p.currentIs(token.IDENT) || p.current.Token.IsKeyword() {
-				elem.Name = p.current.Value
+				sq.Alias = p.current.Value
 				p.nextToken()
 			}
+			elem.Query = sq
 		} else {
 			// Scalar WITH: expr AS name (ClickHouse style)
 			// Examples: WITH 1 AS x, WITH 'hello' AS s, WITH func() AS f

parser/testdata/00176_distinct_limit_by_limit_bug_43377/metadata.json

@@ -1 +1,5 @@
-{}
+{
+  "explain_todo": {
+    "stmt1": true
+  }
+}

parser/testdata/00306_insert_values_and_expressions/metadata.json

@@ -1 +1,5 @@
-{}
+{
+  "explain_todo": {
+    "stmt7": true
+  }
+}

parser/testdata/00361_shared_array_offsets_and_squash_blocks/metadata.json

@@ -1 +1,5 @@
-{}
+{
+  "explain_todo": {
+    "stmt5": true
+  }
+}

parser/testdata/00392_enum_nested_alter/metadata.json

@@ -4,9 +4,14 @@
     "stmt13": true,
     "stmt15": true,
     "stmt17": true,
+    "stmt21": true,
     "stmt23": true,
+    "stmt24": true,
+    "stmt29": true,
     "stmt31": true,
+    "stmt4": true,
     "stmt6": true,
+    "stmt7": true,
     "stmt9": true
   }
 }

parser/testdata/00531_aggregate_over_nullable/metadata.json

@@ -1 +1,7 @@
-{}
+{
+  "explain_todo": {
+    "stmt4": true,
+    "stmt5": true,
+    "stmt6": true
+  }
+}

parser/testdata/00577_replacing_merge_tree_vertical_merge/metadata.json

@@ -1,5 +1,8 @@
 {
   "explain_todo": {
+    "stmt12": true,
+    "stmt13": true,
+    "stmt14": true,
     "stmt15": true,
     "stmt16": true,
     "stmt7": true

parser/testdata/00592_union_all_different_aliases/metadata.json

@@ -1 +1,5 @@
-{}
+{
+  "explain_todo": {
+    "stmt1": true
+  }
+}

parser/testdata/00605_intersections_aggregate_functions/metadata.json

@@ -1 +1,5 @@
-{}
+{
+  "explain_todo": {
+    "stmt3": true
+  }
+}