enhancement(search): implement non bool query compilation

services/search/pkg/opensearch/kql.go

@@ -19,6 +19,7 @@ func (k *KQL) Compile(tree *ast.Ast) (Builder, error) {
 	if err != nil {
 		return nil, err
 	}
+
 	return q, nil
 }
 
@@ -62,12 +63,27 @@ func (k *KQL) getOperatorValueAt(nodes []ast.Node, i int) string {
 	return ""
 }
 
+func (k *KQL) getBuilder(node ast.Node) (Builder, error) {
+	var builder Builder
+	switch node := node.(type) {
+	case *ast.StringNode:
+		builder = NewTermQuery[string](k.getFieldName(node.Key)).Value(node.Value)
+	case *ast.GroupNode:
+		group, err := k.compile(node.Nodes)
+		if err != nil {
+			return nil, fmt.Errorf("failed to build group: %w", err)
+		}
+		builder = group
+	}
+
+	return builder, nil
+}
+
 func (k *KQL) compile(nodes []ast.Node) (Builder, error) {
 	boolQuery := NewBoolQuery()
-
 	add := boolQuery.Must
-	for i, node := range nodes {
 
+	for i, node := range nodes {
 		prevOp := k.getOperatorValueAt(nodes, i-1)
 		nextOp := k.getOperatorValueAt(nodes, i+1)
 
@@ -78,15 +94,21 @@ func (k *KQL) compile(nodes []ast.Node) (Builder, error) {
 			add = boolQuery.Must
 		}
 
-		switch node := node.(type) {
-		case *ast.StringNode:
-			add(NewTermQuery[string](k.getFieldName(node.Key)).Value(node.Value))
-		case *ast.GroupNode:
-			group, err := k.compile(node.Nodes)
-			if err != nil {
-				return nil, fmt.Errorf("failed to build group: %w", err)
-			}
-			add(group)
+		if _, ok := node.(*ast.OperatorNode); ok {
+			// operatorNodes are not builders, so we skip them
+			continue
+		}
+
+		builder, err := k.getBuilder(node)
+		if err != nil {
+			return nil, fmt.Errorf("failed to get builder for node %T: %w", node, err)
+		}
+
+		switch {
+		case len(nodes) == 1:
+			return builder, nil
+		default:
+			add(builder)
 		}
 	}
 

services/search/pkg/opensearch/kql_test.go

@@ -19,10 +19,7 @@ func TestKQL_Compile(t *testing.T) {
 					&ast.StringNode{Value: "moby di*"},
 				},
 			},
-			want: opensearch.NewBoolQuery().
-				Must(
-					opensearch.NewTermQuery[string]("Name").Value("moby di*"),
-				),
+			want: opensearch.NewTermQuery[string]("Name").Value("moby di*"),
 		},
 		{
 			name: "remaps known field names",
@@ -31,12 +28,18 @@ func TestKQL_Compile(t *testing.T) {
 					&ast.StringNode{Key: "mediatype", Value: "application/gzip"},
 				},
 			},
-			want: opensearch.NewBoolQuery().
-				Must(
-					opensearch.NewTermQuery[string]("MimeType").Value("application/gzip"),
-				),
+			want: opensearch.NewTermQuery[string]("MimeType").Value("application/gzip"),
 		},
 		// kql to os dsl - type tests
+		{
+			name: "remaps known field names",
+			got: &ast.Ast{
+				Nodes: []ast.Node{
+					&ast.StringNode{Key: "a", Value: "a"},
+				},
+			},
+			want: opensearch.NewTermQuery[string]("a").Value("a"),
+		},
 		// kql to os dsl - structure tests
 		{
 			name: "[*]",
@@ -45,10 +48,7 @@ func TestKQL_Compile(t *testing.T) {
 					&ast.StringNode{Key: "name", Value: "moby di*"},
 				},
 			},
-			want: opensearch.NewBoolQuery().
-				Must(
-					opensearch.NewTermQuery[string]("Name").Value("moby di*"),
-				),
+			want: opensearch.NewTermQuery[string]("Name").Value("moby di*"),
 		},
 		{
 			name: "[* *]",