fix NOT operator in CEL filtering

- NOT is correctly added to unary operators
- remove negate, it is not required/useful in non numeric filters/expressions
- added unit tests for NOT operator
- fixes tektoncd#498

Signed-off-by: Avinal Kumar <avinal@redhat.com>

pkg/api/server/cel2sql/convert_test.go

@@ -74,6 +74,16 @@ func TestConvertRecordExpressions(t *testing.T) {
 			in:   `data.metadata.name.contains("foo")`,
 			want: "POSITION('foo' IN (data->'metadata'->>'name')) <> 0",
 		},
+		{
+			name: "not contains string function",
+			in:   `!(data.metadata.annotations.contains("foo"))`,
+			want: "NOT POSITION('foo' IN (data->'metadata'->>'annotations')) <> 0",
+		},
+		{
+			name: "complex not expressions",
+			in:   `!(data.metadata.annotations.contains("foo")) && data.metadata.name.endsWith("bar")`,
+			want: "NOT POSITION('foo' IN (data->'metadata'->>'annotations')) <> 0 AND (data->'metadata'->>'name') LIKE '%' || 'bar'",
+		},
 		{
 			name: "endsWith string function",
 			in:   `data.metadata.name.endsWith("bar")`,
@@ -226,6 +236,11 @@ func TestConvertResultExpressions(t *testing.T) {
 			in:   `summary.annotations["branch"] == "main"`,
 			want: `recordsummary_annotations @> '{"branch":"main"}'::jsonb`,
 		},
+		{
+			name: "not Result.Summary.Annotations",
+			in:   `!(summary.annotations["branch"] == "main")`,
+			want: `NOT recordsummary_annotations @> '{"branch":"main"}'::jsonb`,
+		},
 		{
 			name: "Result.Summary.Annotations",
 			in:   `"main" == summary.annotations["branch"]`,

pkg/api/server/cel2sql/interpreter.go

@@ -293,7 +293,6 @@ func (i *interpreter) interpretUnaryCallExpr(expr *exprpb.Expr_Call) error {
 	if err := i.interpretExpr(expr.Args[0]); err != nil {
 		return err
 	}
-	i.query.WriteString(space)
 	return nil
 }
 

pkg/api/server/cel2sql/operators.go

@@ -20,13 +20,12 @@ import (
 
 var (
 	unaryOperators = map[string]string{
-		operators.Negate: "NOT",
+		operators.LogicalNot: "NOT",
 	}
 
 	binaryOperators = map[string]string{
 		operators.LogicalAnd:    "AND",
 		operators.LogicalOr:     "OR",
-		operators.LogicalNot:    "NOT",
 		operators.Equals:        "=",
 		operators.NotEquals:     "<>",
 		operators.Less:          "<",