Implement $nor (#13)

See: https://www.mongodb.com/docs/manual/reference/operator/query/nor/

Author: erikdubbelboer

filter/converter.go

@@ -93,7 +93,7 @@ func (c *Converter) convertFilter(filter map[string]any, paramIndex int) (string
 		value := filter[key]
 
 		switch key {
-		case "$or", "$and":
+		case "$or", "$and", "$nor":
 			opConditions, ok := anyToSliceMapAny(value)
 			if !ok {
 				return "", nil, fmt.Errorf("invalid value for $or operator (must be array of objects): %v", value)
@@ -112,14 +112,18 @@ func (c *Converter) convertFilter(filter map[string]any, paramIndex int) (string
 				inner = append(inner, innerConditions)
 				values = append(values, innerValues...)
 			}
-			op := "AND"
-			if key == "$or" {
-				op = "OR"
-			}
-			if len(inner) > 1 {
-				conditions = append(conditions, "("+strings.Join(inner, " "+op+" ")+")")
+			if key == "$nor" {
+				conditions = append(conditions, "NOT ("+strings.Join(inner, " OR ")+")")
 			} else {
-				conditions = append(conditions, strings.Join(inner, " "+op+" "))
+				op := "AND"
+				if key == "$or" {
+					op = "OR"
+				}
+				if len(inner) > 1 {
+					conditions = append(conditions, "("+strings.Join(inner, " "+op+" ")+")")
+				} else {
+					conditions = append(conditions, strings.Join(inner, " "+op+" "))
+				}
 			}
 		default:
 			if !isValidPostgresIdentifier(key) {

filter/converter_test.go

@@ -137,6 +137,14 @@ func TestConverter_Convert(t *testing.T) {
 			nil,
 			fmt.Errorf("$or as scalar operator not supported"),
 		},
+		{
+			"$nor operator basic",
+			nil,
+			`{"$nor": [{"name": "John"}, {"name": "Doe"}]}`,
+			`NOT (("name" = $1) OR ("name" = $2))`,
+			[]any{"John", "Doe"},
+			nil,
+		},
 		{
 			"and operator basic",
 			nil,

fuzz/fuzz_test.go

@@ -27,6 +27,7 @@ func FuzzConverter(f *testing.F) {
 		`{"$or": [{"org": "poki", "admin": true}, {"age": {"$gte": 18}}]}`,
 		`{"$or": [{"$or": [{"name": "John"}, {"name": "Doe"}]}, {"name": "Jane"}]}`,
 		`{"foo": { "$or": [ "bar", "baz" ] }}`,
+		`{"$nor": [{"name": "John"}, {"name": "Doe"}]}`,
 		`{"$and": [{"name": "John"}, {"version": 3}]}`,
 		`{"$and": [{"name": "John", "version": 3}]}`,
 		`{"name": {"$regex": "John"}}`,

integration/postgres_test.go

@@ -303,6 +303,12 @@ func TestIntegration_BasicOperators(t *testing.T) {
 			[]int{7, 8, 9, 10},
 			nil,
 		},
+		{
+			"$nor",
+			`{"$nor": [{"name": "Alice"}, {"name": "Bob"}]}`,
+			[]int{3, 4, 5, 6, 7, 8, 9, 10},
+			nil,
+		},
 	}
 
 	for _, tt := range tests {