Fixes #106:

  Checking parenthesis for subExpression during outputExpression leads to
  only counting the subExpression parenthesis as the final tally, and
  causes correct parenthesis cases to be incorrect as the prev counts are lost

filterExprParser.go

@@ -102,14 +102,9 @@ func (fe *FilterExpression) String() string {
  return strings.Join(output, " ")
 }
 
-// Outputs the head of the Expression match tree of which represents everything underneath
-func (f *FilterExpression) OutputExpression() (Expression, error) {
+func (f *FilterExpression) outputExpressionNoParenCheck() (Expression, error) {
  var outExpr OrExpr
 
- if f.GetTotalOpenParens() != f.GetTotalCloseParens() {
- return outExpr, ErrorMalformedParenthesis
- }
-
  for _, oneExpr := range f.AndConditions {
  andExpr, err := oneExpr.OutputExpression()
  if err != nil {
@@ -123,7 +118,7 @@ func (f *FilterExpression) OutputExpression() (Expression, error) {
  combinedExpr = append(combinedExpr, outExpr)
 
  for _, subFilterExpr := range f.SubFilterExpr {
- subExpr, err := subFilterExpr.OutputExpression()
+ subExpr, err := subFilterExpr.outputExpressionNoParenCheck()
  if err != nil {
  return combinedExpr, err
  }
@@ -136,6 +131,15 @@ func (f *FilterExpression) OutputExpression() (Expression, error) {
  }
 }
 
+// Outputs the head of the Expression match tree of which represents everything underneath
+func (f *FilterExpression) OutputExpression() (Expression, error) {
+ if f.GetTotalOpenParens() != f.GetTotalCloseParens() {
+ return nil, ErrorMalformedParenthesis
+ }
+
+ return f.outputExpressionNoParenCheck()
+}
+
 type FEOpenParen struct {
  Parens string `@"("`
 }

filterExprParser_test.go

@@ -117,6 +117,12 @@ func TestFilterExpressionParser(t *testing.T) {
  expr, err = fe.OutputExpression()
  assert.Nil(err)
 
+ fe = &FilterExpression{}
+ err = parser.ParseString("((TRUE OR FALSE) AND (FALSE OR TRUE)) OR (TRUE AND TRUE)", fe)
+ assert.Nil(err)
+ expr, err = fe.OutputExpression()
+ assert.Nil(err)
+
  fe = &FilterExpression{}
  err = parser.ParseString("NOT NOT NOT TRUE", fe)
  assert.Nil(err)
@@ -745,7 +751,7 @@ func TestFilterExpressionParser(t *testing.T) {
  _, err = fe.OutputExpression()
  assert.NotNil(err)
 
- // For invalid date values, it will always return -1
+ // For invalid date values, it will be nil and should be smaller than any other valids
  fe = &FilterExpression{}
  err = parser.ParseString("DATE(fieldpath.path) < DATE(\"2019-01-01\")", fe)
  expr, err = fe.OutputExpression()
@@ -761,4 +767,9 @@ func TestFilterExpressionParser(t *testing.T) {
  udMarsh, _ = json.Marshal(userData)
  match, err = m.Match(udMarsh)
  assert.True(match)
+
+ // Invalid parenthesis
+ _, fe, err = NewFilterExpressionParser("((TRUE OR FALSE () AND TRUE))")
+ _, err = fe.OutputExpression()
+ assert.NotNil(err)
 }