feat: support single element array in "IN" (#12)

* Fix single element "in" clauses * Guard against invalid slice access * Always return a slice --------- Co-authored-by: Daniel Richter <[email protected]>
casbin · Dec 28, 2024 · 31caa3f · 31caa3f
1 parent 00136f1
commit 31caa3f
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Showing 3 changed files with 26 additions and 0 deletions.
diff --git a/evaluationStage.go b/evaluationStage.go
@@ -429,6 +429,16 @@ func makeAccessorStage(pair []string) evaluationOperator {
 	}
 }
 
+func ensureSliceStage(op evaluationOperator) evaluationOperator {
+	return func(left interface{}, right interface{}, parameters Parameters) (interface{}, error) {
+		orig, err := op(left, right, parameters)
+		if err != nil {
+			return orig, err
+		}
+		return []interface{}{orig}, nil
+	}
+}
+
 func separatorStage(left interface{}, right interface{}, parameters Parameters) (interface{}, error) {
 
 	var ret []interface{}

diff --git a/evaluation_test.go b/evaluation_test.go
@@ -505,6 +505,12 @@ func TestNoParameterEvaluation(test *testing.T) {
 			Input:    "!(1 in (1, 2, 3))",
 			Expected: false,
 		},
+		EvaluationTest{
+
+			Name:     "Single Element Array membership literal",
+			Input:    "1 in (1)",
+			Expected: true,
+		},
 		EvaluationTest{
 
 			Name:     "Logical operator reordering (#30)",

diff --git a/stagePlanner.go b/stagePlanner.go
@@ -389,12 +389,22 @@ func planValue(stream *tokenStream) (*evaluationStage, error) {
 	switch token.Kind {
 
 	case CLAUSE:
+		var prev ExpressionToken
+		if stream.index > 1 {
+			prev = stream.tokens[stream.index-2]
+		}
 
 		ret, err = planTokens(stream)
 		if err != nil {
 			return nil, err
 		}
 
+		// clauses with single elements don't trigger SEPARATE stage planner
+		// this ensures that when used as part of an "in" comparison, the array requirement passes
+		if prev.Kind == COMPARATOR && prev.Value == "in" && ret.symbol == LITERAL {
+			ret.operator = ensureSliceStage(ret.operator)
+		}
+
 		// advance past the CLAUSE_CLOSE token. We know that it's a CLAUSE_CLOSE, because at parse-time we check for unbalanced parens.
 		stream.next()