updated test coverage reporter to handle error and unknown test scenarios (#1215)

Author: aakash070

tools/celtest/test_coverage_reporter.go

@@ -96,27 +96,28 @@ func traverseAndCalculateCoverage(t *testing.T, expr ast.NavigableExpr, p Progra
 	// Check for Branch Coverage if the node is a boolean type
 	if interestingBoolNode {
 		cr.branches += 2
-		if info, found := p.CoverageStats[nodeID]; !found {
-			if logUnencountered {
-				cr.unencounteredBranches = append(cr.unencounteredBranches,
-					"\n"+preceedingTabs+fmt.Sprintf("Expression ID %d ('%s'): No coverage", nodeID, exprText))
-				preceedingTabs = preceedingTabs + "\t\t"
-			}
-		} else {
-			if _, ok := info[types.True]; ok {
+		if info, found := p.CoverageStats[nodeID]; found {
+			var trueFound, falseFound bool
+			if _, trueFound = info[types.True]; trueFound {
 				cr.coveredBooleanOutcomes++
-			} else if logUnencountered {
-				cr.unencounteredBranches = append(cr.unencounteredBranches,
-					"\n"+preceedingTabs+fmt.Sprintf("Expression ID %d ('%s'): lacks 'true' coverage", nodeID, exprText))
-				preceedingTabs = preceedingTabs + "\t\t"
-
 			}
-			if _, ok := info[types.False]; ok {
+			if _, falseFound = info[types.False]; falseFound {
 				cr.coveredBooleanOutcomes++
-			} else if logUnencountered {
-				cr.unencounteredBranches = append(cr.unencounteredBranches,
-					"\n"+preceedingTabs+fmt.Sprintf("Expression ID %d ('%s'): lacks 'false' coverage", nodeID, exprText))
-				preceedingTabs = preceedingTabs + "\t\t"
+			}
+			if logUnencountered && !(trueFound && falseFound) {
+				if falseFound {
+					cr.unencounteredBranches = append(cr.unencounteredBranches,
+						"\n"+preceedingTabs+fmt.Sprintf("Expression ID %d ('%s'): lacks 'true' coverage", nodeID, exprText))
+					preceedingTabs = preceedingTabs + "\t\t"
+				} else if trueFound {
+					cr.unencounteredBranches = append(cr.unencounteredBranches,
+						"\n"+preceedingTabs+fmt.Sprintf("Expression ID %d ('%s'): lacks 'false' coverage", nodeID, exprText))
+					preceedingTabs = preceedingTabs + "\t\t"
+				} else {
+					cr.unencounteredBranches = append(cr.unencounteredBranches,
+						"\n"+preceedingTabs+fmt.Sprintf("Expression ID %d ('%s'): No coverage", nodeID, exprText))
+					preceedingTabs = preceedingTabs + "\t\t"
+				}
 			}
 		}
 	}

tools/celtest/test_coverage_reporter_test.go

@@ -1,3 +1,18 @@
+// Copyright 2025 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package celtest provides functions for testing CEL policies and expressions.
 package celtest
 
 import (