fix(panic): fix panic when censoring utf-8

goaway.go

@@ -143,62 +143,63 @@ func (g *ProfanityDetector) indexToRune(s string, index int) int {
 	count := 0
 	for i := range s {
 		if i == index {
-			return count
+			break
+		}
+		if i < index {
+			count++
 		}
-		count++
 	}
-	return -1
+	return count
 }
 
 // Censor takes in a string (word or sentence) and tries to censor all profanities found.
 func (g *ProfanityDetector) Censor(s string) string {
 	censored := []rune(s)
 	var originalIndexes []int
 	s, originalIndexes = g.sanitize(s, true)
-	// Check for false negatives
-	for _, word := range g.falseNegatives {
-		currentIndex := 0
-		for currentIndex != -1 {
-			if foundIndex := strings.Index(s[currentIndex:], word); foundIndex != -1 {
-				for i := 0; i < len([]rune(word)); i++ {
-					runeIndex := g.indexToRune(string(censored), currentIndex+foundIndex+i)
-					censored[originalIndexes[runeIndex]] = '*'
+	runeWordLength := 0
+
+	checkProfanity := func(wordList []string) {
+		for _, word := range wordList {
+			currentIndex := 0
+			runeWordLength = len([]rune(word))
+			for currentIndex != -1 {
+				if foundIndex := strings.Index(s[currentIndex:], word); foundIndex != -1 {
+					for i := 0; i < runeWordLength; i++ {
+						runeIndex := g.indexToRune(s, currentIndex+foundIndex) + i
+						if runeIndex < len(originalIndexes) {
+							censored[originalIndexes[runeIndex]] = '*'
+						}
+					}
+					currentIndex += foundIndex + len([]byte(word))
+				} else {
+					break
 				}
-				currentIndex += foundIndex + len([]rune(word))
-			} else {
-				break
-			}
-		}
-	}
-	// Remove false positives
-	for _, word := range g.falsePositives {
-		currentIndex := 0
-		for currentIndex != -1 {
-			if foundIndex := strings.Index(s[currentIndex:], word); foundIndex != -1 {
-				foundRuneIndex := g.indexToRune(s, foundIndex)
-				originalIndexes = append(originalIndexes[:foundRuneIndex], originalIndexes[foundRuneIndex+len(word):]...)
-				currentIndex += foundIndex + len([]rune(word))
-			} else {
-				break
 			}
 		}
-		s = strings.Replace(s, word, "", -1)
 	}
-	// Check for profanities
-	for _, word := range g.profanities {
-		currentIndex := 0
-		for currentIndex != -1 {
-			if foundIndex := strings.Index(s[currentIndex:], word); foundIndex != -1 {
-				for i := 0; i < len([]rune(word)); i++ {
-					runeIndex := g.indexToRune(string(censored), currentIndex+foundIndex+i)
-					censored[originalIndexes[runeIndex]] = '*'
+
+	removeFalsePositives := func() {
+		for _, word := range g.falsePositives {
+			currentIndex := 0
+			runeWordLength = len([]rune(word))
+			for currentIndex != -1 {
+				if foundIndex := strings.Index(s[currentIndex:], word); foundIndex != -1 {
+					foundRuneIndex := g.indexToRune(s, foundIndex)
+					originalIndexes = append(originalIndexes[:foundRuneIndex], originalIndexes[foundRuneIndex+runeWordLength:]...)
+					currentIndex += foundIndex + len([]byte(word))
+				} else {
+					break
 				}
-				currentIndex += foundIndex + len([]rune(word))
-			} else {
-				break
 			}
+			s = strings.Replace(s, word, "", -1)
 		}
 	}
+
+	checkProfanity(g.falseNegatives)
+	removeFalsePositives()
+	checkProfanity(g.profanities)
+
 	return string(censored)
 }
 

goaway_test.go

@@ -655,3 +655,24 @@ func TestSanitizeWithoutSanitizingLeetSpeak(t *testing.T) {
 		t.Errorf("Expected '%s', got '%s'", expectedString, sanitizedString)
 	}
 }
+
+func TestDefaultDriver_UTF8(t *testing.T) {
+	detector := NewProfanityDetector().WithCustomDictionary(
+		[]string{"anal", "あほ"}, // profanities
+		[]string{"あほほ"},        // falsePositives
+		[]string{"あほほし"},       // falseNegatives
+	)
+
+	unsanitizedString := "いい加減にしろ あほほし あほほ あほ anal ほ"
+	expectedString := "いい加減にしろ **** あほほ ** **** ほ"
+
+	isProfane := detector.IsProfane(unsanitizedString)
+	if !isProfane {
+		t.Error("Expected false, got false from sentence", unsanitizedString)
+	}
+
+	sanitizedString := detector.Censor(unsanitizedString)
+	if sanitizedString != expectedString {
+		t.Errorf("Expected '%s', got '%s'", expectedString, sanitizedString)
+	}
+}