Merge pull request #184 from ericfitz/fix/json-formatter-negative-indent

fix: Prevent negative count in SimpleJsonFormatter

Author: en-milie

src/main/java/com/endava/cats/util/SimpleJsonFormatter.java

@@ -54,7 +54,7 @@ private static String formatJsonString(String jsonStr) {
                     }
                     case '}', ']' -> {
                         if (prevChar != '{' && prevChar != '[' && prevChar != '\n') {
-                            formatted.append('\n').append(indent.repeat(indentLevel - 1));
+                            formatted.append('\n').append(indent.repeat(Math.max(0, indentLevel - 1)));
                         }
                         indentLevel--;
                         formatted.append(currentChar);

src/test/java/com/endava/cats/util/SimpleJsonFormatterTest.java

@@ -44,4 +44,27 @@ void shouldHandleEscapedQuotesInJsonString() {
         String result = SimpleJsonFormatter.formatJson(input);
         assertThat(result).isEqualTo(expected);
     }
+
+    @Test
+    void shouldHandleMalformedJsonWithExtraClosingBrackets() {
+        String input = "{\"key\":\"value\"}}";
+        String result = SimpleJsonFormatter.formatJson(input);
+        assertThat(result).isNotNull();
+    }
+
+    @Test
+    void shouldHandleMalformedJsonWithExtraClosingSquareBrackets() {
+        String input = "[1,2,3]]";
+        String result = SimpleJsonFormatter.formatJson(input);
+        assertThat(result).isNotNull();
+    }
+
+    @Test
+    void shouldHandleNestedStructures() {
+        String input = "{\"outer\":{\"inner\":{\"deep\":\"value\"}}}";
+        String result = SimpleJsonFormatter.formatJson(input);
+        assertThat(result).contains("\"outer\":");
+        assertThat(result).contains("\"inner\":");
+        assertThat(result).contains("\"deep\": \"value\"");
+    }
 }