Fix exception `java.lang.StringIndexOutOfBoundsException: String inde…

…x out of range: -1` (#12)
d10xa · Nov 5, 2024 · ab67a5a · ab67a5a
1 parent cce5e26
commit ab67a5a
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Showing 2 changed files with 21 additions and 7 deletions.
diff --git a/json-log-viewer/shared/src/main/scala/ru/d10xa/jsonlogviewer/JsonDetector.scala b/json-log-viewer/shared/src/main/scala/ru/d10xa/jsonlogviewer/JsonDetector.scala
@@ -7,14 +7,18 @@ class JsonDetector {
     @tailrec
     def loop(i: Int, start: Int, end: Int): (Int, Int) =
       val ri = s.length - i - 1
-      val rchar = s.charAt(ri)
-      val lchar = s.charAt(i)
-      val nextEnd = if(end == -1 && rchar == '}') ri else end
-      val nextStart = if(start == -1 && lchar == '{') i else start
-      if (s.length/2<i || (nextStart != -1 && nextEnd != -1)) {
-        (nextStart, nextEnd)
+      if (ri < 0) {
+        (-1, -1)
       } else {
-        loop(i + 1, nextStart, nextEnd)
+        val rchar = s.charAt(ri)
+        val lchar = s.charAt(i)
+        val nextEnd = if (end == -1 && rchar == '}') ri else end
+        val nextStart = if (start == -1 && lchar == '{') i else start
+        if (s.length / 2 < i || (nextStart != -1 && nextEnd != -1)) {
+          (nextStart, nextEnd)
+        } else {
+          loop(i + 1, nextStart, nextEnd)
+        }
       }
     val res = loop(0, -1, -1)
     res match

diff --git a/json-log-viewer/shared/src/test/scala/ru/d10xa/jsonlogviewer/JsonPrefixPostfixTest.scala b/json-log-viewer/shared/src/test/scala/ru/d10xa/jsonlogviewer/JsonPrefixPostfixTest.scala
@@ -17,4 +17,14 @@ class JsonPrefixPostfixTest extends munit.FunSuite {
     assertEquals(postfixOpt, None)
   }
 
+  test(
+    "detectJson should throw StringIndexOutOfBoundsException when jsonDetector returns invalid indices"
+  ) {
+    val jsonDetector = new JsonDetector()
+    val jsonPrefixPostfix = new JsonPrefixPostfix(jsonDetector)
+    val input = "{"
+    val result = jsonPrefixPostfix.detectJson(input)
+    assertEquals(result, (input, None, None))
+  }
+
 }