#4 Count parsed octets

src/main/java/no/entra/bacnet/parseandmap/ParserResult.java

@@ -37,6 +37,11 @@ public void setNumberOfOctetsRead(int numberOfOctetsRead) {
     }
 
     public int getNumberOfOctetsRead() {
+        if (numberOfOctetsRead < 0) {
+            if (initialHexString != null && unparsedHexString != null) {
+                return (initialHexString.length() - unparsedHexString.length())/2;
+            }
+        }
         return numberOfOctetsRead;
     }
 

src/test/java/no/entra/bacnet/parseandmap/ParserResultTest.java

@@ -0,0 +1,19 @@
+package no.entra.bacnet.parseandmap;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ParserResultTest {
+
+    @Test
+    void getNumberOfOctetsRead() {
+        ParserResult parserResult = new ParserResult();
+        parserResult.setNumberOfOctetsRead(14);
+        assertEquals(14, parserResult.getNumberOfOctetsRead());
+        String initialHexString = "0c008000001e294d4e7514005549315f5a6f6e6554656d70657261747572654f291c4e750f00416e616c6f672056616c756520304f29754e915f4f29554e4441b3332c4f1f";
+        String unparsedHexString = "291c4e750f00416e616c6f672056616c756520304f29754e915f4f29554e4441b3332c4f1f";
+        parserResult = new ParserResult(null, initialHexString, unparsedHexString, true);
+        assertEquals(32, parserResult.getNumberOfOctetsRead());
+    }
+}