tests: internal: fuzzers: cmetrics_fuzzer: extend

Extend cmetrics_fuzzer so it reaches prometheus decoding logic as well.

Signed-off-by: David Korczynski <[email protected]>

Author: DavidKorczynski

tests/internal/fuzzers/cmetrics_decode_fuzz.c

@@ -18,6 +18,7 @@
  */
 
 #include <cmetrics/cmt_decode_opentelemetry.h>
+#include <cmetrics/cmt_decode_prometheus.h>
 
 
 int
@@ -34,7 +35,7 @@ LLVMFuzzerTestOneInput(const uint8_t * data, size_t size)
         return 0;
     }
 
-    decider = data[0] % 2;
+    decider = data[0] % 3;
 
     /* Adjust data pointer since the first byte is used */
     data += 1;
@@ -54,5 +55,15 @@ LLVMFuzzerTestOneInput(const uint8_t * data, size_t size)
             cmt_destroy(cmt);
         }
     }
+    else if (decider == 2) {
+        if (size == 0) {
+            return 0;
+        }
+        struct cmt_decode_prometheus_parse_opts opts;
+        result = cmt_decode_prometheus_create(&cmt, data, size, &opts);
+        if (result == CMT_DECODE_PROMETHEUS_SUCCESS) {
+            cmt_decode_prometheus_destroy(cmt);
+        }
+    }
     return 0;
 }