1 files changed, 13 insertions, 1 deletions
diff --git a/test/hurst_exponent.c b/test/hurst_exponent.c
index ccf54c8..a200de9 100644
--- a/test/hurst_exponent.c
+++ b/test/hurst_exponent.c
@@ -1,3 +1,4 @@
+#include <math.h>
 #include <stddef.h>
 #include "ts.h"
 
@@ -6,6 +7,17 @@ bool ts_test_hurst_exponent( void )
 	uint_t const c[] = { 5 };
 	fp_t const x0[] = { 1,2,3,4,5,6,7,8,9,10 };
 	fp_t e0[10];
-	ts_hurst_exponent((fp_t*[]){e0}, 1, (fp_t const *[]){x0}, 1, 10, (ts_constant_t *)&c);
+	int ret = ts_hurst_exponent((fp_t*[]){e0}, 1, (fp_t const *[]){x0}, 1, 10, (ts_constant_t *)&c);
+	if ( ret != 0 )
+		return false;
+
+	/* Verify output is finite (no NaN/Inf for valid input) */
+	for ( uint_t i = 0; i < 10; ++i )
+	{
+		fp_t v = e0[i];
+		if ( v != v ) return false;
+		if ( v == (fp_t)INFINITY || v == (fp_t)-INFINITY ) return false;
+	}
+
 	return true;
 }