chore: added extra tests and conditions

Author: 0PrashantYadav0

lib/node_modules/@stdlib/stats/base/dists/binomial/variance/manifest.json

@@ -39,7 +39,8 @@
       "libpath": [],
       "dependencies": [
         "@stdlib/math/base/napi/binary",
-        "@stdlib/math/base/assert/is-nan"
+        "@stdlib/math/base/assert/is-nan",
+        "@stdlib/math/base/assert/is-nonnegative-integer"
       ]
     },
     {
@@ -54,7 +55,8 @@
       "libraries": [],
       "libpath": [],
       "dependencies": [
-        "@stdlib/math/base/assert/is-nan"
+        "@stdlib/math/base/assert/is-nan",
+        "@stdlib/math/base/assert/is-nonnegative-integer"
       ]
     },
     {
@@ -69,7 +71,8 @@
       "libraries": [],
       "libpath": [],
       "dependencies": [
-        "@stdlib/math/base/assert/is-nan"
+        "@stdlib/math/base/assert/is-nan",
+        "@stdlib/math/base/assert/is-nonnegative-integer"
       ]
     }
   ]

lib/node_modules/@stdlib/stats/base/dists/binomial/variance/src/main.c

@@ -18,6 +18,7 @@
 
 #include "stdlib/stats/base/dists/binomial/variance.h"
 #include "stdlib/math/base/assert/is_nan.h"
+#include "stdlib/math/base/assert/is_nonnegative_integer.h"
 
 /**
 * Returns the variance of a binomial distribution.
@@ -36,7 +37,8 @@ double stdlib_base_dists_binomial_variance( const double n, const double p ) {
 		stdlib_base_is_nan( p ) ||
 		n < 0.0 ||
 		p < 0.0 ||
-		p > 1.0
+		p > 1.0 ||
+		!stdlib_base_is_nonnegative_integer( n )
 	) {
 		return 0.0 / 0.0;
 	}

lib/node_modules/@stdlib/stats/base/dists/binomial/variance/test/test.native.js

@@ -59,14 +59,20 @@ tape( 'if provided `NaN` for any parameter, the function returns `NaN`', opts, f
 	t.end();
 });
 
-tape( 'if provided `n < 0`, the function returns `NaN`', opts, function test( t ) {
-	var y;
+tape( 'if provided an `n` which is not a nonnegative integer, the function returns `NaN`', function test( t ) {
+	var v;
 
-	y = variance( -1, 0.5 );
-	t.equal( isnan( y ), true, 'returns NaN' );
+	v = variance( 1.5, 0.5 );
+	t.equal( isnan( v ), true, 'returns NaN' );
 
-	y = variance( NaN, 0.5 );
-	t.equal( isnan( y ), true, 'returns NaN' );
+	v = variance( -2, 0.5 );
+	t.equal( isnan( v ), true, 'returns NaN' );
+
+	v = variance( -1, 0.5 );
+	t.equal( isnan( v ), true, 'returns NaN' );
+
+	v = variance( 2.5, 0.5 );
+	t.equal( isnan( v ), true, 'returns NaN' );
 
 	t.end();
 });