test: add NaN tests

Signed-off-by: Athan <[email protected]>

Author: kgryte

lib/node_modules/@stdlib/lapack/base/dlapy2/test/test.js

@@ -27,6 +27,7 @@ var abs = require( '@stdlib/math/base/special/abs' );
 var sqrt = require( '@stdlib/math/base/special/sqrt' );
 var pow = require( '@stdlib/math/base/special/pow' );
 var isPositiveZero = require( '@stdlib/math/base/assert/is-positive-zero' );
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
 var dlapy2 = require( './../lib' );
 
 
@@ -61,6 +62,21 @@ tape( 'the function returns `+0` if both arguments are `+-0`', function test( t
 	t.end();
 });
 
+tape( 'the function returns `NaN` if either argument is `NaN`', function test( t ) {
+	var h;
+
+	h = dlapy2( NaN, 0.0 );
+	t.strictEqual( isnan( h ), true, 'returns expected value' );
+
+	h = dlapy2( 0.0, NaN );
+	t.strictEqual( isnan( h ), true, 'returns expected value' );
+
+	h = dlapy2( NaN, NaN );
+	t.strictEqual( isnan( h ), true, 'returns expected value' );
+
+	t.end();
+});
+
 tape( 'the function computes the hypotenuse', function test( t ) {
 	var expected;
 	var delta;