util: fix negative 0 check in inspect

PR-URL: #17507
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Khaidi Chu <i@2333.moe>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

Author: devsnek

lib/util.js

@@ -617,10 +617,8 @@ function formatValue(ctx, value, recurseTimes, ln) {
 }
 
 function formatNumber(fn, value) {
-  // Format -0 as '-0'. A `value === -0` check won't distinguish 0 from -0.
-  // Using a division check is currently faster than `Object.is(value, -0)`
-  // as of V8 6.1.
-  if (1 / value === -Infinity)
+  // Format -0 as '-0'. Checking `value === -0` won't distinguish 0 from -0.
+  if (Object.is(value, -0))
     return fn('-0', 'number');
   return fn(`${value}`, 'number');
 }

test/parallel/test-util-inspect.js

@@ -405,6 +405,8 @@ assert.strictEqual(
 // test positive/negative zero
 assert.strictEqual(util.inspect(0), '0');
 assert.strictEqual(util.inspect(-0), '-0');
+// edge case from check
+assert.strictEqual(util.inspect(-5e-324), '-5e-324');
 
 // test for sparse array
 {