buffer: fix comments in bidirectionalIndexOf

dcposch · silverwind · commit 39f65e665628 · 2017-01-25T00:37:50.000+01:00
PR-URL: #10162 Fixes: #9801 Reviewed-By: Roman Reiss <me@silverwind.io> Reviewed-By: Stephen Belanger <admin@stephenbelanger.com> Reviewed-By: Trevor Norris <trev.norris@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com> Reviewed-By: Rich Trott <rtrott@gmail.com>
diff --git a/lib/buffer.js b/lib/buffer.js
@@ -598,9 +598,10 @@ function bidirectionalIndexOf(buffer, val, byteOffset, encoding, dir) {
   } else if (byteOffset < -0x80000000) {
     byteOffset = -0x80000000;
   }
-  byteOffset = +byteOffset;  // Coerce to Number.
-  if (isNaN(byteOffset)) {
-    // If the offset is undefined, null, NaN, "foo", etc, search whole buffer.
+  // Coerce to Number. Values like null and [] become 0.
+  byteOffset = +byteOffset;
+  // If the offset is undefined, "foo", {}, coerces to NaN, search whole buffer.
+  if (Number.isNaN(byteOffset)) {
     byteOffset = dir ? 0 : (buffer.length - 1);
   }
   dir = !!dir;  // Cast to bool.

Original file line number	Diff line number	Diff line change
`@@ -598,9 +598,10 @@ function bidirectionalIndexOf(buffer, val, byteOffset, encoding, dir) {`
`598`	`598`	`} else if (byteOffset < -0x80000000) {`
`599`	`599`	`byteOffset = -0x80000000;`
`600`	`600`	`}`
`601`		`- byteOffset = +byteOffset; // Coerce to Number.`
`602`		`- if (isNaN(byteOffset)) {`
`603`		`- // If the offset is undefined, null, NaN, "foo", etc, search whole buffer.`
	`601`	`+ // Coerce to Number. Values like null and [] become 0.`
	`602`	`+ byteOffset = +byteOffset;`
	`603`	`+ // If the offset is undefined, "foo", {}, coerces to NaN, search whole buffer.`
	`604`	`+ if (Number.isNaN(byteOffset)) {`
`604`	`605`	`byteOffset = dir ? 0 : (buffer.length - 1);`
`605`	`606`	`}`
`606`	`607`	`dir = !!dir; // Cast to bool.`