Update hashNode

snippets/hashNode.md

@@ -1,11 +1,14 @@
 ---
 title: hashNode
-tags: node,promise,intermediate
+tags: node,promise,advanced
 ---
 
-Creates a hash for a value using the [SHA-256](https://en.wikipedia.org/wiki/SHA-2) algorithm. Returns a promise.
+Creates a hash for a value using the [SHA-256](https://en.wikipedia.org/wiki/SHA-2) algorithm.
+Returns a promise.
 
-- Use `crypto` API to create a hash for the given value, `setTimeout` to prevent blocking on a long operation, and a `Promise` to give it a familiar interface.
+- Use `crypto.createHash()` to create a `Hash` object with the appropriate algorithm.
+- Use `hash.update()` to add the data from `val` to the `Hash`, `hash.digest()` to calculate the digest of the data.
+- Use `setTimeout()` to prevent blocking on a long operation, and return a `Promise` to give it a familiar interface.
 
 ```js
 const crypto = require('crypto');
@@ -13,18 +16,15 @@ const crypto = require('crypto');
 const hashNode = val =>
   new Promise(resolve =>
     setTimeout(
-      () =>
+      () => resolve(crypto.createHash('sha256').update(val).digest('hex')),
-        resolve(
-          crypto
-            .createHash('sha256')
-            .update(val)
-            .digest('hex')
-        ),
       0
     )
   );
 ```
 
 ```js
-hashNode(JSON.stringify({ a: 'a', b: [1, 2, 3, 4], foo: { c: 'bar' } })).then(console.log); // '04aa106279f5977f59f9067fa9712afc4aedc6f5862a8defc34552d8c7206393'
+hashNode(JSON.stringify({ a: 'a', b: [1, 2, 3, 4], foo: { c: 'bar' } })).then(
+  console.log
+);
+// '04aa106279f5977f59f9067fa9712afc4aedc6f5862a8defc34552d8c7206393'
 ```