Merge pull request #552 from Chalarangelo/hash

[FEATURE] Hash methods

snippets/hashBrowser.md

@@ -0,0 +1,22 @@
+### hashBrowser
+
+Creates a hash for a value using the [SHA-256](https://en.wikipedia.org/wiki/SHA-2) algorithm. Returns a promise.
+
+Use the [SubtleCrypto](https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto) API to create a hash for the given value.
+
+```js
+const hashBrowser = val =>
+  crypto.subtle
+    .digest('SHA-256', new TextEncoder('utf-8').encode(val))
+    .then(h => {
+      let hexes = [],
+        view = new DataView(h);
+      for (let i = 0; i < view.byteLength; i += 4)
+        hexes.push(('00000000' + view.getUint32(i).toString(16)).slice(-8));
+      return hexes.join('');
+    });
+```
+
+```js
+hashBrowser(JSON.stringify({a :'a', b: [1,2,3,4], 'foo': {c: 'bar'}})).then(console.log); // '04aa106279f5977f59f9067fa9712afc4aedc6f5862a8defc34552d8c7206393'
+```

snippets/hashNode.md

@@ -0,0 +1,15 @@
+### hashNode
+
+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.
+
+```js
+const crypto = require('crypto');
+const hashNode = val =>
+  new Promise(resolve => setTimeout(() => resolve(crypto.createHash('sha256').update(val).digest('hex')),0));
+```
+
+```js
+hashBrowser(JSON.stringify({a :'a', b: [1,2,3,4], 'foo': {c: 'bar'}})).then(console.log); // '04aa106279f5977f59f9067fa9712afc4aedc6f5862a8defc34552d8c7206393'
+```