Added

- support for web worker.
- typescript types. #10

Changed
- prevent webpack to require dependencies.

tests/worker-test.js

@@ -0,0 +1,21 @@
+(function (Worker, WORKER, SOURCE) {
+  var cases = {
+    'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855': '',
+    'd7a8fbb307d7809469ca9abcb0082e4f8d5651e46d3cdb762d02d0bf37c9e592': 'The quick brown fox jumps over the lazy dog',
+    'ef537f25c895bfa782526529a9b63d97aa631564d5d789c2b765448c8635fb6c': 'The quick brown fox jumps over the lazy dog.'
+  };
+
+  describe('#sha256', function () {
+    Object.keys(cases).forEach(function (hash) {
+      it('should be equal', function (done) {
+        var worker = new Worker(WORKER);
+        worker.onmessage = function(event) {
+          expect(event.data).to.be(hash);
+          done();
+        };
+        worker.postMessage(SOURCE);
+        worker.postMessage(cases[hash]);
+      });
+    });
+  });
+})(Worker, WORKER, SOURCE);