Add API call to get a user by their email address (#4884)

* Add API call to get a user by their email address

* update per review

webapp/client/client.jsx

@@ -974,6 +974,15 @@ export default class Client {
             end(this.handleResponse.bind(this, 'getByUsername', success, error));
     }
 
+    getByEmail(email, success, error) {
+        request.
+            get(`${this.getUsersRoute()}/email/${email}`).
+            set(this.defaultHeaders).
+            type('application/json').
+            accept('application/json').
+            end(this.handleResponse.bind(this, 'getByEmail', success, error));
+    }
+
     login(loginId, password, mfaToken, success, error) {
         this.doLogin({login_id: loginId, password, token: mfaToken}, success, error);
 

webapp/tests/client_user.test.jsx

@@ -51,6 +51,21 @@ describe('Client.User', function() {
         });
     });
 
+    it('getByEmail', function(done) {
+        TestHelper.initBasic(() => {
+            TestHelper.basicClient().getByEmail(
+                TestHelper.basicUser().email,
+                function(data) {
+                    assert.equal(data.email, TestHelper.basicUser().email);
+                    done();
+                },
+                function(err) {
+                    done(new Error(err.message));
+                }
+            );
+        });
+    });
+
     it('getInitialLoad', function(done) {
         TestHelper.initBasic(() => {
             TestHelper.basicClient().getInitialLoad(