improve coverage

test/accounts.js

@@ -81,6 +81,13 @@ describe('Account', function () {
       })
   });
 
+  it('should throw error for update subAccount via interface', function () {
+    return client.subAccounts.update()
+        .catch(function(errorResponse) {
+        assert.equal(errorResponse, 'Error: Missing mandatory field: id')
+      })
+  });
+
   it('list subAccounts', function () {
     return client.subAccounts.list()
       .then(function(accounts) {
@@ -94,4 +101,11 @@ describe('Account', function () {
         assert.equal(accounts, true)
       })
   });
+
+  it('Should throw error for delete subAccounts via interface', function () {
+    return client.subAccounts.delete()
+     .catch(function(errorResponse) {
+      assert.equal(errorResponse, 'Error: Missing mandatory field: id')
+    })
+  });
 });

test/media.js

@@ -11,16 +11,32 @@ let client = new Client('sampleid', 'sammpletoken', 'sampleproxy');
 
 describe('MediaInterface', function () {
 
-  it('list media  via interface', function () {
+  it('list media via interface', function () {
     return client.media.list()
     .then(function (res) {
       assert.notEqual(res.length, 0)
       })
   });
+
+  it(' should throw error for list media via interface', function () {
+    return client.media.list('id')
+    .catch(function(errorResponse) {
+      assert.equal(errorResponse, 'ReferenceError: id is not defined')
+    })
+  });
+
   it('should get media', function () {
     return client.media.get('0178eb8a-461a-4fd1-bc37-13eebfdc0676')
       .then(function (res) {
         assert.equal(res.mediaId, '0178eb8a-461a-4fd1-bc37-13eebfdc0676')
       })
   });
+
+  it('should throw error for get media', function () {
+    return client.media.get()
+    .catch(function(errorResponse) {
+      assert.equal(errorResponse, 'Error: Missing mandatory field: media_id')
+    })
+  });
+
 });