chore: Add missing frontend specs (#2329)

* complete dshboard api specs

* code cleanup

* add conversation mixin spec

* add isadmin mixin spec

* add agent details component spec

* add notification badge spec

* spec for thumbnail exist in agent details

* fix the deprecation warnings

* add agent details spec

* add account selector specs

* code cleanup

* refactor contact spec

* review fixes

* review fixes

* add shared spec helper

* update api spec helper

* review fixes

app/javascript/dashboard/api/specs/inbox/message.spec.js

@@ -0,0 +1,32 @@
+import messageAPI from '../../inbox/message';
+import ApiClient from '../../ApiClient';
+import describeWithAPIMock from '../apiSpecHelper';
+
+describe('#ConversationAPI', () => {
+  it('creates correct instance', () => {
+    expect(messageAPI).toBeInstanceOf(ApiClient);
+    expect(messageAPI).toHaveProperty('get');
+    expect(messageAPI).toHaveProperty('show');
+    expect(messageAPI).toHaveProperty('create');
+    expect(messageAPI).toHaveProperty('update');
+    expect(messageAPI).toHaveProperty('delete');
+    expect(messageAPI).toHaveProperty('getPreviousMessages');
+  });
+
+  describeWithAPIMock('API calls', context => {
+    it('#getPreviousMessages', () => {
+      messageAPI.getPreviousMessages({
+        conversationId: 12,
+        before: 4573,
+      });
+      expect(context.axiosMock.get).toHaveBeenCalledWith(
+        `/api/v1/conversations/12/messages`,
+        {
+          params: {
+            before: 4573,
+          },
+        }
+      );
+    });
+  });
+});