[Enhancement] Fetch previous messages in the conversation (#355)

* Fetch previous messages in the conversation

* Add specs for conversation store

* Fix codeclimate issues

* Exclude specs folder

* Exclude globally

* Fix path in exclude patterns

* Add endPoints spec

* Add snapshots for Spinner

* Add specs for actions

app/javascript/widget/store/modules/specs/conversation/mutations.spec.js

@@ -0,0 +1,95 @@
+import { mutations } from '../../conversation';
+
+const temporaryMessagePayload = {
+  content: 'hello',
+  id: 1,
+  message_type: 0,
+  status: 'in_progress',
+};
+
+const incomingMessagePayload = {
+  content: 'hello',
+  id: 1,
+  message_type: 0,
+  status: 'sent',
+};
+
+const outgoingMessagePayload = {
+  content: 'hello',
+  id: 1,
+  message_type: 1,
+  status: 'sent',
+};
+
+describe('#mutations', () => {
+  describe('#pushMessageToConversation', () => {
+    it('add message to conversation if outgoing', () => {
+      const state = { conversations: {} };
+      mutations.pushMessageToConversation(state, outgoingMessagePayload);
+      expect(state.conversations).toEqual({
+        1: outgoingMessagePayload,
+      });
+    });
+
+    it('add message to conversation if message in undelivered', () => {
+      const state = { conversations: {} };
+      mutations.pushMessageToConversation(state, temporaryMessagePayload);
+      expect(state.conversations).toEqual({
+        1: temporaryMessagePayload,
+      });
+    });
+
+    it('replaces temporary message in conversation with actual message', () => {
+      const state = {
+        conversations: {
+          rand_id_123: {
+            content: 'hello',
+            id: 'rand_id_123',
+            message_type: 0,
+            status: 'in_progress',
+          },
+        },
+      };
+      mutations.pushMessageToConversation(state, incomingMessagePayload);
+      expect(state.conversations).toEqual({
+        1: incomingMessagePayload,
+      });
+    });
+
+    it('adds message in conversation if it is a new message', () => {
+      const state = { conversations: {} };
+      mutations.pushMessageToConversation(state, incomingMessagePayload);
+      expect(state.conversations).toEqual({
+        1: incomingMessagePayload,
+      });
+    });
+  });
+
+  describe('#setConversationListLoading', () => {
+    it('set status correctly', () => {
+      const state = { uiFlags: { isFetchingList: false } };
+      mutations.setConversationListLoading(state, true);
+      expect(state.uiFlags.isFetchingList).toEqual(true);
+    });
+  });
+
+  describe('#setMessagesInConversation', () => {
+    it('sets allMessagesLoaded flag if payload is empty', () => {
+      const state = { uiFlags: { allMessagesLoaded: false } };
+      mutations.setMessagesInConversation(state, []);
+      expect(state.uiFlags.allMessagesLoaded).toEqual(true);
+    });
+
+    it('sets messages if payload is not empty', () => {
+      const state = {
+        uiFlags: { allMessagesLoaded: false },
+        conversations: {},
+      };
+      mutations.setMessagesInConversation(state, [{ id: 1, content: 'hello' }]);
+      expect(state.conversations).toEqual({
+        1: { id: 1, content: 'hello' },
+      });
+      expect(state.uiFlags.allMessagesLoaded).toEqual(false);
+    });
+  });
+});