diff --git a/src/components/ChatWidget.vue b/src/components/ChatWidget.vue
index 7a84816..c6817c4 100644
--- a/src/components/ChatWidget.vue
+++ b/src/components/ChatWidget.vue
@@ -76,6 +76,8 @@ export default {
                 console.log('Opey Status: ', this.opeyContext.status)
             } catch (error) {
                 console.error('Error in chat:', error);
+                // on error, remove the assistant message placeholder, as it will be empty.
+                this.opeyContext.messages = this.opeyContext.messages.filter(m => m.id !== this.opeyContext.currentAssistantMessage.id);
                 this.opeyContext.status = 'ready';
             }
         },
diff --git a/src/obp/opey-functions.ts b/src/obp/opey-functions.ts
index eb07d4a..230a7e2 100644
--- a/src/obp/opey-functions.ts
+++ b/src/obp/opey-functions.ts
@@ -87,12 +87,16 @@ export async function sendOpeyMessage(
         if (!stream) {
             throw new Error('No stream returned from API')
         }
+
+        if (response.status !== 200) {
+            throw new Error(`Error sending Opey message: ${response.statusText}`);
+        }
     
         await processOpeyStream(stream, context);
     } catch (error) {
         console.error('Error sending Opey message:', error);
         context.status = 'ready';
-        throw error;
+        throw new Error(`Error sending Opey message: ${error}`);
     }
 
 }
\ No newline at end of file
diff --git a/src/test/ChatWidget.test.ts b/src/test/ChatWidget.test.ts
index 27d1b8f..52f5f47 100644
--- a/src/test/ChatWidget.test.ts
+++ b/src/test/ChatWidget.test.ts
@@ -1,9 +1,77 @@
 import { mount } from '@vue/test-utils';
-import { describe, it, expect } from 'vitest';
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
 import ChatWidget from '../components/ChatWidget.vue'
+import { OpeyStreamContext } from '@/obp/opey-functions';
 
 describe('ChatWidget', () => {
-    it('should append messages in correct order', async () => {
+    let mockContext: OpeyStreamContext;
+
+    beforeEach(() => {
+        mockContext = {
+            currentAssistantMessage: {
+                id: '123',
+                role: 'assistant',
+                content: '',
+            },
+            messages: [],
+            status: 'loading',
+        }  
+
+        // create a mock stream
+        const mockStream = new ReadableStream<Uint8Array>({
+            start(controller) {
+                controller.enqueue(new TextEncoder().encode(`data: {"type":"token","content":"test"}\n`));
+                controller.close();
+            },
+        });
+
+        // mock the fetch function
+        global.fetch = vi.fn(() =>
+            Promise.resolve(new Response(mockStream, {
+                headers: { 'content-type': 'text/event-stream' },
+                status: 200,
+            }))
+        );
+    })
+    afterEach(() => {
+        vi.clearAllMocks()
+    })
+    it('should call fetch when sending a user message', async () => {
+        const wrapper = mount(ChatWidget, {})
+
+        await wrapper.vm.onSubmit()
+        expect(global.fetch).toHaveBeenCalled()
+    })
+    it('should clear the assistant message placeholder from messages list on error', async () => {
+        // mock the fetch function with a rejected promise
+        const wrapper = mount(ChatWidget, {})
+
+        global.fetch = vi.fn(() =>
+            Promise.reject(new Error('Test error'))
+        );
+
+        await wrapper.vm.onSubmit()
+        expect(wrapper.vm.opeyContext.messages.find(m => m.id === wrapper.vm.opeyContext.currentAssistantMessage.id)).toBeUndefined()
+
+
+    })
+    it('should trigger onSubmit when enter key is pressed in the input', async () => {
+        const wrapper = mount(ChatWidget, {})
         
+        // This opens the chat widget
+        wrapper.vm.chatOpen = true
+        await wrapper.vm.$nextTick()
+
+        // Get the input element and trigger the keypress enter event
+        // This will probably fail if the class name of the input element changes
+        const input = wrapper.get('.user-input-container input')
+        input.trigger('keypress.enter')
+        expect(global.fetch).toHaveBeenCalled()
+    })
+    it('displays chat when chatOpen is set to true', async () => {
+        const wrapper = mount(ChatWidget, {})
+        wrapper.vm.chatOpen = true
+        await wrapper.vm.$nextTick()
+        expect(wrapper.find('.chat-container').exists()).toBe(true)
     })
 })
\ No newline at end of file
diff --git a/src/test/opey-functions.test.ts b/src/test/opey-functions.test.ts
index 0e531bf..e69edaa 100644
--- a/src/test/opey-functions.test.ts
+++ b/src/test/opey-functions.test.ts
@@ -135,7 +135,7 @@ describe('sendOpeyMessage', () => {
 
         expect(global.fetch).toHaveBeenCalled()
     })
-    it("should push the 'ready' status to the context", async () => {
+    it("should push the 'ready' status to the context after success", async () => {
 
         await OpeyModule.sendOpeyMessage('test message', '123', false, mockContext)
 
diff --git a/vite.config.mts b/vite.config.mts
index b53563c..946dc00 100644
--- a/vite.config.mts
+++ b/vite.config.mts
@@ -45,11 +45,4 @@ export default defineConfig({
       },
     },
   },
-  test: {
-    // enable jest-like global test APIs
-    globals: true,
-    // simulate DOM with happy-dom
-    // (requires installing happy-dom as a peer dependency)
-    environment: 'happy-dom'
-  },
 })
diff --git a/vitest.config.js b/vitest.config.js
index 83ccc58..ad18ac0 100644
--- a/vitest.config.js
+++ b/vitest.config.js
@@ -34,6 +34,10 @@ export default defineConfig({
     exclude:[
       ...configDefaults.exclude, 
       '**/backend-tests/*'
-    ]
+    ],
+    pool: "vmThreads",  
+    deps: {
+      inline: ['element-plus'],
+    }
   },
 });
\ No newline at end of file