feat: Show connected robots finished with unit test 94% coverage

ref: N25B-142

package-lock.json

@@ -3323,6 +3323,66 @@
         "vite": "^4.2.0 || ^5.0.0 || ^6.0.0 || ^7.0.0"
       }
     },
+    "node_modules/@xyflow/react": {
+      "version": "12.9.1",
+      "resolved": "https://registry.npmjs.org/@xyflow/react/-/react-12.9.1.tgz",
+      "integrity": "sha512-JRPCT5p7NnPdVSIh15AFvUSSm+8GUyz2I6iuBEC1LG2lKgig/L48AM/ImMHCc3ZUCg+AgTOJDaX2fcRyPA9BTA==",
+      "license": "MIT",
+      "dependencies": {
+        "@xyflow/system": "0.0.72",
+        "classcat": "^5.0.3",
+        "zustand": "^4.4.0"
+      },
+      "peerDependencies": {
+        "react": ">=17",
+        "react-dom": ">=17"
+      }
+    },
+    "node_modules/@xyflow/react/node_modules/zustand": {
+      "version": "4.5.7",
+      "resolved": "https://registry.npmjs.org/zustand/-/zustand-4.5.7.tgz",
+      "integrity": "sha512-CHOUy7mu3lbD6o6LJLfllpjkzhHXSBlX8B9+qPddUsIfeF5S/UZ5q0kmCsnRqT1UHFQZchNFDDzMbQsuesHWlw==",
+      "license": "MIT",
+      "dependencies": {
+        "use-sync-external-store": "^1.2.2"
+      },
+      "engines": {
+        "node": ">=12.7.0"
+      },
+      "peerDependencies": {
+        "@types/react": ">=16.8",
+        "immer": ">=9.0.6",
+        "react": ">=16.8"
+      },
+      "peerDependenciesMeta": {
+        "@types/react": {
+          "optional": true
+        },
+        "immer": {
+          "optional": true
+        },
+        "react": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@xyflow/system": {
+      "version": "0.0.72",
+      "resolved": "https://registry.npmjs.org/@xyflow/system/-/system-0.0.72.tgz",
+      "integrity": "sha512-WBI5Aau0fXTXwxHPzceLNS6QdXggSWnGjDtj/gG669crApN8+SCmEtkBth1m7r6pStNo/5fI9McEi7Dk0ymCLA==",
+      "license": "MIT",
+      "dependencies": {
+        "@types/d3-drag": "^3.0.7",
+        "@types/d3-interpolate": "^3.0.4",
+        "@types/d3-selection": "^3.0.10",
+        "@types/d3-transition": "^3.0.8",
+        "@types/d3-zoom": "^3.0.8",
+        "d3-drag": "^3.0.0",
+        "d3-interpolate": "^3.0.1",
+        "d3-selection": "^3.0.0",
+        "d3-zoom": "^3.0.0"
+      }
+    },
     "node_modules/acorn": {
       "version": "8.15.0",
       "resolved": "https://registry.npmjs.org/acorn/-/acorn-8.15.0.tgz",
@@ -7677,6 +7737,15 @@
         "punycode": "^2.1.0"
       }
     },
+    "node_modules/use-sync-external-store": {
+      "version": "1.6.0",
+      "resolved": "https://registry.npmjs.org/use-sync-external-store/-/use-sync-external-store-1.6.0.tgz",
+      "integrity": "sha512-Pp6GSwGP/NrPIrxVFAIkOQeyw8lFenOHijQWkUTrDvrF4ALqylP2C/KCkeS9dpUM3KvYRQhna5vt7IL95+ZQ9w==",
+      "license": "MIT",
+      "peerDependencies": {
+        "react": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0"
+      }
+    },
     "node_modules/v8-to-istanbul": {
       "version": "9.3.0",
       "resolved": "https://registry.npmjs.org/v8-to-istanbul/-/v8-to-istanbul-9.3.0.tgz",
@@ -8159,6 +8228,35 @@
       "funding": {
         "url": "https://github.com/sponsors/sindresorhus"
       }
+    },
+    "node_modules/zustand": {
+      "version": "5.0.8",
+      "resolved": "https://registry.npmjs.org/zustand/-/zustand-5.0.8.tgz",
+      "integrity": "sha512-gyPKpIaxY9XcO2vSMrLbiER7QMAMGOQZVRdJ6Zi782jkbzZygq5GI9nG8g+sMgitRtndwaBSl7uiqC49o1SSiw==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=12.20.0"
+      },
+      "peerDependencies": {
+        "@types/react": ">=18.0.0",
+        "immer": ">=9.0.6",
+        "react": ">=18.0.0",
+        "use-sync-external-store": ">=1.2.0"
+      },
+      "peerDependenciesMeta": {
+        "@types/react": {
+          "optional": true
+        },
+        "immer": {
+          "optional": true
+        },
+        "react": {
+          "optional": true
+        },
+        "use-sync-external-store": {
+          "optional": true
+        }
+      }
     }
   }
 }

src/App.tsx

@@ -1,5 +1,4 @@
 import { Routes, Route, Link } from 'react-router'
-import { useState } from 'react'
 import './App.css'
 import TemplatePage from './pages/TemplatePage/Template.tsx'
 import Home from './pages/Home/Home.tsx'
@@ -9,16 +8,6 @@ import VisProg from "./pages/VisProgPage/VisProg.tsx";
 
 function App(){
 
-  // Define what our conencted robot should include
-  type Robot = {
-  id: string;
-  name: string;
-  port: number;
-  }; 
-
-  // (Acces to) the array of connected robots
-  const [connectedRobots, setConnectedRobots] = useState<Robot[]>([]);
-
   return (
     <div>
       <header>
@@ -30,16 +19,7 @@ function App(){
           <Route path="/template" element={<TemplatePage />} />
           <Route path="/editor" element={<VisProg />} />
           <Route path="/robot" element={<Robot />} />
-          <Route
+          <Route path="/ConnectedRobots" element={<ConnectedRobots />} />
-          path="/ConnectedRobots"
-          // Pass the useState to the page to update from there
-          element={
-            <ConnectedRobots
-               connectedRobots={connectedRobots}
-               setConnectedRobots={setConnectedRobots}
-             />
-            }
-          />
         </Routes>
       </main>
     </div>

src/pages/ConnectedRobots/ConnectedRobots.tsx

@@ -3,6 +3,9 @@ import { useEffect, useState } from 'react'
 export default function ConnectedRobots() {
   
   const [connected, setConnected] = useState<boolean | null>(null);
+
+  
+
   useEffect(() => {
     // We're excepting a stream of data like that looks like this: `data = False` or `data = True`
     const eventSource = new EventSource("http://localhost:8000/robot/ping_stream");
@@ -33,6 +36,9 @@ export default function ConnectedRobots() {
       <h1>Is robot currently connected?</h1>
       <div>
         <h2>Robot is currently: {connected == null ? "checking..." : (connected ? "connected! 🟢" : "not connected... 🔴")} </h2>
+        <h3>
+          {connected == null ? "If checking continues, make sure CB is properly loaded with robot at least once." : ""}
+        </h3>
       </div>
     </div>
   );

test/pages/connectedRobots/ConnectedRobots.test.tsx

@@ -0,0 +1,102 @@
+import { render, screen, act, cleanup, waitFor } from '@testing-library/react';
+import ConnectedRobots from '../../../src/pages/ConnectedRobots/ConnectedRobots';
+
+// Mock event source
+const mockInstances: MockEventSource[] = [];
+class MockEventSource {
+  url: string;
+  onmessage: ((event: MessageEvent) => void) | null = null;
+  closed = false;
+
+  constructor(url: string) {
+    this.url = url;
+    mockInstances.push(this);
+  }
+
+  sendMessage(data: any) {
+    // Trigger whatever the component listens to
+    this.onmessage?.({ data } as MessageEvent);
+  }
+
+  close() {
+    this.closed = true;
+  }
+}
+
+// mock event source generation with fake function that returns our fake mock source
+beforeAll(() => {
+  (globalThis as any).EventSource = jest.fn((url: string) => new MockEventSource(url));
+});
+
+// clean after tests
+afterEach(() => {
+  cleanup();
+  jest.restoreAllMocks();
+  mockInstances.length = 0;
+});
+
+describe('ConnectedRobots', () => {
+  test('renders initial state correctly', () => {
+    render(<ConnectedRobots />);
+    
+    // Check initial texts (before connection)
+    expect(screen.getByText('Is robot currently connected?')).toBeInTheDocument();
+    expect(screen.getByText(/Robot is currently:\s*checking/i)).toBeInTheDocument();
+    expect(
+      screen.getByText(/If checking continues, make sure CB is properly loaded/i)
+    ).toBeInTheDocument();
+  });
+
+  test('updates to connected when message data is true', async () => {
+    render(<ConnectedRobots />);
+    const eventSource = mockInstances[0];
+    expect(eventSource).toBeDefined();
+
+    // Check state after getting 'true' message
+    await act(async () => {
+      eventSource.sendMessage('true');
+    });
+
+    await waitFor(() => {
+      expect(screen.getByText(/connected! 🟢/i)).toBeInTheDocument();
+    });
+  });
+
+  test('updates to not connected when message data is false', async () => {
+    render(<ConnectedRobots />);
+    const eventSource = mockInstances[0];
+
+    // Check statew after getting 'false' message
+    await act(async () => {
+      eventSource.sendMessage('false');
+    });
+
+    await waitFor(() => {
+      expect(screen.getByText(/not connected.*🔴/i)).toBeInTheDocument();
+    });
+  });
+
+  test('handles invalid JSON gracefully', async () => {
+    const logSpy = jest.spyOn(console, 'log').mockImplementation(() => {});
+    render(<ConnectedRobots />);
+    const eventSource = mockInstances[0];
+
+    await act(async () => {
+      eventSource.sendMessage('not-json');
+    });
+
+    expect(logSpy).toHaveBeenCalledWith(
+      'Ping message not in correct format:',
+      'not-json'
+    );
+  });
+
+  test('closes EventSource on unmount', () => {
+    render(<ConnectedRobots />);
+    const eventSource = mockInstances[0];
+    const closeSpy = jest.spyOn(eventSource, 'close');
+    cleanup(); 
+    expect(closeSpy).toHaveBeenCalled();
+    expect(eventSource.closed).toBe(true);
+  });
+});