Implement activity unregistration feature and add tests

Author: NSky

.vscode/settings.json

@@ -0,0 +1,7 @@
+{
+    "python.testing.pytestArgs": [
+        "tests"
+    ],
+    "python.testing.unittestEnabled": false,
+    "python.testing.pytestEnabled": true
+}

requirements.txt

@@ -1,2 +1,4 @@
 fastapi
 uvicorn
+pytest
+requests

src/app.py

@@ -105,3 +105,20 @@ def signup_for_activity(activity_name: str, email: str):
     # Add student
     activity["participants"].append(email)
     return {"message": f"Signed up {email} for {activity_name}"}
+
+
+@app.delete("/activities/{activity_name}/unregister")
+def unregister_from_activity(activity_name: str, email: str):
+    """Unregister a student (email) from an activity"""
+    # Validate activity exists
+    if activity_name not in activities:
+        raise HTTPException(status_code=404, detail="Activity not found")
+
+    activity = activities[activity_name]
+
+    # Validate student is currently signed up
+    if email not in activity["participants"]:
+        raise HTTPException(status_code=404, detail="Participant not found in activity")
+
+    activity["participants"].remove(email)
+    return {"message": f"Unregistered {email} from {activity_name}"}

src/static/app.js

@@ -8,6 +8,10 @@ document.addEventListener("DOMContentLoaded", () => {
   async function fetchActivities() {
     try {
       const response = await fetch("/activities");
+      if (!response.ok) {
+        const text = await response.text().catch(() => '');
+        throw new Error(`Failed to fetch activities: ${response.status} ${text}`);
+      }
       const activities = await response.json();
 
       // Clear loading message
@@ -59,8 +63,28 @@ document.addEventListener("DOMContentLoaded", () => {
             nameSpan.className = "participant-name";
             nameSpan.textContent = p;
 
+            // Delete/unregister icon
+            const deleteIcon = document.createElement('span');
+            deleteIcon.className = 'delete-icon';
+            deleteIcon.textContent = '🗑️';
+            deleteIcon.onclick = async () => {
+              try {
+                const res = await fetch(`/activities/${encodeURIComponent(name)}/unregister?email=${encodeURIComponent(p)}`, { method: 'DELETE' });
+                if (!res.ok) {
+                  const err = await res.json().catch(() => ({ detail: 'Unknown error' }));
+                  console.error('Unregister failed:', err);
+                  return;
+                }
+                // Refresh activities list after successful unregister
+                fetchActivities();
+              } catch (e) {
+                console.error('Network error while unregistering:', e);
+              }
+            };
+
             li.appendChild(avatar);
             li.appendChild(nameSpan);
+            li.appendChild(deleteIcon);
             ul.appendChild(li);
           });
 
@@ -101,12 +125,14 @@ document.addEventListener("DOMContentLoaded", () => {
         }
       );
 
-      const result = await response.json();
+      const result = await response.json().catch(() => ({}));
 
       if (response.ok) {
-        messageDiv.textContent = result.message;
+        messageDiv.textContent = result.message || "Signed up successfully";
         messageDiv.className = "success";
         signupForm.reset();
+        // Refresh activities to show the new participant immediately
+        fetchActivities();
       } else {
         messageDiv.textContent = result.detail || "An error occurred";
         messageDiv.className = "error";

src/static/styles.css

@@ -6,6 +6,18 @@
 }
 
 body {
+
+/* Add CSS to hide bullet points for participants list */
+.participants-list {
+  list-style-type: none;
+  padding: 0;
+}
+
+.delete-icon {
+  cursor: pointer;
+  margin-left: 10px;
+  color: red;
+}
   font-family: Arial, sans-serif;
   line-height: 1.6;
   color: #333;

tests/test_app.py

@@ -0,0 +1,65 @@
+import copy
+from fastapi.testclient import TestClient
+import pytest
+
+from src.app import app, activities
+
+client = TestClient(app)
+
+@pytest.fixture(autouse=True)
+def reset_activities():
+    # Make a deep copy of the activities before each test and restore after
+    original = copy.deepcopy(activities)
+    yield
+    activities.clear()
+    activities.update(copy.deepcopy(original))
+
+
+def test_get_activities():
+    res = client.get("/activities")
+    assert res.status_code == 200
+    data = res.json()
+    assert isinstance(data, dict)
+    assert "Football Club" in data
+    assert isinstance(data["Football Club"]["participants"], list)
+
+
+def test_signup_and_unregister_flow():
+    email = "temp@example.com"
+    activity = "Football Club"
+
+    # Sign up
+    res = client.post(f"/activities/{activity}/signup?email={email}")
+    assert res.status_code == 200
+    assert "Signed up" in res.json().get("message", "")
+
+    # Participant should be in the activity
+    assert email in activities[activity]["participants"]
+
+    # Unregister
+    res = client.delete(f"/activities/{activity}/unregister?email={email}")
+    assert res.status_code == 200
+    assert "Unregistered" in res.json().get("message", "")
+
+    # Participant should be removed
+    assert email not in activities[activity]["participants"]
+
+
+def test_signup_existing():
+    activity = "Football Club"
+    email = "alex@mergington.edu"  # already present
+    res = client.post(f"/activities/{activity}/signup?email={email}")
+    assert res.status_code == 400
+    assert "already signed up" in res.json().get("detail", "").lower()
+
+
+def test_unregister_not_found():
+    activity = "Football Club"
+    email = "notfound@example.com"
+
+    # Ensure the participant is not present
+    if email in activities[activity]["participants"]:
+        activities[activity]["participants"].remove(email)
+
+    res = client.delete(f"/activities/{activity}/unregister?email={email}")
+    assert res.status_code == 404