Implement participant unregistration feature and update UI for activity cards

Author: Muhammadulawal

requirements.txt

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

src/app.py

@@ -108,3 +108,18 @@ def signup_for_activity(activity_name: str, email: str):
     # Add student
     activity["participants"].append(email)
     return {"message": f"Signed up {email} for {activity_name}"}
+
+
+# Unregister a participant from an activity
+from fastapi import Query
+
+@app.delete("/activities/{activity_name}/unregister")
+def unregister_from_activity(activity_name: str, email: str = Query(...)):
+    """Remove a participant from an activity"""
+    if activity_name not in activities:
+        raise HTTPException(status_code=404, detail="Activity not found")
+    activity = activities[activity_name]
+    if email not in activity["participants"]:
+        raise HTTPException(status_code=400, detail="Participant not found in this activity")
+    activity["participants"].remove(email)
+    return {"message": f"Unregistered {email} from {activity_name}"}

src/static/app.js

@@ -22,24 +22,29 @@ document.addEventListener("DOMContentLoaded", () => {
 
 
           // Create participants list HTML
-          let participantsHTML = '';
-          if (details.participants.length > 0) {
-            participantsHTML = `
-              <div class="participants-section">
-                <strong>Participants:</strong>
-                <ul>
-                  ${details.participants.map(p => `<li>${p}</li>`).join('')}
-                </ul>
-              </div>
-            `;
-          } else {
-            participantsHTML = `
-              <div class="participants-section empty">
-                <strong>Participants:</strong>
-                <p>No one has signed up yet.</p>
-              </div>
-            `;
-          }
+        let participantsHTML = '';
+        if (details.participants.length > 0) {
+          participantsHTML = `
+            <div class="participants-section">
+              <strong>Participants:</strong>
+              <ul class="participants-list">
+                ${details.participants.map(p => `
+                  <li class="participant-item">
+                    <span class="participant-email">${p}</span>
+                    <span class="delete-participant" title="Unregister" data-activity="${name}" data-email="${p}">&#128465;</span>
+                  </li>
+                `).join('')}
+              </ul>
+            </div>
+          `;
+        } else {
+          participantsHTML = `
+            <div class="participants-section empty">
+              <strong>Participants:</strong>
+              <p>No one has signed up yet.</p>
+            </div>
+          `;
+        }
 
           activityCard.innerHTML = `
             <h4>${name}</h4>
@@ -51,6 +56,33 @@ document.addEventListener("DOMContentLoaded", () => {
 
         activitiesList.appendChild(activityCard);
 
+          // Add event listeners for delete icons
+          activityCard.querySelectorAll('.delete-participant').forEach(icon => {
+            icon.addEventListener('click', async (e) => {
+              const activityName = icon.getAttribute('data-activity');
+              const email = icon.getAttribute('data-email');
+              if (confirm(`Unregister ${email} from ${activityName}?`)) {
+                try {
+                  const response = await fetch(`/activities/${encodeURIComponent(activityName)}/unregister?email=${encodeURIComponent(email)}`, {
+                    method: 'DELETE',
+                  });
+                  const result = await response.json();
+                  if (response.ok) {
+                    fetchActivities(); // Refresh list
+                    messageDiv.textContent = result.message;
+                    messageDiv.style.color = 'green';
+                  } else {
+                    messageDiv.textContent = result.detail || 'Failed to unregister.';
+                    messageDiv.style.color = 'red';
+                  }
+                } catch (err) {
+                  messageDiv.textContent = 'Error unregistering participant.';
+                  messageDiv.style.color = 'red';
+                }
+              }
+            });
+          });
+
         // Add option to select dropdown
         const option = document.createElement("option");
         option.value = name;

src/static/styles.css

@@ -91,18 +91,38 @@ section h3 {
   margin-bottom: 6px;
 }
 
-.participants-section ul {
-  list-style-type: disc;
-  margin-left: 20px;
+
+.participants-list {
+  list-style-type: none;
+  margin-left: 0;
   margin-bottom: 0;
+  padding-left: 0;
 }
 
-.participants-section li {
+.participant-item {
+  display: flex;
+  align-items: center;
   margin-bottom: 4px;
   color: #333;
   font-size: 14px;
 }
 
+.participant-email {
+  flex: 1;
+}
+
+.delete-participant {
+  cursor: pointer;
+  color: #d32f2f;
+  margin-left: 10px;
+  font-size: 16px;
+  transition: color 0.2s;
+}
+.delete-participant:hover {
+  color: #b71c1c;
+  text-shadow: 0 0 2px #d32f2f;
+}
+
 .participants-section.empty {
   background: #fffde7;
   border: 1px solid #ffe082;

tests/test_app.py

@@ -0,0 +1,61 @@
+import pytest
+from fastapi.testclient import TestClient
+from src.app import app
+
+client = TestClient(app)
+
+# Test GET /activities
+def test_get_activities():
+    response = client.get("/activities")
+    assert response.status_code == 200
+    data = response.json()
+    assert "Chess Club" in data
+    assert "Programming Class" in data
+    assert "Gym Class" in data
+
+# Test POST /activities/{activity_name}/signup
+@pytest.mark.parametrize("activity,email", [
+    ("Chess Club", "newstudent@mergington.edu"),
+    ("Programming Class", "newcoder@mergington.edu"),
+])
+def test_signup_for_activity(activity, email):
+    response = client.post(f"/activities/{activity}/signup?email={email}")
+    assert response.status_code == 200
+    assert f"Signed up {email} for {activity}" in response.json()["message"]
+
+# Test duplicate signup
+def test_duplicate_signup():
+    activity = "Chess Club"
+    email = "michael@mergington.edu"
+    response = client.post(f"/activities/{activity}/signup?email={email}")
+    assert response.status_code == 400
+    assert "already signed up" in response.json()["detail"]
+
+# Test DELETE /activities/{activity_name}/unregister
+@pytest.mark.parametrize("activity,email", [
+    ("Chess Club", "daniel@mergington.edu"),
+    ("Programming Class", "emma@mergington.edu"),
+])
+def test_unregister_from_activity(activity, email):
+    response = client.delete(f"/activities/{activity}/unregister?email={email}")
+    assert response.status_code == 200
+    assert f"Unregistered {email} from {activity}" in response.json()["message"]
+
+# Test unregister non-existent participant
+def test_unregister_nonexistent():
+    activity = "Chess Club"
+    email = "notfound@mergington.edu"
+    response = client.delete(f"/activities/{activity}/unregister?email={email}")
+    assert response.status_code == 400
+    assert "Participant not found" in response.json()["detail"]
+
+# Test activity not found
+@pytest.mark.parametrize("endpoint", [
+    "/activities/Unknown/signup?email=test@mergington.edu",
+    "/activities/Unknown/unregister?email=test@mergington.edu",
+])
+def test_activity_not_found(endpoint):
+    method = "post" if "signup" in endpoint else "delete"
+    response = getattr(client, method)(endpoint)
+    assert response.status_code == 404
+    assert "Activity not found" in response.json()["detail"]