feat: implement unregister functionality for extracurricular activities and add corresponding tests

Author: Subrojit-Roy

requirements.txt

@@ -1,2 +1,6 @@
 fastapi
 uvicorn
+
+# Test dependencies
+pytest
+httpx

src/app.py

@@ -1,3 +1,4 @@
+
 """
 High School Management System API
 
@@ -107,3 +108,15 @@ 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.post("/activities/{activity_name}/unregister")
+def unregister_from_activity(activity_name: str, email: str):
+    """Remove a student 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="Student is not registered for this activity")
+    activity["participants"].remove(email)
+    return {"message": f"Removed {email} from {activity_name}"}

src/static/app.js

@@ -74,6 +74,8 @@ document.addEventListener("DOMContentLoaded", () => {
           participantsDiv.appendChild(none);
         } else {
           const list = document.createElement("ul");
+          list.style.listStyle = "none";
+          list.style.padding = "0";
           participants.forEach((p) => {
             const { display, initials } = nameFromIdentifier(p);
             const li = document.createElement("li");
@@ -84,6 +86,25 @@ document.addEventListener("DOMContentLoaded", () => {
 
             li.appendChild(span);
             li.appendChild(document.createTextNode(" " + display));
+
+            // Add delete icon
+            const delBtn = document.createElement("button");
+            delBtn.className = "delete-participant";
+            delBtn.title = "Remove participant";
+            delBtn.innerHTML = "🗑"; // trash can icon
+            delBtn.style.marginLeft = "8px";
+            delBtn.style.background = "none";
+            delBtn.style.border = "none";
+            delBtn.style.cursor = "pointer";
+            delBtn.style.color = "#c62828";
+            delBtn.style.fontSize = "15px";
+            delBtn.setAttribute("aria-label", `Remove ${display}`);
+            delBtn.addEventListener("click", (e) => {
+              e.stopPropagation();
+              unregisterParticipant(name, p);
+            });
+            li.appendChild(delBtn);
+
             list.appendChild(li);
           });
           participantsDiv.appendChild(list);
@@ -148,4 +169,30 @@ document.addEventListener("DOMContentLoaded", () => {
 
   // Initialize app
   fetchActivities();
+  // Unregister participant function
+  async function unregisterParticipant(activityName, participantId) {
+    if (!confirm("Are you sure you want to remove this participant?")) return;
+    try {
+      const response = await fetch(`/activities/${encodeURIComponent(activityName)}/unregister?email=${encodeURIComponent(participantId)}`, {
+        method: "POST"
+      });
+      const result = await response.json();
+      if (response.ok) {
+        messageDiv.textContent = result.message || "Participant removed.";
+        messageDiv.className = "success";
+        await fetchActivities();
+      } else {
+        messageDiv.textContent = result.detail || "Failed to remove participant.";
+        messageDiv.className = "error";
+      }
+      messageDiv.classList.remove("hidden");
+      setTimeout(() => messageDiv.classList.add("hidden"), 5000);
+    } catch (error) {
+      messageDiv.textContent = "Error removing participant.";
+      messageDiv.className = "error";
+      messageDiv.classList.remove("hidden");
+      setTimeout(() => messageDiv.classList.add("hidden"), 5000);
+      console.error("Error unregistering participant:", error);
+    }
+  }
 });

src/static/styles.css

@@ -75,17 +75,35 @@ section h3 {
   margin-bottom: 8px;
 }
 
-.activity-card .participants {
-  margin-top: 12px;
-  padding-top: 10px;
-  border-top: 1px dashed #eee;
+.activity-card .participants ul {
+.activity-card .participants ul {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 8px;
+  padding: 0;
+  margin: 0;
+  list-style: none;
+}
+.activity-card .participants li {
+  position: relative;
 }
 
-.activity-card .participants h5 {
-  margin: 0 0 8px;
-  font-size: 13px;
-  color: #1a237e;
-  font-weight: 600;
+
+button.delete-participant {
+  margin-left: 8px;
+  background: none;
+  border: none;
+  cursor: pointer;
+  color: #c62828;
+  font-size: 15px;
+  padding: 0 2px;
+  vertical-align: middle;
+}
+button.delete-participant:hover {
+  color: #a31515;
+}
+.activity-card .participants ul li::before {
+  display: none !important;
 }
 
 .activity-card .participants ul {

tests/test_api.py

@@ -0,0 +1,49 @@
+from fastapi.testclient import TestClient
+from src.app import app, activities
+
+
+client = TestClient(app)
+
+
+def test_get_activities():
+    resp = client.get("/activities")
+    assert resp.status_code == 200
+    data = resp.json()
+    assert isinstance(data, dict)
+    # Ensure a known activity is present
+    assert "Chess Club" in data
+
+
+def test_signup_and_unregister_flow():
+    activity = "Chess Club"
+    email = "[email protected]"
+
+    # Ensure clean state: remove if already present
+    if email in activities[activity]["participants"]:
+        activities[activity]["participants"].remove(email)
+
+    # Sign up
+    resp = client.post(f"/activities/{activity}/signup", params={"email": email})
+    assert resp.status_code == 200
+    assert email in activities[activity]["participants"]
+
+    # Sign up again -> should fail (already signed up)
+    resp2 = client.post(f"/activities/{activity}/signup", params={"email": email})
+    assert resp2.status_code == 400
+
+    # Unregister
+    resp3 = client.post(f"/activities/{activity}/unregister", params={"email": email})
+    assert resp3.status_code == 200
+    assert email not in activities[activity]["participants"]
+
+
+def test_unregister_nonexistent():
+    activity = "Chess Club"
+    email = "[email protected]"
+
+    # Ensure not registered
+    if email in activities[activity]["participants"]:
+        activities[activity]["participants"].remove(email)
+
+    resp = client.post(f"/activities/{activity}/unregister", params={"email": email})
+    assert resp.status_code == 400