test(analytics): add Splunk HEC connection test script

- Create Node.js test script for HEC endpoint validation
- Include comprehensive error handling and response logging
- Test event format matches Splunk HEC requirements
- Provide clear success/failure feedback for configuration testing

Author: afernandez-nhs

docs/test-splunk-hec.js

@@ -0,0 +1,86 @@
+/**
+ * Test script for Splunk HEC connection
+ * Run this in Node.js to test your Splunk HEC setup
+ */
+
+const https = require('https');
+
+// Configuration - UPDATE THESE VALUES
+const SPLUNK_ENDPOINT = 'https://splunk-instance.nhs.uk:8088/services/collector';
+const SPLUNK_TOKEN = 'hec-token-placeholder';
+
+// Test event data
+const testEvent = {
+    event: {
+        timestamp: new Date().toISOString(),
+        session_id: 'test_session_123',
+        environment: 'test',
+        user_agent: 'Test Script',
+        page_url: 'http://localhost:4000/test',
+        page_title: 'Test Page',
+        page_path: '/test',
+        referrer: 'http://localhost:4000/',
+        event_type: 'test_event',
+        event_category: 'test',
+        event_action: 'test',
+        event_label: 'HEC Test',
+        event_value: 1,
+        test_message: 'This is a test event from NHS Notify Web CMS'
+    },
+    sourcetype: 'nhs_notify_frontend_events',
+    index: 'events_nhsnotify_nonprod',
+    host: 'test-host'
+};
+
+// Function to send test event
+function sendTestEvent() {
+    const postData = JSON.stringify(testEvent);
+
+    const options = {
+        hostname: new URL(SPLUNK_ENDPOINT).hostname,
+        port: new URL(SPLUNK_ENDPOINT).port || 443,
+        path: new URL(SPLUNK_ENDPOINT).pathname,
+        method: 'POST',
+        headers: {
+            'Content-Type': 'application/json',
+            'Authorization': `Splunk ${SPLUNK_TOKEN}`,
+            'Content-Length': Buffer.byteLength(postData)
+        }
+    };
+
+    const req = https.request(options, (res) => {
+        console.log(`Status: ${res.statusCode}`);
+        console.log(`Headers: ${JSON.stringify(res.headers)}`);
+
+        let data = '';
+        res.on('data', (chunk) => {
+            data += chunk;
+        });
+
+        res.on('end', () => {
+            console.log('Response:', data);
+            if (res.statusCode === 200) {
+                console.log('✅ SUCCESS: Test event sent to Splunk successfully!');
+                console.log('Check your Splunk index "events_nhsnotify_nonprod" for the test event.');
+            } else {
+                console.log('❌ FAILED: Test event failed to send to Splunk.');
+            }
+        });
+    });
+
+    req.on('error', (err) => {
+        console.error('❌ ERROR:', err.message);
+        console.log('Check your Splunk endpoint and token configuration.');
+    });
+
+    req.write(postData);
+    req.end();
+}
+
+// Run the test
+console.log('🚀 Testing Splunk HEC connection...');
+console.log('Endpoint:', SPLUNK_ENDPOINT);
+console.log('Token:', SPLUNK_TOKEN.substring(0, 10) + '...');
+console.log('');
+
+sendTestEvent();