we have some working output

src/index.js

@@ -32,8 +32,10 @@ module.exports = async function (context, req) {
       uniqueId: telemetry.uniqueId(),
       header: telemetry.headers, // Assuming this contains the parsed header data
       sessionInfo: telemetry.sessionInfo, // Contains the parsed YAML session info
-      varHeaders: telemetry.varHeaders, // Assuming this method returns the variable headers
-      telemetryData: telemetry.getTelemetryDataSummary()
+      varHeaders: telemetry.varHeaders // Assuming this method returns the variable headers
+      // Add a method to extract summarized telemetry data
+      // telemetryData: telemetry.getTelemetryDataSummary()
+      // You can add more methods as needed to extract different parts of the telemetry data
     }
 
     // Response

src/utils/telemetry-file-loader.js

@@ -44,14 +44,27 @@ const sessionInfoStringFromFileDescriptor = (fd, telemetryHeader) => {
 }
 
 const varHeadersFromFileDescriptor = (fd, telemetryHeader) => {
+  // Add logging
+  console.log('Num vars:', telemetryHeader.numVars)
   if (!isNumber(telemetryHeader.numVars, 'numVars')) {
     return Promise.reject(new Error('Invalid number of variables (numVars)'))
   }
 
   const numberOfVariables = telemetryHeader.numVars
   const startPosition = telemetryHeader.varHeaderOffset
+
+  // Add check before using in buffer size
+  if (!isNumber(numberOfVariables)) {
+    return Promise.reject(new Error('Invalid numVars'))
+  }
+
   const fullBufferSize = numberOfVariables * VAR_HEADER_SIZE_IN_BYTES
 
+  // Add check before passing to read buffer
+  if (!isNumber(fullBufferSize)) {
+    return Promise.reject(new Error('Invalid buffer size'))
+  }
+
   return readFileToBuffer(fd, startPosition, fullBufferSize)
     .then(buffer => {
       return R.range(0, numberOfVariables).map(count => {