Handle cases where CustomEvent was not initially sent (#11807)

src/System.Management.Automation/utils/Telemetry.cs

@@ -87,6 +87,9 @@ namespace Microsoft.PowerShell.Telemetry
         // the session identifier
         private static string s_sessionId { get; set; }
 
+        // private semaphore to determine whether we sent the startup telemetry event
+        private static int s_startupEventSent = 0;
+
         /// Use a hashset for quick lookups.
         /// We send telemetry only a known set of modules.
         /// If it's not in the list (initialized in the static constructor), then we report anonymous.
@@ -583,6 +586,8 @@ namespace Microsoft.PowerShell.Telemetry
                 return;
             }
 
+            SendPSCoreStartupTelemetry("hosted");
+
             string metricName = metricId.ToString();
             try
             {
@@ -645,6 +650,12 @@ namespace Microsoft.PowerShell.Telemetry
         /// <param name="mode">The "mode" of the startup.</param>
         internal static void SendPSCoreStartupTelemetry(string mode)
         {
+            // Check if we already sent startup telemetry
+            if (Interlocked.CompareExchange(ref s_startupEventSent, 1, 0) == 1)
+            {
+                return;
+            }
+
             if (!CanSendTelemetry)
             {
                 return;

test/powershell/engine/Basic/Telemetry.Tests.ps1

@@ -128,4 +128,29 @@ Describe "Telemetry for shell startup" -Tag CI {
         $result = & $PWSH -NoProfile -Command '[Microsoft.PowerShell.Telemetry.ApplicationInsightsTelemetry]::CanSendTelemetry'
         $result | Should -Be $expectedValue
     }
+
+    It "Should resend startup event if the semaphore says we haven't sent telemetry" {
+
+        $resultJson = & $PWSH -NoProfile -c {
+            $telemetryType = [Microsoft.PowerShell.Telemetry.ApplicationInsightsTelemetry]
+            $bindingFlags = [System.Reflection.BindingFlags]"NonPublic,Static"
+            $initialValue = ${telemetryType}.GetMember("s_startupEventSent", $bindingFlags)[0].GetValue($null)
+            # force a resend of the startup telemetry
+            $null = ${telemetryType}.GetMember("s_startupEventSent", $bindingFlags)[0].SetValue($null,0)
+            $null = Get-Date | Out-String
+            # now check it again, it should be true now that something has executed
+            $finalValue = ${telemetryType}.GetMember("s_startupEventSent", $bindingFlags)[0].GetValue($null)
+            @{
+                initialValue = $initialValue
+                finalValue = $finalValue
+            } | ConvertTo-Json -Compress
+        }
+
+        $result = $resultJson | ConvertFrom-Json
+
+        $result.InitialValue | Should -Be 1  -Because "Should have sent telemetry on console startup"
+
+        $result.FinalValue | Should -Be 1  -Because "Should have resent telemetry"
+    }
+
 }