Throw Connect-MgGraph required when auth session in null.

src/Authentication/Authentication/Helpers/HttpHelpers.cs

@@ -25,7 +25,7 @@ public static HttpClient GetGraphHttpClient()
             if (GraphSession.Instance?.GraphHttpClient != null)
                 return GraphSession.Instance.GraphHttpClient;
 
-            var requestUserAgent = new RequestUserAgent(GraphSession.Instance.AuthContext.PSHostVersion, null);
+            var requestUserAgent = new RequestUserAgent(GraphSession.Instance.AuthContext?.PSHostVersion, null);
 
             IAuthenticationProvider authProvider = AuthenticationHelpers.GetAuthenticationProviderAsync(GraphSession.Instance.AuthContext).ConfigureAwait(false).GetAwaiter().GetResult();
             var newHttpClient = GetGraphHttpClient(authProvider, GraphSession.Instance.RequestContext);

src/Users/v1.0/test/Users.Tests.ps1

@@ -0,0 +1,61 @@
+# ------------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation. All Rights Reserved. Licensed under the MIT License. See License in the project root for license information.
+# ------------------------------------------------------------------------------
+Describe "Microsoft.Graph.Users Module" {
+    Context "On module import" {
+        BeforeAll {
+            $ModuleName = "Microsoft.Graph.Users"
+            $ModulePath = Join-Path $PSScriptRoot "..\$ModuleName.psd1"
+            $PSModuleInfo = Get-Module $ModuleName
+        }
+
+        It "Should have exported commands" {
+            $PSModuleInfo | Should -Not -Be $null
+            $PSModuleInfo.ExportedCommands.Count | Should -Not -Be 0
+        }
+
+        It 'Should be compatible with PS core and desktop' {
+            $PSModuleInfo.CompatiblePSEditions | Should -BeIn @("Core", "Desktop")
+        }
+
+        It 'Should point to script module' {
+            $PSModuleInfo.Path | Should -BeLikeExactly "*$ModuleName.psm1"
+        }
+
+        It 'Should have a definition' {
+            $PSModuleInfo.Definition | Should -Not -BeNullOrEmpty
+        }
+
+        It 'Should lock GUID' {
+            $PSModuleInfo.Guid.Guid | Should -Be "71150504-37a3-48c6-82c7-7a00a12168db"
+        }
+
+        It "Module import should not write to error and information streams" {
+            $ps = [powershell]::Create()
+            $ps.AddScript("Import-Module $ModulePath -ErrorAction SilentlyContinue").Invoke()
+
+            $ps.Streams.Information.Count | Should -Be 0
+            $ps.Streams.Error.Count | Should -Be 0
+            $ps.Streams.Verbose.Count | Should -Be 0
+            $ps.Streams.Warning.Count | Should -Be 0
+            $ps.Streams.Progress.Count | Should -Be 0
+
+            $ps.Dispose()
+        }
+
+        It "Get-MgUser should fail when auth session hasn't been initialized" {
+            $ps = [powershell]::Create()
+            $ps.AddScript("Import-Module $ModulePath -ErrorAction SilentlyContinue").Invoke()
+            $ps.AddScript("Get-MgUser").Invoke()
+
+            $ps.Streams.Information.Count | Should -Be 0
+            $ps.Streams.Verbose.Count | Should -Be 0
+            $ps.Streams.Warning.Count | Should -Be 0
+            $ps.Streams.Progress.Count | Should -Be 0
+
+            $ps.Streams.Error | Should -Be "$([Microsoft.Graph.PowerShell.Authentication.Core.ErrorConstants+Message]::MissingAuthContext)"
+
+            $ps.Dispose()
+        }
+    }
+}