[Storage] Set StaticWebsite properties IndexDocument and ErrorDocument404Path to optional.

Author: blueww

src/Storage/Storage.Management/ChangeLog.md

@@ -18,6 +18,8 @@
         - Additional information about change #1
 -->
 ## Upcoming Release
+* Change 2 parameters "-IndexDocument" and "-ErrorDocument404Path" from required to optional  in cmdlet:
+    -  Enable-AzStorageStaticWebsite
 * Show more error information when cmdlet failed with StorageException 
 
 ## Version 1.4.0

src/Storage/Storage.Management/help/Enable-AzStorageStaticWebsite.md

@@ -1,4 +1,4 @@
----
+---
 external help file: Microsoft.Azure.PowerShell.Cmdlets.Storage.dll-Help.xml
 Module Name: Az.Storage
 online version: https://docs.microsoft.com/en-us/powershell/module/az.storage/enable-azstoragestaticwebsite
@@ -13,7 +13,7 @@ Enable static website for the Azure Storage account.
 ## SYNTAX
 
 ```
-Enable-AzStorageStaticWebsite [-IndexDocument] <String> [-ErrorDocument404Path] <String> [-PassThru]
+Enable-AzStorageStaticWebsite [[-IndexDocument] <String>] [[-ErrorDocument404Path] <String>] [-PassThru]
  [-Context <IStorageContext>] [-DefaultProfile <IAzureContextContainer>] [-WhatIf] [-Confirm]
  [<CommonParameters>]
 ```
@@ -70,7 +70,7 @@ Type: System.String
 Parameter Sets: (All)
 Aliases:
 
-Required: True
+Required: False
 Position: 1
 Default value: None
 Accept pipeline input: False
@@ -85,15 +85,15 @@ Type: System.String
 Parameter Sets: (All)
 Aliases:
 
-Required: True
+Required: False
 Position: 0
 Default value: None
 Accept pipeline input: False
 Accept wildcard characters: False
 ```
 
 ### -PassThru
-{{Fill PassThru Description}}
+Display Static Website setting in ServiceProperties.
 
 ```yaml
 Type: System.Management.Automation.SwitchParameter

src/Storage/Storage/Common/Cmdlet/EnableAzureStorageStaticWebsite.cs

@@ -27,10 +27,12 @@ namespace Microsoft.WindowsAzure.Commands.Storage.Common.Cmdlet
         OutputType(typeof(PSStaticWebsiteProperties))]
     public class EnableAzureStorageServiceStaticWebsiteCommand : StorageCloudBlobCmdletBase
     {
-        [Parameter(Mandatory = true, Position = 0, HelpMessage = "The name of the index document in each directory.")]
+        [Parameter(Mandatory = false, Position = 0, HelpMessage = "The name of the index document in each directory.")]
+        [ValidateNotNull]
         public string IndexDocument { get; set; }
 
-        [Parameter(Mandatory = true, Position = 1, HelpMessage = "the path to the error document that should be shown when a 404 is issued (meaning, when a browser requests a page that does not exist.)")]
+        [Parameter(Mandatory = false, Position = 1, HelpMessage = "the path to the error document that should be shown when a 404 is issued (meaning, when a browser requests a page that does not exist.)")]
+        [ValidateNotNull]
         public string ErrorDocument404Path { get; set; }
 
         [Parameter(Mandatory = false)]
@@ -57,8 +59,14 @@ internal void EnableStaticWebsiteProperties(ServiceProperties serviceProperties)
                 serviceProperties.StaticWebsite = new StaticWebsiteProperties();
             }
             serviceProperties.StaticWebsite.Enabled = true;
-            serviceProperties.StaticWebsite.IndexDocument = this.IndexDocument;
-            serviceProperties.StaticWebsite.ErrorDocument404Path = this.ErrorDocument404Path;
+            if (this.IndexDocument != null)
+            {
+                serviceProperties.StaticWebsite.IndexDocument = this.IndexDocument;
+            }
+            if (this.ErrorDocument404Path != null)
+            {
+                serviceProperties.StaticWebsite.ErrorDocument404Path = this.ErrorDocument404Path;
+            }
         }
 
         /// <summary>