[ENG] Fix namespace collision between src and generated submodule (#28196)

Author: NoriZC

src/Az.autorest.props

@@ -13,7 +13,6 @@
     <LangVersion>7.1</LangVersion>
     <TargetFramework>netstandard2.0</TargetFramework>
     <AssemblyName>Az.$(PsModuleName).private</AssemblyName>
-    <RootNamespace>$(AzAssemblyPrefix)$(PsModuleName)</RootNamespace>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
     <AppendTargetFrameworkToOutputPath>false</AppendTargetFrameworkToOutputPath>

tools/BuildScripts/BuildScripts.psm1

@@ -178,8 +178,33 @@ function Update-GeneratedSubModule {
     if ($csprojName -match "^Az\.(?<cSubModuleName>\w+)\.csproj$") {
         $cSubModuleNameTrimmed = $Matches["cSubModuleName"]
     }
+    
+    # Get namespace from csproj file
+    $csprojPath = Join-Path $SourceDirectory $csprojName
+    Write-Host "Reading namespace from csproj: $csprojPath" -ForegroundColor DarkGreen
+    $namespace = $null
+    if (Test-Path $csprojPath) {
+        try {
+            [xml]$csprojContent = Get-Content $csprojPath
+            $rootNamespaceNode = $csprojContent.Project.PropertyGroup.RootNamespace
+            if ($rootNamespaceNode) {
+                $namespace = "$rootNamespaceNode".Trim()
+                Write-Host "Loading namespace from csproj: $namespace retrieved" -ForegroundColor Green
+            }
+            else {
+                Write-Warning "RootNamespace not found in csproj file"
+            }
+        }
+        catch {
+            Write-Warning "Failed to read namespace from csproj: $($_.Exception.Message)"
+        }
+    }
+    else {
+        Write-Warning "Csproj file not found at path: $csprojPath"
+    }
+    
     # regenerate csproj
-    New-GeneratedFileFromTemplate -TemplateName 'Az.ModuleName.csproj' -GeneratedFileName $csprojName -GeneratedDirectory $GeneratedDirectory -ModuleRootName $ModuleRootName -SubModuleName $cSubModuleNameTrimmed -SubModuleNameFull $SubModuleName
+    New-GeneratedFileFromTemplate -TemplateName 'Az.ModuleName.csproj' -GeneratedFileName $csprojName -GeneratedDirectory $GeneratedDirectory -ModuleRootName $ModuleRootName -SubModuleName $cSubModuleNameTrimmed -SubModuleNameFull $SubModuleName -Namespace $namespace
 
     # revert guid in psd1 so that no conflict in updating this file
     if ($guid) {
@@ -209,7 +234,9 @@ function New-GeneratedFileFromTemplate {
         [string]
         $SubModuleName,
         [string]
-        $SubModuleNameFull
+        $SubModuleNameFull,
+        [string]
+        $Namespace
     )
     $TemplatePath = Join-Path $PSScriptRoot "Templates"
     $templateFile = Join-Path $TemplatePath $TemplateName
@@ -228,6 +255,9 @@ function New-GeneratedFileFromTemplate {
         $templateFile = $templateFile -replace '{ModuleFolderPlaceHolder}', "$SubModuleName.Autorest"
     }
     $templateFile = $templateFile -replace '{RootModuleNamePlaceHolder}', $ModuleRootName
+    if ($Namespace) {
+        $templateFile = $templateFile -replace '{NamespacePlaceHolder}', $Namespace
+    }
     Write-Host "Copying template: $TemplateName." -ForegroundColor Yellow
     $templateFile | Set-Content $GeneratedFile -force
 }

tools/BuildScripts/Templates/Az.ModuleName.csproj

@@ -3,6 +3,7 @@
     <PsModuleName>{ModuleNamePlaceHolder}</PsModuleName>
     <PsRootModuleName>{RootModuleNamePlaceHolder}</PsRootModuleName>
     <PsModuleFolder>{ModuleFolderPlaceHolder}</PsModuleFolder>
+    <RootNamespace>{NamespacePlaceHolder}</RootNamespace>
   </PropertyGroup>
 
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory).., build.proj))\src\Az.autorest.props" />