From 96fad764416360f83fefb791c684a49f9765d412 Mon Sep 17 00:00:00 2001
From: "Brett V. Forsgren" <brettfo@microsoft.com>
Date: Fri, 21 Feb 2025 14:33:10 -0700
Subject: [PATCH] ensure proper casing for `NuGet.Config` prior to any
 operations being performed

---
 nuget/lib/dependabot/nuget/file_fetcher.rb      |  1 +
 nuget/lib/dependabot/nuget/native_helpers.rb    | 16 ++++++++++++++++
 .../spec/dependabot/nuget/file_fetcher_spec.rb  |  2 ++
 nuget/updater/common.ps1                        | 17 +++++++++++++++++
 nuget/updater/main.ps1                          |  1 +
 nuget/updater/normalize-file-names.ps1          | 14 ++++++++++++++
 6 files changed, 51 insertions(+)
 create mode 100755 nuget/updater/normalize-file-names.ps1

diff --git a/nuget/lib/dependabot/nuget/file_fetcher.rb b/nuget/lib/dependabot/nuget/file_fetcher.rb
index 5888dc44c32..8b21ebdce54 100644
--- a/nuget/lib/dependabot/nuget/file_fetcher.rb
+++ b/nuget/lib/dependabot/nuget/file_fetcher.rb
@@ -26,6 +26,7 @@ def self.required_files_message
 
       sig { override.returns(T::Array[DependencyFile]) }
       def fetch_files
+        NativeHelpers.normalize_file_names
         NativeHelpers.install_dotnet_sdks
         discovery_json_reader = DiscoveryJsonReader.run_discovery_in_directory(
           repo_contents_path: T.must(repo_contents_path),
diff --git a/nuget/lib/dependabot/nuget/native_helpers.rb b/nuget/lib/dependabot/nuget/native_helpers.rb
index a59c1399b15..57615697fe8 100644
--- a/nuget/lib/dependabot/nuget/native_helpers.rb
+++ b/nuget/lib/dependabot/nuget/native_helpers.rb
@@ -286,6 +286,22 @@ def self.run_nuget_updater_tool(job_path:, repo_root:, proj_path:, dependency:,
         end
       end
 
+      sig { void }
+      def self.normalize_file_names
+        # environment variables are required and the following will generate an actionable error message if they're not
+        _dependabot_repo_contents_path = ENV.fetch("DEPENDABOT_REPO_CONTENTS_PATH")
+
+        # this environment variable is directly used
+        dependabot_home = ENV.fetch("DEPENDABOT_HOME")
+
+        command = [
+          "pwsh",
+          "#{dependabot_home}/dependabot-updater/bin/normalize-file-names.ps1"
+        ].join(" ")
+        output = SharedHelpers.run_shell_command(command)
+        puts output
+      end
+
       sig { void }
       def self.install_dotnet_sdks
         return unless Dependabot::Experiments.enabled?(:nuget_install_dotnet_sdks)
diff --git a/nuget/spec/dependabot/nuget/file_fetcher_spec.rb b/nuget/spec/dependabot/nuget/file_fetcher_spec.rb
index e56c04e589b..ae684eb47ee 100644
--- a/nuget/spec/dependabot/nuget/file_fetcher_spec.rb
+++ b/nuget/spec/dependabot/nuget/file_fetcher_spec.rb
@@ -72,6 +72,8 @@ def run_fetch_test(files_on_disk:, discovery_content_hash:, &_block)
           discovery_json_content = discovery_content_hash.to_json
           File.write(discovery_json_path, discovery_json_content)
         end
+      allow(Dependabot::Nuget::NativeHelpers)
+        .to receive(:normalize_file_names)
       # stub call to `fetch_file_from_host` because it expects an empty directory and other things that make the test
       # more difficult than it needs to be
       allow(file_fetcher_instance)
diff --git a/nuget/updater/common.ps1 b/nuget/updater/common.ps1
index fadc1f0ec80..02f163167a4 100755
--- a/nuget/updater/common.ps1
+++ b/nuget/updater/common.ps1
@@ -134,3 +134,20 @@ function Install-TargetingPacks([string]$sdkInstallDir, [string[]]$targetingPack
         Remove-Item -Path $archiveName
     }
 }
+
+function Repair-FileCasingForName([string]$fileName) {
+    # Get-ChildItem is case-insensitive
+    $discoveredFiles = Get-ChildItem $env:DEPENDABOT_REPO_CONTENTS_PATH -r -inc $fileName
+    foreach ($file in $discoveredFiles) {
+        # `-cne` = Case-sensitive Not Equal
+        if ($file.Name -cne $fileName) {
+            $newName = "$($file.Directory)/$fileName"
+            Write-Host "Renaming '$file' to '$newName'"
+            Rename-Item -Path $file -NewName $newName
+        }
+    }
+}
+
+function Repair-FileCasing() {
+    Repair-FileCasingForName -fileName "NuGet.Config"
+}
diff --git a/nuget/updater/main.ps1 b/nuget/updater/main.ps1
index 49fd2bc94e7..4cdeeef59b1 100644
--- a/nuget/updater/main.ps1
+++ b/nuget/updater/main.ps1
@@ -21,6 +21,7 @@ function Get-Files {
         --api-url $env:DEPENDABOT_API_URL `
         --job-id $env:DEPENDABOT_JOB_ID
     $script:operationExitCode = $LASTEXITCODE
+    Repair-FileCasing
 }
 
 function Update-Files {
diff --git a/nuget/updater/normalize-file-names.ps1 b/nuget/updater/normalize-file-names.ps1
new file mode 100755
index 00000000000..1138e9a3a9f
--- /dev/null
+++ b/nuget/updater/normalize-file-names.ps1
@@ -0,0 +1,14 @@
+Set-StrictMode -version 2.0
+$ErrorActionPreference = "Stop"
+
+. $PSScriptRoot\common.ps1
+
+try {
+    Repair-FileCasing
+}
+catch {
+    Write-Host $_
+    Write-Host $_.Exception
+    Write-Host $_.ScriptStackTrace
+    exit 1
+}