Add tests for NoralizeLanguage

Jellyfin.sln

@@ -81,6 +81,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Jellyfin.Server.Tests", "te
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Jellyfin.Server.Integration.Tests", "tests\Jellyfin.Server.Integration.Tests\Jellyfin.Server.Integration.Tests.csproj", "{68B0B823-A5AC-4E8B-82EA-965AAC7BF76E}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Jellyfin.Providers.Tests", "tests\Jellyfin.Providers.Tests\Jellyfin.Providers.Tests.csproj", "{CE21845F-74AD-42F6-B7BA-90506E6CD09E}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -223,6 +225,10 @@ Global
 		{68B0B823-A5AC-4E8B-82EA-965AAC7BF76E}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{68B0B823-A5AC-4E8B-82EA-965AAC7BF76E}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{68B0B823-A5AC-4E8B-82EA-965AAC7BF76E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{CE21845F-74AD-42F6-B7BA-90506E6CD09E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{CE21845F-74AD-42F6-B7BA-90506E6CD09E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{CE21845F-74AD-42F6-B7BA-90506E6CD09E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{CE21845F-74AD-42F6-B7BA-90506E6CD09E}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -240,6 +246,7 @@ Global
 		{42816EA8-4511-4CBF-A9C7-7791D5DDDAE6} = {FBBB5129-006E-4AD7-BAD5-8B7CA1D10ED6}
 		{3ADBCD8C-C0F2-4956-8FDC-35D686B74CF9} = {FBBB5129-006E-4AD7-BAD5-8B7CA1D10ED6}
 		{68B0B823-A5AC-4E8B-82EA-965AAC7BF76E} = {FBBB5129-006E-4AD7-BAD5-8B7CA1D10ED6}
+		{CE21845F-74AD-42F6-B7BA-90506E6CD09E} = {FBBB5129-006E-4AD7-BAD5-8B7CA1D10ED6}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {3448830C-EBDC-426C-85CD-7BBB9651A7FE}

MediaBrowser.Providers/Plugins/Tmdb/People/TmdbPersonImageProvider.cs

@@ -47,8 +47,8 @@ namespace MediaBrowser.Providers.Plugins.Tmdb.People
 
         public async Task<IEnumerable<RemoteImageInfo>> GetImages(BaseItem item, CancellationToken cancellationToken)
         {
-            var language = item.GetPreferredMetadataLanguage();
             var person = (Person)item;
+            var language = item.GetPreferredMetadataLanguage();
 
             if (!person.TryGetProviderId(MetadataProvider.Tmdb, out var personTmdbId))
             {

MediaBrowser.Providers/Plugins/Tmdb/TmdbUtils.cs

@@ -149,7 +149,7 @@ namespace MediaBrowser.Providers.Plugins.Tmdb
             if (parts.Length == 2)
             {
                 // TMDB doesn't support Switzerland (de-CH, it-CH or fr-CH) so use the language (de, it or fr) without country code
-                if (string.Equals(parts[1], "ch", StringComparison.Ordinal))
+                if (string.Equals(parts[1], "CH", StringComparison.OrdinalIgnoreCase))
                 {
                     return parts[0];
                 }

tests/Jellyfin.Providers.Tests/Jellyfin.Providers.Tests.csproj

@@ -0,0 +1,30 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net5.0</TargetFramework>
+    <IsPackable>false</IsPackable>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+    <Nullable>enable</Nullable>
+    <AnalysisMode>AllEnabledByDefault</AnalysisMode>
+    <CodeAnalysisRuleSet>../jellyfin-tests.ruleset</CodeAnalysisRuleSet>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.9.4" />
+    <PackageReference Include="xunit" Version="2.4.1" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3" />
+    <PackageReference Include="coverlet.collector" Version="3.0.3" />
+  </ItemGroup>
+
+  <!-- Code Analyzers -->
+  <ItemGroup Condition=" '$(Configuration)' == 'Debug' ">
+    <PackageReference Include="SerilogAnalyzer" Version="0.15.0" PrivateAssets="All" />
+    <PackageReference Include="StyleCop.Analyzers" Version="1.1.118" PrivateAssets="All" />
+    <PackageReference Include="SmartAnalyzers.MultithreadingAnalyzer" Version="1.1.31" PrivateAssets="All" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="../../MediaBrowser.Providers/MediaBrowser.Providers.csproj" />
+  </ItemGroup>
+
+</Project>

tests/Jellyfin.Providers.Tests/Tmdb/TmdbUtilsTests.cs

@@ -0,0 +1,27 @@
+using MediaBrowser.Providers.Plugins.Tmdb;
+using Xunit;
+
+namespace Jellyfin.Providers.Tests.Tmdb
+{
+    public static class TmdbUtilsTests
+    {
+        [Theory]
+        [InlineData("de", "de")]
+        [InlineData("En", "En")]
+        [InlineData("de-de", "de-DE")]
+        [InlineData("en-US", "en-US")]
+        [InlineData("de-CH", "de")]
+        public static void NormalizeLanguage_Valid_Success(string input, string expected)
+        {
+            Assert.Equal(expected, TmdbUtils.NormalizeLanguage(input));
+        }
+
+        [Theory]
+        [InlineData(null, null)]
+        [InlineData("", "")]
+        public static void NormalizeLanguage_Invalid_Equal(string? input, string? expected)
+        {
+            Assert.Equal(expected, TmdbUtils.NormalizeLanguage(input!));
+        }
+    }
+}