Revert "Remove CouldNotFindResourceDictionaries diagnostic"

This reverts commit 43d8fe1.

Author: Jack251970

Flow.Launcher.Localization.SourceGenerators/AnalyzerReleases.Unshipped.md

@@ -4,9 +4,10 @@
 
 Rule ID | Category | Severity | Notes
 --------|----------|----------|-------
-FLSG0001 | Localization | Warning | FLSG0001_LocalizationKeyUnused
+FLSG0001 | Localization | Warning | FLSG0001_CouldNotFindResourceDictionaries
 FLSG0002 | Localization | Warning | FLSG0002_CouldNotFindPluginEntryClass
 FLSG0003 | Localization | Warning | FLSG0003_CouldNotFindContextProperty
 FLSG0004 | Localization | Warning | FLSG0004_ContextPropertyNotStatic
 FLSG0005 | Localization | Warning | FLSG0005_ContextPropertyIsPrivate
 FLSG0006 | Localization | Warning | FLSG0006_ContextPropertyIsProtected
+FLSG0007 | Localization | Warning | FLSG0007_LocalizationKeyUnused

Flow.Launcher.Localization.SourceGenerators/Localize/LocalizeSourceGenerator.cs

@@ -84,6 +84,15 @@ private void Execute(SourceProductionContext spc,
             ImmutableArray<AdditionalText> AdditionalTexts) data)
         {
             var xamlFiles = data.AdditionalTexts;
+            if (xamlFiles.Length == 0)
+            {
+                spc.ReportDiagnostic(Diagnostic.Create(
+                    SourceGeneratorDiagnostics.CouldNotFindResourceDictionaries,
+                    Location.None
+                ));
+                return;
+            }
+
             var compilation = data.Item1.Compilation;
             var configOptions = data.Item1.Item1.ConfigOptionsProvider;
             var pluginClasses = data.Item1.Item1.Item1.PluginClassInfos;

Flow.Launcher.Localization.SourceGenerators/SourceGeneratorDiagnostics.cs

@@ -5,10 +5,10 @@ namespace Flow.Launcher.Localization.SourceGenerators
 {
     public static class SourceGeneratorDiagnostics
     {
-        public static readonly DiagnosticDescriptor LocalizationKeyUnused = new DiagnosticDescriptor(
+        public static readonly DiagnosticDescriptor CouldNotFindResourceDictionaries = new DiagnosticDescriptor(
             "FLSG0001",
-            "Localization key is unused",
-            $"Method `{Constants.ClassName}.{{0}}` is never used",
+            "Could not find resource dictionaries",
+            "Could not find resource dictionaries. There must be a file named [LANG].xaml file (for example, en.xaml), and it must be specified in <AdditionalFiles /> in your .csproj file.",
             "Localization",
             DiagnosticSeverity.Warning,
             isEnabledByDefault: true
@@ -58,5 +58,14 @@ public static class SourceGeneratorDiagnostics
             DiagnosticSeverity.Warning,
             isEnabledByDefault: true
         );
+
+        public static readonly DiagnosticDescriptor LocalizationKeyUnused = new DiagnosticDescriptor(
+            "FLSG0007",
+            "Localization key is unused",
+            $"Method `{Constants.ClassName}.{{0}}` is never used",
+            "Localization",
+            DiagnosticSeverity.Warning,
+            isEnabledByDefault: true
+        );
     }
 }