fix: Do not warn about empty configs when they aren't really empty

This was caused by a logic error that thought that a file was empty just
because it didn't find any configuration data relevant to the current
subcommand. For example, a config file that only has Radarr config in it
when you run `recyclarr sonarr`.

CHANGELOG.md

@@ -8,6 +8,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- Do not warn about empty configuration YAML files when they aren't really empty.
+
 ## [3.1.0] - 2022-12-10
 
 ### Changed

src/Recyclarr.Tests/Config/ConfigurationLoaderTest.cs

@@ -275,12 +275,37 @@ sonarr:
     }
 
     [Test, AutoMockData]
-    public void Yaml_file_with_only_comment_should_be_skipped(ConfigurationLoader<TestConfig> sut)
+    public void Throw_when_yaml_file_only_has_comment(ConfigurationLoader<TestConfig> sut)
     {
         const string testYml = "# YAML with nothing but this comment";
 
-        var result = sut.LoadFromStream(new StringReader(testYml), "fubar");
+        var act = () => sut.LoadFromStream(new StringReader(testYml), "fubar");
 
-        result.Should().BeEmpty();
+        act.Should().Throw<EmptyYamlException>();
+    }
+
+    [Test, AutoMockData]
+    public void Throw_when_yaml_file_is_empty(ConfigurationLoader<TestConfig> sut)
+    {
+        const string testYml = "";
+
+        var act = () => sut.LoadFromStream(new StringReader(testYml), "fubar");
+
+        act.Should().Throw<EmptyYamlException>();
+    }
+
+    [Test, AutoMockData]
+    public void Do_not_throw_when_file_not_empty_but_has_no_desired_sections(ConfigurationLoader<TestConfig> sut)
+    {
+        const string testYml = @"
+not_wanted:
+  instance:
+    base_url: abc
+    api_key: xyz
+";
+
+        var act = () => sut.LoadFromStream(new StringReader(testYml), "fubar");
+
+        act.Should().NotThrow();
     }
 }

src/Recyclarr/Config/ConfigurationLoader.cs

@@ -45,13 +45,12 @@ public class ConfigurationLoader<T> : IConfigurationLoader<T>
         try
         {
             using var stream = _fs.File.OpenText(file);
-            var configs = LoadFromStream(stream, configSection);
-            if (!configs.Any())
-            {
-                _log.Warning("Configuration file yielded no usable configuration (is it empty?)");
-            }
-
-            return configs;
+            return LoadFromStream(stream, configSection);
+        }
+        catch (EmptyYamlException)
+        {
+            _log.Warning("Configuration file yielded no usable configuration (is it empty?)");
+            return Array.Empty<T>();
         }
         catch (YamlException e)
         {
@@ -81,14 +80,14 @@ public class ConfigurationLoader<T> : IConfigurationLoader<T>
         if (parser.Current is StreamEnd)
         {
             _log.Debug("Skipping this config due to StreamEnd");
-            return Array.Empty<T>();
+            throw new EmptyYamlException();
         }
 
         parser.Consume<DocumentStart>();
         if (parser.Current is DocumentEnd)
         {
             _log.Debug("Skipping this config due to DocumentEnd");
-            return Array.Empty<T>();
+            throw new EmptyYamlException();
         }
 
         return ParseAllSections(parser, requestedSection);

src/Recyclarr/Config/EmptyYamlException.cs

@@ -0,0 +1,5 @@
+namespace Recyclarr.Config;
+
+public class EmptyYamlException : Exception
+{
+}