fix: Do not assume only one field element in CF specifications

For most CF specifications, there is only one element in the `fields`
array, which has a `value` property inside of each of its objects. One
particular specification, however, deviates from this assumption. The
"SizeSpecification" has been observed with *two* field objects.

Logic for parsing custom format CFs no longer assumes that the fields
property may only have one element in it.

Fixes #178

CHANGELOG.md

@@ -8,6 +8,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed JSON parsing issue that sometimes occurs when pulling custom formats from Radarr (#178)
+
 ## [4.4.0] - 2023-04-06
 
 ### Added

src/Recyclarr.TrashLib.Tests/Pipelines/CustomFormat/Api/CustomFormatServiceTest.cs

@@ -0,0 +1,27 @@
+using Flurl.Http.Testing;
+using Recyclarr.Cli.TestLibrary;
+using Recyclarr.Common;
+using Recyclarr.TrashLib.Config.Services;
+using Recyclarr.TrashLib.Pipelines.CustomFormat.Api;
+
+namespace Recyclarr.TrashLib.Tests.Pipelines.CustomFormat.Api;
+
+[TestFixture]
+[Parallelizable(ParallelScope.All)]
+public class CustomFormatServiceTest : IntegrationFixture
+{
+    [Test, AutoMockData]
+    public async Task Get_can_parse_json(IServiceConfiguration config)
+    {
+        var resourceData = new ResourceDataReader(typeof(CustomFormatServiceTest), "Data");
+        var jsonBody = resourceData.ReadData("issue_178.json");
+
+        using var http = new HttpTest();
+        http.RespondWith(jsonBody);
+
+        var sut = Resolve<CustomFormatService>();
+        var result = await sut.GetCustomFormats(config);
+
+        result.Should().HaveCountGreaterThan(5);
+    }
+}

src/Recyclarr.TrashLib.Tests/Pipelines/CustomFormat/Guide/CustomFormatParserTest.cs

@@ -66,9 +66,12 @@ public class CustomFormatParserTest
                     Implementation = "ReleaseTitleSpecification",
                     Negate = false,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = "\\bEVO(TGX)?\\b"
+                        new CustomFormatFieldData
+                        {
+                            Value = "\\bEVO(TGX)?\\b"
+                        }
                     }
                 },
                 new CustomFormatSpecificationData
@@ -77,9 +80,12 @@ public class CustomFormatParserTest
                     Implementation = "SourceSpecification",
                     Negate = true,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = 7
+                        new CustomFormatFieldData
+                        {
+                            Value = 7
+                        }
                     }
                 },
                 new CustomFormatSpecificationData
@@ -88,9 +94,12 @@ public class CustomFormatParserTest
                     Implementation = "SourceSpecification",
                     Negate = true,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = 8
+                        new CustomFormatFieldData
+                        {
+                            Value = 8
+                        }
                     }
                 }
             }

src/Recyclarr.TrashLib.Tests/Pipelines/CustomFormat/Models/CustomFormatDataComparerTest.cs

@@ -21,9 +21,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "ReleaseTitleSpecification",
                     Negate = false,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = "\\bEVO(TGX)?\\b"
+                        new CustomFormatFieldData
+                        {
+                            Value = "\\bEVO(TGX)?\\b"
+                        }
                     }
                 },
                 new CustomFormatSpecificationData
@@ -32,9 +35,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "SourceSpecification",
                     Negate = true,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = 7
+                        new CustomFormatFieldData
+                        {
+                            Value = 7
+                        }
                     }
                 },
                 new CustomFormatSpecificationData
@@ -43,9 +49,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "SourceSpecification",
                     Negate = true,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = 8
+                        new CustomFormatFieldData
+                        {
+                            Value = 8
+                        }
                     }
                 }
             }
@@ -63,9 +72,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "ReleaseTitleSpecification",
                     Negate = false,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = "\\bEVO(TGX)?\\b"
+                        new CustomFormatFieldData
+                        {
+                            Value = "\\bEVO(TGX)?\\b"
+                        }
                     }
                 },
                 new CustomFormatSpecificationData
@@ -74,9 +86,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "SourceSpecification",
                     Negate = true,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = 7
+                        new CustomFormatFieldData
+                        {
+                            Value = 7
+                        }
                     }
                 },
                 new CustomFormatSpecificationData
@@ -85,17 +100,18 @@ public class CustomFormatDataComparerTest
                     Implementation = "SourceSpecification",
                     Negate = true,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = 8
+                        new CustomFormatFieldData
+                        {
+                            Value = 8
+                        }
                     }
                 }
             }
         };
 
-        var result = CustomFormatData.Comparer.Equals(a, b);
-
-        result.Should().BeTrue();
+        a.Should().BeEquivalentTo(b, o => o.Using(CustomFormatData.Comparer));
     }
 
     [Test]
@@ -113,9 +129,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "ReleaseTitleSpecification",
                     Negate = false,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = "\\bEVO(TGX)?\\b"
+                        new CustomFormatFieldData
+                        {
+                            Value = "\\bEVO(TGX)?\\b"
+                        }
                     }
                 },
                 new CustomFormatSpecificationData
@@ -124,9 +143,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "SourceSpecification",
                     Negate = true,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = 7
+                        new CustomFormatFieldData
+                        {
+                            Value = 7
+                        }
                     }
                 },
                 new CustomFormatSpecificationData
@@ -135,9 +157,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "SourceSpecification",
                     Negate = true,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = 8
+                        new CustomFormatFieldData
+                        {
+                            Value = 8
+                        }
                     }
                 }
             }
@@ -155,9 +180,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "ReleaseTitleSpecification",
                     Negate = false,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = "\\bEVO(TGX)?\\b"
+                        new CustomFormatFieldData
+                        {
+                            Value = "\\bEVO(TGX)?\\b"
+                        }
                     }
                 },
                 new CustomFormatSpecificationData
@@ -166,9 +194,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "SourceSpecification",
                     Negate = true,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = 10 // this is different
+                        new CustomFormatFieldData
+                        {
+                            Value = 10 // this is different
+                        }
                     }
                 },
                 new CustomFormatSpecificationData
@@ -177,9 +208,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "SourceSpecification",
                     Negate = true,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = 8
+                        new CustomFormatFieldData
+                        {
+                            Value = 8
+                        }
                     }
                 }
             }
@@ -292,9 +326,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "ReleaseTitleSpecification",
                     Negate = false,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = "\\bEVO(TGX)?\\b"
+                        new CustomFormatFieldData
+                        {
+                            Value = "\\bEVO(TGX)?\\b"
+                        }
                     }
                 },
                 new CustomFormatSpecificationData
@@ -303,9 +340,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "SourceSpecification",
                     Negate = true,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = 7
+                        new CustomFormatFieldData
+                        {
+                            Value = 7
+                        }
                     }
                 },
                 new CustomFormatSpecificationData
@@ -314,9 +354,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "SourceSpecification",
                     Negate = true,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = 8
+                        new CustomFormatFieldData
+                        {
+                            Value = 8
+                        }
                     }
                 }
             }
@@ -334,9 +377,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "ReleaseTitleSpecification",
                     Negate = false,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = "\\bEVO(TGX)?\\b"
+                        new CustomFormatFieldData
+                        {
+                            Value = "\\bEVO(TGX)?\\b"
+                        }
                     }
                 },
                 new CustomFormatSpecificationData
@@ -345,9 +391,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "SourceSpecification",
                     Negate = true,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = 7
+                        new CustomFormatFieldData
+                        {
+                            Value = 7
+                        }
                     }
                 },
                 new CustomFormatSpecificationData
@@ -356,9 +405,12 @@ public class CustomFormatDataComparerTest
                     Implementation = "SourceSpecification",
                     Negate = true,
                     Required = true,
-                    Fields = new CustomFormatFieldData
+                    Fields = new[]
                     {
-                        Value = 8
+                        new CustomFormatFieldData
+                        {
+                            Value = 8
+                        }
                     }
                 }
             }

src/Recyclarr.TrashLib.Tests/Pipelines/CustomFormat/Models/FieldsArrayJsonConverterTest.cs

@@ -0,0 +1,101 @@
+using Flurl.Http.Configuration;
+using Recyclarr.TrashLib.Json;
+using Recyclarr.TrashLib.Pipelines.CustomFormat.Models;
+
+namespace Recyclarr.TrashLib.Tests.Pipelines.CustomFormat.Models;
+
+[TestFixture]
+[Parallelizable(ParallelScope.All)]
+public class FieldsArrayJsonConverterTest
+{
+    [Test]
+    public void Read_multiple_as_array()
+    {
+        var serializer = new NewtonsoftJsonSerializer(ServiceJsonSerializerFactory.Settings);
+
+        const string json = @"
+{
+  'fields': [
+    {
+      'order': 0,
+      'name': 'min',
+      'label': 'Minimum Size',
+      'unit': 'GB',
+      'helpText': 'Release must be greater than this size',
+      'value': 25,
+      'type': 'number',
+      'advanced': false
+    },
+    {
+      'order': 1,
+      'name': 'max',
+      'label': 'Maximum Size',
+      'unit': 'GB',
+      'helpText': 'Release must be less than or equal to this size',
+      'value': 40,
+      'type': 'number',
+      'advanced': false
+    }
+  ]
+}
+";
+        var result = serializer.Deserialize<CustomFormatSpecificationData>(json);
+
+        result.Fields.Should().BeEquivalentTo(new[]
+        {
+            new CustomFormatFieldData
+            {
+                Value = 25
+            },
+            new CustomFormatFieldData
+            {
+                Value = 40
+            }
+        });
+    }
+
+    [Test]
+    public void Read_single_as_array()
+    {
+        var serializer = new NewtonsoftJsonSerializer(ServiceJsonSerializerFactory.Settings);
+
+        const string json = @"
+{
+  'fields': {
+    'order': 0,
+    'name': 'min',
+    'label': 'Minimum Size',
+    'unit': 'GB',
+    'helpText': 'Release must be greater than this size',
+    'value': 25,
+    'type': 'number',
+    'advanced': false
+  }
+}
+";
+        var result = serializer.Deserialize<CustomFormatSpecificationData>(json);
+
+        result.Fields.Should().BeEquivalentTo(new[]
+        {
+            new CustomFormatFieldData
+            {
+                Value = 25
+            }
+        });
+    }
+
+    [Test]
+    public void Read_throws_on_unsupported_token_type()
+    {
+        var serializer = new NewtonsoftJsonSerializer(ServiceJsonSerializerFactory.Settings);
+
+        const string json = @"
+{
+  'fields': 0
+}
+";
+        var act = () => serializer.Deserialize<CustomFormatSpecificationData>(json);
+
+        act.Should().Throw<InvalidOperationException>();
+    }
+}

src/Recyclarr.TrashLib/Pipelines/CustomFormat/Api/CustomFormatService.cs

@@ -5,7 +5,7 @@ using Recyclarr.TrashLib.Pipelines.CustomFormat.Models;
 
 namespace Recyclarr.TrashLib.Pipelines.CustomFormat.Api;
 
-internal class CustomFormatService : ICustomFormatService
+public class CustomFormatService : ICustomFormatService
 {
     private readonly IServiceRequestBuilder _service;
 

src/Recyclarr.TrashLib/Pipelines/CustomFormat/Models/CustomFormatData.cs

@@ -19,7 +19,7 @@ public record CustomFormatSpecificationData
     public bool Required { get; init; }
 
     [JsonConverter(typeof(FieldsArrayJsonConverter))]
-    public CustomFormatFieldData Fields { get; init; } = new();
+    public IReadOnlyCollection<CustomFormatFieldData> Fields { get; init; } = Array.Empty<CustomFormatFieldData>();
 }
 
 public record CustomFormatData

src/Recyclarr.TrashLib/Pipelines/CustomFormat/Models/CustomFormatDataComparer.cs

@@ -39,10 +39,29 @@ public sealed class CustomFormatDataEqualityComparer : IEqualityComparer<CustomF
     private static bool SpecificationEqual(CustomFormatSpecificationData a, CustomFormatSpecificationData b)
     {
         return a.Name.Equals(b.Name, StringComparison.Ordinal) &&
-            Equals(a.Fields.Value, b.Fields.Value) &&
             a.Implementation.Equals(b.Implementation, StringComparison.Ordinal) &&
             a.Negate.Equals(b.Negate) &&
-            a.Required.Equals(b.Required);
+            a.Required.Equals(b.Required) &&
+            AllFieldsEqual(a.Fields, b.Fields);
+    }
+
+    private static bool AllFieldsEqual(
+        IReadOnlyCollection<CustomFormatFieldData> first,
+        IReadOnlyCollection<CustomFormatFieldData> second)
+    {
+        if (first.Count != second.Count)
+        {
+            return false;
+        }
+
+        return first
+            .FullJoin(second, x => x.Name, _ => false, _ => false, FieldEqual)
+            .All(x => x);
+    }
+
+    private static bool FieldEqual(CustomFormatFieldData a, CustomFormatFieldData b)
+    {
+        return a.Value?.Equals(b.Value) ?? false;
     }
 
     public int GetHashCode(CustomFormatData obj)

src/Recyclarr.TrashLib/Pipelines/CustomFormat/Models/FieldsArrayJsonConverter.cs

@@ -7,22 +7,7 @@ public class FieldsArrayJsonConverter : JsonConverter
 {
     public override void WriteJson(JsonWriter writer, object? value, JsonSerializer serializer)
     {
-        if (value is not CustomFormatFieldData)
-        {
-            serializer.Serialize(writer, value);
-            return;
-        }
-
-        var token = JToken.FromObject(value);
-        if (token.Type == JTokenType.Object)
-        {
-            var array = new JArray(token);
-            serializer.Serialize(writer, array);
-        }
-        else
-        {
-            serializer.Serialize(writer, token);
-        }
+        serializer.Serialize(writer, value);
     }
 
     public override object? ReadJson(
@@ -31,17 +16,14 @@ public class FieldsArrayJsonConverter : JsonConverter
         object? existingValue,
         JsonSerializer serializer)
     {
-        if (existingValue is not CustomFormatFieldData)
-        {
-            return new CustomFormatFieldData();
-        }
-
         var token = JToken.Load(reader);
+
+        // ReSharper disable once SwitchExpressionHandlesSomeKnownEnumValuesWithExceptionInDefault
         return token.Type switch
         {
-            JTokenType.Object => token.ToObject<CustomFormatFieldData>(),
-            JTokenType.Array => token.ToObject<CustomFormatFieldData[]>()?.SingleOrDefault(),
-            _ => null
+            JTokenType.Object => new[] {token.ToObject<CustomFormatFieldData>()},
+            JTokenType.Array => token.ToObject<CustomFormatFieldData[]>(),
+            _ => throw new InvalidOperationException("Unsupported token type for CustomFormatFieldData")
         };
     }