From 76e640b0b9f46ed82433da9cb8f8c27aa5889743 Mon Sep 17 00:00:00 2001
From: Joe Rogers <1337joe@gmail.com>
Date: Tue, 28 Dec 2021 15:10:41 +0100
Subject: [PATCH] Add tests and documentation for ProviderUtils

---
 .../Manager/ProviderUtils.cs                  |  17 +-
 .../Manager/ProviderUtilsTests.cs             | 375 ++++++++++++++++++
 2 files changed, 389 insertions(+), 3 deletions(-)
 create mode 100644 tests/Jellyfin.Providers.Tests/Manager/ProviderUtilsTests.cs

diff --git a/MediaBrowser.Providers/Manager/ProviderUtils.cs b/MediaBrowser.Providers/Manager/ProviderUtils.cs
index b90136d509..798fd0d681 100644
--- a/MediaBrowser.Providers/Manager/ProviderUtils.cs
+++ b/MediaBrowser.Providers/Manager/ProviderUtils.cs
@@ -1,7 +1,5 @@
 #nullable disable
 
-#pragma warning disable CS1591
-
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -13,8 +11,21 @@ using MediaBrowser.Model.Entities;
 
 namespace MediaBrowser.Providers.Manager
 {
+    /// <summary>
+    /// Class ProviderUtils.
+    /// </summary>
     public static class ProviderUtils
     {
+        /// <summary>
+        /// Merges metadata from source into target.
+        /// </summary>
+        /// <param name="sourceResult">The source for new metadata.</param>
+        /// <param name="targetResult">The target to insert new metadata into.</param>
+        /// <param name="lockedFields">The fields that are locked and should not be updated.</param>
+        /// <param name="replaceData"><c>true</c> if existing data should be replaced.</param>
+        /// <param name="mergeMetadataSettings"><c>true</c> if the metadata settings in target should be updated to match source.</param>
+        /// <typeparam name="T">The type being acted upon.</typeparam>
+        /// <exception cref="ArgumentException">Thrown if source or target are null.</exception>
         public static void MergeBaseItemData<T>(
             MetadataResult<T> sourceResult,
             MetadataResult<T> targetResult,
@@ -200,7 +211,7 @@ namespace MediaBrowser.Providers.Manager
                 target.LockedFields = source.LockedFields;
                 target.IsLocked = source.IsLocked;
 
-                // Grab the value if it's there, but if not then don't overwrite the default
+                // Grab the value if it's there, but if not then don't overwrite with the default
                 if (source.DateCreated != default)
                 {
                     target.DateCreated = source.DateCreated;
diff --git a/tests/Jellyfin.Providers.Tests/Manager/ProviderUtilsTests.cs b/tests/Jellyfin.Providers.Tests/Manager/ProviderUtilsTests.cs
new file mode 100644
index 0000000000..9e4bbef136
--- /dev/null
+++ b/tests/Jellyfin.Providers.Tests/Manager/ProviderUtilsTests.cs
@@ -0,0 +1,375 @@
+using System;
+using System.Collections.Generic;
+using MediaBrowser.Controller.Entities;
+using MediaBrowser.Controller.Entities.Audio;
+using MediaBrowser.Controller.Entities.Movies;
+using MediaBrowser.Controller.Entities.TV;
+using MediaBrowser.Controller.Providers;
+using MediaBrowser.Model.Entities;
+using MediaBrowser.Providers.Manager;
+using Xunit;
+
+namespace Jellyfin.Providers.Tests.Manager
+{
+    public class ProviderUtilsTests
+    {
+        [Theory]
+        [InlineData(false, false)]
+        [InlineData(true, false)]
+        [InlineData(true, true)]
+        public void MergeBaseItemData_MergeMetadataSettings_MergesWhenSet(bool mergeMetadataSettings, bool defaultDate)
+        {
+            var newLocked = new[] { MetadataField.Cast };
+            var newString = "new";
+            var newDate = DateTime.Now;
+
+            var oldLocked = new[] { MetadataField.Genres };
+            var oldString = "old";
+            var oldDate = DateTime.UnixEpoch;
+
+            var source = new MetadataResult<Movie>
+            {
+                Item = new Movie
+                {
+                    LockedFields = newLocked,
+                    IsLocked = true,
+                    PreferredMetadataCountryCode = newString,
+                    PreferredMetadataLanguage = newString,
+                    DateCreated = newDate
+                }
+            };
+            if (defaultDate)
+            {
+                source.Item.DateCreated = default;
+            }
+
+            var target = new MetadataResult<Movie>
+            {
+                Item = new Movie
+                {
+                    LockedFields = oldLocked,
+                    IsLocked = false,
+                    PreferredMetadataCountryCode = oldString,
+                    PreferredMetadataLanguage = oldString,
+                    DateCreated = oldDate
+                }
+            };
+
+            ProviderUtils.MergeBaseItemData(source, target, Array.Empty<MetadataField>(), true, mergeMetadataSettings);
+
+            if (mergeMetadataSettings)
+            {
+                Assert.Equal(newLocked, target.Item.LockedFields);
+                Assert.True(target.Item.IsLocked);
+                Assert.Equal(newString, target.Item.PreferredMetadataCountryCode);
+                Assert.Equal(newString, target.Item.PreferredMetadataLanguage);
+                Assert.Equal(defaultDate ? oldDate : newDate, target.Item.DateCreated);
+            }
+            else
+            {
+                Assert.Equal(oldLocked, target.Item.LockedFields);
+                Assert.False(target.Item.IsLocked);
+                Assert.Equal(oldString, target.Item.PreferredMetadataCountryCode);
+                Assert.Equal(oldString, target.Item.PreferredMetadataLanguage);
+                Assert.Equal(oldDate, target.Item.DateCreated);
+            }
+        }
+
+        [Theory]
+        [InlineData("Name", MetadataField.Name, false)]
+        [InlineData("OriginalTitle", null, false)]
+        [InlineData("OfficialRating", MetadataField.OfficialRating)]
+        [InlineData("CustomRating")]
+        [InlineData("Tagline")]
+        [InlineData("Overview", MetadataField.Overview)]
+        [InlineData("DisplayOrder", null, false)]
+        [InlineData("ForcedSortName", null, false)]
+        public void MergeBaseItemData_StringField_ReplacesAppropriately(string propName, MetadataField? lockField = null, bool replacesWithEmpty = true)
+        {
+            var oldValue = "Old";
+            var newValue = "New";
+
+            // Use type Series to hit DisplayOrder
+            Assert.False(TestMergeBaseItemData<Series>(propName, oldValue, newValue, null, false, out _));
+            if (lockField != null)
+            {
+                Assert.False(TestMergeBaseItemData<Series>(propName, oldValue, newValue, lockField, true, out _));
+                Assert.False(TestMergeBaseItemData<Series>(propName, null, newValue, lockField, false, out _));
+                Assert.False(TestMergeBaseItemData<Series>(propName, string.Empty, newValue, lockField, false, out _));
+            }
+
+            Assert.True(TestMergeBaseItemData<Series>(propName, oldValue, newValue, null, true, out _));
+            Assert.True(TestMergeBaseItemData<Series>(propName, null, newValue, null, false, out _));
+            Assert.True(TestMergeBaseItemData<Series>(propName, string.Empty, newValue, null, false, out _));
+
+            var replacedWithEmpty = TestMergeBaseItemData<Series>(propName, oldValue, string.Empty, null, true, out _);
+            Assert.Equal(replacesWithEmpty, replacedWithEmpty);
+        }
+
+        [Theory]
+        [InlineData("Genres", MetadataField.Genres)]
+        [InlineData("Studios", MetadataField.Studios)]
+        [InlineData("Tags", MetadataField.Tags)]
+        [InlineData("ProductionLocations", MetadataField.ProductionLocations)]
+        [InlineData("AlbumArtists")]
+        public void MergeBaseItemData_StringArrayField_ReplacesAppropriately(string propName, MetadataField? lockField = null)
+        {
+            // Note that arrays are replaced, not merged
+            var oldValue = new[] { "Old" };
+            var newValue = new[] { "New" };
+
+            // Use type Audio to hit AlbumArtists
+            Assert.False(TestMergeBaseItemData<Audio>(propName, oldValue, newValue, null, false, out _));
+            if (lockField != null)
+            {
+                Assert.False(TestMergeBaseItemData<Audio>(propName, oldValue, newValue, lockField, true, out _));
+                Assert.False(TestMergeBaseItemData<Audio>(propName, Array.Empty<string>(), newValue, lockField, false, out _));
+            }
+
+            Assert.True(TestMergeBaseItemData<Audio>(propName, oldValue, newValue, null, true, out _));
+            Assert.True(TestMergeBaseItemData<Audio>(propName, Array.Empty<string>(), newValue, null, false, out _));
+
+            Assert.True(TestMergeBaseItemData<Audio>(propName, oldValue, Array.Empty<string>(), null, true, out _));
+        }
+
+        private static TheoryData<string, object, object> MergeBaseItemData_SimpleField_ReplacesAppropriately_TestData()
+            => new()
+            {
+                { "IndexNumber", 1, 2 },
+                { "ParentIndexNumber", 1, 2 },
+                { "ProductionYear", 1, 2 },
+                { "CommunityRating", 1.0f, 2.0f },
+                { "CriticRating", 1.0f, 2.0f },
+                { "EndDate", DateTime.UnixEpoch, DateTime.Now },
+                { "PremiereDate", DateTime.UnixEpoch, DateTime.Now },
+                { "Video3DFormat", Video3DFormat.HalfSideBySide, Video3DFormat.FullSideBySide }
+            };
+
+        [Theory]
+        [MemberData(nameof(MergeBaseItemData_SimpleField_ReplacesAppropriately_TestData))]
+        public void MergeBaseItemData_SimpleField_ReplacesAppropriately(string propName, object oldValue, object newValue)
+        {
+            // Use type Movie to allow testing of Video3DFormat
+            Assert.False(TestMergeBaseItemData<Movie>(propName, oldValue, newValue, null, false, out _));
+
+            Assert.True(TestMergeBaseItemData<Movie>(propName, oldValue, newValue, null, true, out _));
+            Assert.True(TestMergeBaseItemData<Movie>(propName, null, newValue, null, false, out _));
+
+            Assert.True(TestMergeBaseItemData<Movie>(propName, oldValue, null, null, true, out _));
+        }
+
+        [Fact]
+        public void MergeBaseItemData_MergeTrailers_ReplacesAppropriately()
+        {
+            string propName = "RemoteTrailers";
+            var oldValue = new[]
+            {
+                new MediaUrl
+                {
+                    Name = "Name 1",
+                    Url = "URL 1"
+                }
+            };
+            var newValue = new[]
+            {
+                new MediaUrl
+                {
+                    Name = "Name 2",
+                    Url = "URL 2"
+                }
+            };
+
+            Assert.False(TestMergeBaseItemData<Movie>(propName, oldValue, newValue, null, false, out _));
+
+            Assert.True(TestMergeBaseItemData<Movie>(propName, oldValue, newValue, null, true, out _));
+            Assert.True(TestMergeBaseItemData<Movie>(propName, Array.Empty<MediaUrl>(), newValue, null, false, out _));
+
+            Assert.True(TestMergeBaseItemData<Movie>(propName, oldValue, Array.Empty<MediaUrl>(), null, true, out _));
+        }
+
+        [Fact]
+        public void MergeBaseItemData_ProviderIds_MergesAppropriately()
+        {
+            var propName = "ProviderIds";
+            var oldValue = new Dictionary<string, string>
+            {
+                { "provider 1", "id 1" }
+            };
+
+            // overwrite provider id
+            var overwriteNewValue = new Dictionary<string, string>
+            {
+                { "provider 1", "id 2" }
+            };
+            Assert.False(TestMergeBaseItemData<Movie>(propName, new Dictionary<string, string>(oldValue), overwriteNewValue, null, false, out _));
+            TestMergeBaseItemData<Movie>(propName, new Dictionary<string, string>(oldValue), overwriteNewValue, null, true, out var overwritten);
+            Assert.Equal(overwriteNewValue, overwritten);
+
+            // merge without overwriting
+            var mergeNewValue = new Dictionary<string, string>
+            {
+                { "provider 1", "id 2" },
+                { "provider 2", "id 3" }
+            };
+            TestMergeBaseItemData<Movie>(propName, new Dictionary<string, string>(oldValue), mergeNewValue, null, false, out var merged);
+            var actual = (Dictionary<string, string>)merged!;
+            Assert.Equal("id 1", actual["provider 1"]);
+            Assert.Equal("id 3", actual["provider 2"]);
+
+            // empty source results in no change
+            TestMergeBaseItemData<Movie>(propName, new Dictionary<string, string>(oldValue), new Dictionary<string, string>(), null, true, out var notOverwritten);
+            Assert.Equal(oldValue, notOverwritten);
+        }
+
+        [Fact]
+        public void MergeBaseItemData_MergePeople_MergesAppropriately()
+        {
+            // PersonInfo in list is changed by merge, create new for every call
+            List<PersonInfo> GetOldValue()
+                => new()
+                {
+                    new PersonInfo
+                    {
+                        Name = "Name 1",
+                        ProviderIds = new Dictionary<string, string>
+                        {
+                            { "Provider 1", "1234" }
+                        }
+                    }
+                };
+
+            object? result;
+            List<PersonInfo> actual;
+
+            // overwrite provider id
+            var overwriteNewValue = new List<PersonInfo>
+            {
+                new()
+                {
+                    Name = "Name 2"
+                }
+            };
+            Assert.False(TestMergeBaseItemDataPerson(GetOldValue(), overwriteNewValue, null, false, out result));
+            // People not already in target are not merged into it from source
+            actual = (List<PersonInfo>)result!;
+            Assert.Single(actual);
+            Assert.Equal("Name 1", actual[0].Name);
+
+            Assert.True(TestMergeBaseItemDataPerson(GetOldValue(), overwriteNewValue, null, true, out _));
+            Assert.True(TestMergeBaseItemDataPerson(new List<PersonInfo>(), overwriteNewValue, null, false, out _));
+            Assert.True(TestMergeBaseItemDataPerson(null, overwriteNewValue, null, false, out _));
+
+            Assert.False(TestMergeBaseItemDataPerson(GetOldValue(), overwriteNewValue, MetadataField.Cast, true, out _));
+
+            // providers merge but don't overwrite existing keys
+            var mergeNewValue = new List<PersonInfo>
+            {
+                new()
+                {
+                    Name = "Name 1",
+                    ProviderIds = new Dictionary<string, string>
+                    {
+                        { "Provider 1", "5678" },
+                        { "Provider 2", "5678" }
+                    }
+                }
+            };
+            TestMergeBaseItemDataPerson(GetOldValue(), mergeNewValue, null, false, out result);
+            actual = (List<PersonInfo>)result!;
+            Assert.Single(actual);
+            Assert.Equal("Name 1", actual[0].Name);
+            Assert.Equal(2, actual[0].ProviderIds.Count);
+            Assert.Equal("1234", actual[0].ProviderIds["Provider 1"]);
+            Assert.Equal("5678", actual[0].ProviderIds["Provider 2"]);
+
+            // picture adds if missing but won't overwrite (forcing overwrites entire list, not entries in merged PersonInfo)
+            var mergePicture1 = new List<PersonInfo>
+            {
+                new()
+                {
+                    Name = "Name 1",
+                    ImageUrl = "URL 1"
+                }
+            };
+            TestMergeBaseItemDataPerson(GetOldValue(), mergePicture1, null, false, out result);
+            actual = (List<PersonInfo>)result!;
+            Assert.Single(actual);
+            Assert.Equal("Name 1", actual[0].Name);
+            Assert.Equal("URL 1", actual[0].ImageUrl);
+            var mergePicture2 = new List<PersonInfo>
+            {
+                new()
+                {
+                    Name = "Name 1",
+                    ImageUrl = "URL 2"
+                }
+            };
+            TestMergeBaseItemDataPerson(mergePicture1, mergePicture2, null, false, out result);
+            actual = (List<PersonInfo>)result!;
+            Assert.Single(actual);
+            Assert.Equal("Name 1", actual[0].Name);
+            Assert.Equal("URL 1", actual[0].ImageUrl);
+
+            // empty source can be forced to overwrite a target with data
+            Assert.True(TestMergeBaseItemDataPerson(GetOldValue(), new List<PersonInfo>(), null, true, out _));
+        }
+
+        private static bool TestMergeBaseItemDataPerson(List<PersonInfo>? oldValue, List<PersonInfo>? newValue, MetadataField? lockField, bool replaceData, out object? actualValue)
+        {
+            var source = new MetadataResult<Movie>
+            {
+                Item = new Movie(),
+                People = newValue
+            };
+
+            var target = new MetadataResult<Movie>
+            {
+                Item = new Movie(),
+                People = oldValue
+            };
+
+            var lockedFields = lockField == null ? Array.Empty<MetadataField>() : new[] { (MetadataField)lockField };
+            ProviderUtils.MergeBaseItemData(source, target, lockedFields, replaceData, false);
+
+            actualValue = target.People;
+            return newValue?.Equals(actualValue) ?? actualValue == null;
+        }
+
+        /// <summary>
+        /// Makes a call to <see cref="ProviderUtils.MergeBaseItemData{T}"/> with the provided parameters and returns whether the target changed or not.
+        ///
+        /// Reflection is used to allow testing of all fields using the same logic, rather than relying on copy/pasting test code for each field.
+        /// </summary>
+        /// <param name="propName">The property to test.</param>
+        /// <param name="oldValue">The initial value in the target object.</param>
+        /// <param name="newValue">The initial value in the source object.</param>
+        /// <param name="lockField">The metadata field that locks this property if the field should be locked, or <c>null</c> to leave unlocked.</param>
+        /// <param name="replaceData">Passed through to <see cref="ProviderUtils.MergeBaseItemData{T}"/>.</param>
+        /// <param name="actualValue">The resulting value set to the target.</param>
+        /// <typeparam name="TItemType">The <see cref="BaseItem"/> type to test on.</typeparam>
+        /// <returns><c>true</c> if the property on the target updates to match the source value when<see cref="ProviderUtils.MergeBaseItemData{T}"/> is called.</returns>
+        private static bool TestMergeBaseItemData<TItemType>(string propName, object? oldValue, object? newValue, MetadataField? lockField, bool replaceData, out object? actualValue)
+            where TItemType : BaseItem, new()
+        {
+            var property = typeof(TItemType).GetProperty(propName)!;
+
+            var source = new MetadataResult<TItemType>
+            {
+                Item = new TItemType()
+            };
+            property.SetValue(source.Item, newValue);
+
+            var target = new MetadataResult<TItemType>
+            {
+                Item = new TItemType()
+            };
+            property.SetValue(target.Item, oldValue);
+
+            var lockedFields = lockField == null ? Array.Empty<MetadataField>() : new[] { (MetadataField)lockField };
+            ProviderUtils.MergeBaseItemData(source, target, lockedFields, replaceData, false);
+
+            actualValue = property.GetValue(target.Item);
+            return newValue?.Equals(actualValue) ?? actualValue == null;
+        }
+    }
+}