.NET 6 Coding Patterns + Unit Tests (#823)

* Refactored all files to have Interfaces within the same file. Started moving over to file-scoped namespaces.

* Refactored common methods for getting underlying file's cover, pages, and extracting into 1 interface.

* More refactoring around removing dependence on explicit filetype testing for getting information.

* Code is buildable, tests are broken. Huge refactor (not completed) which makes most of DirectoryService testable with a mock filesystem (and thus the services that utilize it).

* Finished porting DirectoryService to use mocked filesystem implementation.

* Added a null check

* Added a null check

* Finished all unit tests for DirectoryService.

* Some misc cleanup on the code

* Fixed up some bugs from refactoring scan loop.

* Implemented CleanupService testing and refactored more of DirectoryService to be non-static.

Fixed a bug where cover file cleanup wasn't properly finding files due to a regex bug.

* Fixed an issue in CleanupBackup() where we weren't properly selecting database files older than 30 days. Finished CleanupService Tests.

* Refactored Flatten and RemoveNonImages to directory service to allow CacheService to be testable.

* Finally have CacheService tested. Rewrote GetCachedPagePath() to be much more straightforward & performant.

* Updated DefaultParserTests.cs to contain all existing tests and follow new test layout format.

* All tests fixed up

API/Data/Repositories/PersonRepository.cs

@@ -2,59 +2,65 @@
 using System.Linq;
 using System.Threading.Tasks;
 using API.Entities;
-using API.Interfaces.Repositories;
 using AutoMapper;
 using Microsoft.EntityFrameworkCore;
 
-namespace API.Data.Repositories
+namespace API.Data.Repositories;
+
+public interface IPersonRepository
 {
-    public class PersonRepository : IPersonRepository
+    void Attach(Person person);
+    void Remove(Person person);
+    Task<IList<Person>> GetAllPeople();
+    Task RemoveAllPeopleNoLongerAssociated(bool removeExternal = false);
+}
+
+public class PersonRepository : IPersonRepository
+{
+    private readonly DataContext _context;
+    private readonly IMapper _mapper;
+
+    public PersonRepository(DataContext context, IMapper mapper)
     {
-        private readonly DataContext _context;
-        private readonly IMapper _mapper;
+        _context = context;
+        _mapper = mapper;
+    }
 
-        public PersonRepository(DataContext context, IMapper mapper)
-        {
-            _context = context;
-            _mapper = mapper;
-        }
+    public void Attach(Person person)
+    {
+        _context.Person.Attach(person);
+    }
 
-        public void Attach(Person person)
-        {
-            _context.Person.Attach(person);
-        }
+    public void Remove(Person person)
+    {
+        _context.Person.Remove(person);
+    }
 
-        public void Remove(Person person)
-        {
-            _context.Person.Remove(person);
-        }
+    public async Task<Person> FindByNameAsync(string name)
+    {
+        var normalizedName = Parser.Parser.Normalize(name);
+        return await _context.Person
+            .Where(p => normalizedName.Equals(p.NormalizedName))
+            .SingleOrDefaultAsync();
+    }
 
-        public async Task<Person> FindByNameAsync(string name)
-        {
-            var normalizedName = Parser.Parser.Normalize(name);
-            return await _context.Person
-                .Where(p => normalizedName.Equals(p.NormalizedName))
-                .SingleOrDefaultAsync();
-        }
+    public async Task RemoveAllPeopleNoLongerAssociated(bool removeExternal = false)
+    {
+        var peopleWithNoConnections = await _context.Person
+            .Include(p => p.SeriesMetadatas)
+            .Include(p => p.ChapterMetadatas)
+            .Where(p => p.SeriesMetadatas.Count == 0 && p.ChapterMetadatas.Count == 0)
+            .ToListAsync();
 
-        public async Task RemoveAllPeopleNoLongerAssociated(bool removeExternal = false)
-        {
-            var peopleWithNoConnections = await _context.Person
-                .Include(p => p.SeriesMetadatas)
-                .Include(p => p.ChapterMetadatas)
-                .Where(p => p.SeriesMetadatas.Count == 0 && p.ChapterMetadatas.Count == 0)
-                .ToListAsync();
+        _context.Person.RemoveRange(peopleWithNoConnections);
 
-            _context.Person.RemoveRange(peopleWithNoConnections);
-
-            await _context.SaveChangesAsync();
-        }
+        await _context.SaveChangesAsync();
+    }
 
 
-        public async Task<IList<Person>> GetAllPeople()
-        {
-            return await _context.Person
-                .ToListAsync();
-        }
+    public async Task<IList<Person>> GetAllPeople()
+    {
+        return await _context.Person
+            .ToListAsync();
     }
 }