move some common logic into an extension method

Author: adelikat

TASVideos.Data/Entity/User.cs

@@ -221,4 +221,15 @@ public static IQueryable<User> ThatAreNotBanned(this IQueryable<User> query)
 		=> query.Where(u => !u.BannedUntil.HasValue || u.BannedUntil < DateTime.UtcNow);
 
 	public static bool IsBanned(this User user) => user.BannedUntil.HasValue && user.BannedUntil > DateTime.UtcNow;
+
+	public static IQueryable<SubmissionAuthor> ToSubmissionAuthors(this IQueryable<User> query, int submissionId, IList<string> authors)
+		=> query
+			.ForUsers(authors)
+			.Select(u => new SubmissionAuthor
+			{
+				SubmissionId = submissionId,
+				UserId = u.Id,
+				Author = u,
+				Ordinal = authors.IndexOf(u.UserName)
+			});
 }

TASVideos/Pages/Submissions/Edit.cshtml.cs

@@ -312,14 +312,7 @@ public async Task<IActionResult> OnPost()
 
 		submission.SubmissionAuthors.Clear();
 		submission.SubmissionAuthors.AddRange(await db.Users
-			.ForUsers(Submission.Authors)
-			.Select(u => new SubmissionAuthor
-			{
-				SubmissionId = submission.Id,
-				UserId = u.Id,
-				Author = u,
-				Ordinal = Submission.Authors.IndexOf(u.UserName)
-			})
+			.ToSubmissionAuthors(submission.Id, Submission.Authors)
 			.ToListAsync());
 
 		submission.GenerateTitle();

TASVideos/Pages/Submissions/Submit.cshtml.cs

@@ -152,14 +152,7 @@ await wikiPages.Add(new WikiCreateRequest
 		});
 
 		db.SubmissionAuthors.AddRange(await db.Users
-			.ForUsers(Authors)
-			.Select(u => new SubmissionAuthor
-			{
-				SubmissionId = submission.Id,
-				UserId = u.Id,
-				Author = u,
-				Ordinal = Authors.IndexOf(u.UserName)
-			})
+			.ToSubmissionAuthors(submission.Id, Authors)
 			.ToListAsync());
 
 		submission.GenerateTitle();