public PostgreSqlDatabaseProvider(
string connectionString,
string dbNamePrefix,
string?templateDb,
bool enableLogging,
Func <TDbContext, Task>?seed,
Action <NpgsqlDbContextOptionsBuilder>?npgsqlOptions,
Action <DbContextOptionsBuilder <TDbContext> >?dbContextOptions)
{
this.connectionString = connectionString;
this.templateDb = templateDb;
this.seed = seed;
//The max identifier length of postgres is 63 chars. Minus the 22 we're using from the base64-guid the prefix must be max 41 chars.
if (dbNamePrefix.Length > 41)
{
throw new ArgumentException("The max. allowed length of the dbNamePrefix is 41 characters.");
}
dbName = dbNamePrefix + Convert.ToBase64String(Guid.NewGuid().ToByteArray()).TrimEnd('=');
var testDbConnectionString = PostgreSqlUtil.ReplaceDatabaseName(connectionString, dbName);
var builder = new DbContextOptionsBuilder <TDbContext>().UseNpgsql(testDbConnectionString, npgsqlOptions);
dbContextOptions?.Invoke(builder);
if (enableLogging)
{
builder.UseLoggerFactory(new LoggerFactory(new[] { new XUnitLoggerProvider() }));
}
builder.AddInterceptors(new CreateDatabaseInterceptor <TDbContext>(CreateDatabase));
options = builder.Options;
}
public void DropDatabase(TDbContext dbContext)
{
if (!dbCreated)
{
return;
}
dbCreated = false;
pgVersion ??= PostgreSqlUtil.GetServerVersion(connectionString);
PostgreSqlUtil.DropDb(connectionString, dbName, pgVersion);
}
public void CreateDatabase(TDbContext dbContext)
{
if (dbCreated)
{
return;
}
// Creating a DB from a template can cause an exception when done in parallel.
// The lock usually prevents this, however, we still encounter race conditions
// where we just have to retry.
// 55006: source database "test_template" is being accessed by other users
Policy.Handle <NpgsqlException>(e => e.SqlState == "55006")
.WaitAndRetry(30, _ => TimeSpan.FromMilliseconds(500))
.Execute(CreateDatabase);
void CreateDatabase()
{
if (dbCreated)
{
return;
}
PostgreSqlUtil.CreateDatabase(connectionString, dbName, templateDb);
dbCreated = true;
//if no template database was given, run the migrations
if (templateDb == null)
{
dbContext.Database.Migrate();
}
//For some weird reason any async access to the dbContext causes some kind of task deadlock. The cause for it is the AsyncTestSyncContext from XUnit.
//It causes .Wait() to lock indefinitely. It doesn't relate to the connection or the migrate above.
//Seems somehow connected to dbContext.SaveChangesAsync() when called in the seed. (at least in my tests).
//Running the seed with an extra Task.Run() around works...
Task.Run(() => seed?.Invoke(dbContext).Wait()).Wait();
}
}