/// <summary>
/// Applies the provided migrations to the target system. The engine does not check
/// if the specified migrations were already applied.
/// PLEASE NOTE: this method will not throw. You must check the resulting summary for errors that might have occurred.
/// </summary>
/// <param name="pendingMigrations">The list of migrations that should be applied.</param>
/// <param name="now">
/// The current time when the migration engine starts to execute (optional). Please use a UTC time stamp if possible. If
/// you do not provide a value, <see cref="DateTime.UtcNow" /> will be used.
/// </param>
/// <param name="cancellationToken">The token to cancel this asynchronous operation (optional).</param>
/// <returns>A summary of all migrations that have been applied in this run.</returns>
public virtual async Task <MigrationSummary <TMigrationInfo> > ApplyMigrationsAsync(List <PendingMigration <TMigrationVersion> >?pendingMigrations,
DateTime?now = null,
CancellationToken cancellationToken = default)
{
if (pendingMigrations.IsNullOrEmpty())
{
return(MigrationSummary <TMigrationInfo> .Empty);
}
var timeStamp = now ?? DateTime.UtcNow;
var appliedMigrations = new List <TMigrationInfo>(pendingMigrations.Count);
for (var i = 0; i < pendingMigrations.Count; i++)
{
var pendingMigration = pendingMigrations[i];
IMigrationSession <TMigrationContext, TMigrationInfo>?session = null;
TMigration?migration = default;
try
{
migration = MigrationFactory.CreateMigration(pendingMigration.MigrationType);
session = await SessionFactory.CreateSessionForMigrationAsync(migration, cancellationToken);
await migration.ApplyAsync(session.Context, cancellationToken);
var migrationInfo = CreateMigrationInfo(migration, timeStamp);
await session.StoreMigrationInfoAsync(migrationInfo, cancellationToken);
await session.SaveChangesAsync(cancellationToken);
appliedMigrations.Add(migrationInfo);
}
catch (Exception exception)
{
var error = new MigrationError <TMigrationVersion>(pendingMigration.MigrationVersion, exception);
return(new MigrationSummary <TMigrationInfo>(error, appliedMigrations));
}
finally
{
// ReSharper disable SuspiciousTypeConversion.Global -- clients of the library should be allowed to write disposable migrations
if (migration is IAsyncDisposable asyncDisposableMigration)
{
await asyncDisposableMigration.DisposeAsync();
}
else if (migration is IDisposable disposableMigration)
{
disposableMigration.Dispose();
}
// ReSharper restore SuspiciousTypeConversion.Global
if (session != null)
{
await session.DisposeAsync();
}
}
}
return(new MigrationSummary <TMigrationInfo>(appliedMigrations));
}