MigrationDiscovery

Discovers all classes implementing IMigration via reflection and returns them sorted by Id.

namespace Cosmigrator;

public static class MigrationDiscovery
{
    public static List<IMigration> DiscoverAll(params Assembly[] assemblies);
}

Methods

Method	Returns	Description
DiscoverAll(params Assembly[])	List<IMigration>	Scans assemblies for IMigration implementations, instantiates them, returns sorted by Id

DiscoverAll

var migrations = MigrationDiscovery.DiscoverAll(Assembly.GetExecutingAssembly());

Parameter	Type	Description
assemblies	params Assembly[]	Assemblies to scan. If empty, defaults to Assembly.GetEntryAssembly()

How it works

1. Selects target assemblies — provided assemblies, or the entry assembly if none specified
2. Scans all types using assembly.GetTypes()
3. Filters to types that:
   • Implement IMigration
   • Are not abstract
   • Are not interfaces
4. Instantiates each via Activator.CreateInstance
5. Sorts by IMigration.Id (lexicographic)
6. Returns as List<IMigration>

Requirements for discovered types

• Must have a parameterless constructor (since Activator.CreateInstance is used)
• Must be concrete (not abstract, not interface)
• Must implement IMigration

Example

Given these classes in an assembly:

public class _20250101_000001_AddAge : IMigration { ... }
public class _20250101_000002_RemoveName : IMigration { ... }
public abstract class BaseMigration : IMigration { ... }  // skipped

DiscoverAll returns:

1. _20250101_000001_AddAge (Id: "20250101_000001")
2. _20250101_000002_RemoveName (Id: "20250101_000002")

BaseMigration is excluded because it's abstract.