Infrastructure Index (such as Unique Index on VersionInfo table) is not using IConventionSet

I have customized my FluentMigrator project using IConventionSet but it doesn’t seems to be considered when creating the infrastructure object (e.g. VersionInfo table’s indexes).

Example

I have the following class correctly configured in my project:

public class ProjectConstraintNameConvention : IConstraintConvention
{
    // Rest of code was omitted

    private static string GetConstraintName(ConstraintDefinition expression)
    {
        var sb = new StringBuilder();
        sb.Append("MYProject_");
        sb.Append(expression.IsPrimaryKeyConstraint ? "PK_" : "UC_");


        sb.Append(expression.TableName);
        foreach (var column in expression.Columns)
        {
            sb.Append('_').Append(column);
        }

        return sb.ToString();
    }
}

Running “Up” database, the following SQL is create:

CREATE UNIQUE INDEX UC_Version ON VersionInfo (Version ASC);

Instead of:

CREATE UNIQUE INDEX MYProject_UC_VersionInfo_Version ON VersionInfo (Version ASC);

I’m using version FluentMigrator/3.2.1

[tgharold]

Is this a .NET Core project where you are using AddFluentMigratorCore()?

If so, you need to register the IConventionSet after making the AddFluentMigratorCore() call in Startup.ConfigureServices(). See this sample for an example.

The reason for this (I think) is a line inside of AddFluentMigratorCore(). Because the IServicesCollection is LIFO (last in first out), if AddFluentMigratorCore() registers something to handle IConventionSet after you register it… the FM registration will trump your registration. The workaround is to register your IConventionSet after the FM registration.

Source:

https://github.com/fluentmigrator/fluentmigrator/blob/27eb0110ff14b4d32aed7d316ee5caf4dda20716/src/FluentMigrator.Runner/FluentMigratorServiceCollectionExtensions.cs#L101-L102

[tgharold]

Yes, I pulled TryAddScoped out of the MS documentation while doing some other work.

Generally, this method is used by library authors to avoid registering two copies of an instance in the container.