Migration builder ordering jumbled

[anton-schieber]

v0.2.4 works fine, but after v0.2.5, if I regenerate the migration from scratch it fails:

Previous order

protected override void Up(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.EnsureSchema(
                name: "auth");

            migrationBuilder.AlterDatabase()
                .Annotation("Npgsql:PostgresExtension:timescaledb", ",,");

New order

        protected override void Up(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.EnsureSchema(
                name: "auth");

            migrationBuilder.CreateIndex(
                name: "ix_users_email",
                schema: "auth",
                table: "users",
                column: "email",
                unique: true);

Clearly the index cant be created before the table so it fails

[anton-schieber]

Im trying to reproduce it but having now luck so far

[sebastian-ederer]

Thanks for the find! I will start fixing issues on Monday again. I also want to gain higher test coverage, so less bugs are re-introduced. Please be patient. 🙏

[sebastian-ederer]

I think I've found the issue. In TimescaleMigrationsModelDiffer I've used Sort() to ensure the correct order of the operations:

allOperations.Sort((op1, op2) => GetOperationPriority(op1).CompareTo(GetOperationPriority(op2)));
return allOperations;

However, Sort() is not a stable sort operation when you've got elements with the same priorities in the list, because depending on certain thresholds, the method switches between sorting algorithms.

I am using OrderBy() instead, now. this should lead to a stable sorting behavior.

List<MigrationOperation> sortedOperations = [.. allOperations.OrderBy(GetOperationPriority)];
return sortedOperations;

I also included tests that confirm this. I will close this issue now. If the bug appears again, please let me know! 😄

[anton-schieber]

Very nice, ill give it a test