Good library.

I’ve read the code and found a couple of fairly obvious bugs (like non-escaped strings in generated CSV) and limitations (like reading everything in memory), so I made a PR with fixes.

I am also providing fairly cheap consultancy services if you want to have this kind of review and contribution in your private projects.

v0.5.0 Released

Version 0.5.0 is now available. This release marks a big step toward 1.0.0 — it covers all the major changes I had planned. Now the focus shifts to gathering feedback, fixing bugs, and addressing any remaining breaking changes before 1.0.0 (though I don’t have any in mind).

The headline feature is stream support, which enables memory-efficient seeding of large datasets.

Both table/2 clauses return streams in the example below, but returning lists still works as before.

defmodule Blog.Seeder do
  use Blink

  def call do
    new()
    |> with_table("users")
    |> with_table("posts")
    |> run(Blog.Repo, timeout: :infinity)
  end

  def table(_seeder, "users") do
    Stream.map(1..200_000, fn i ->
      %{
        id: i,
        name: "User #{i}",
        email: "user#{i}@example.com",
        ...
        inserted_at: ~U[2024-01-01 00:00:00Z],
        updated_at: ~U[2024-01-01 00:00:00Z]
      }
    end)
  end
  
  def table(seeder, "posts") do
    users_stream = seeder.tables["users"]

    Stream.flat_map(users_stream, fn user ->
      for i <- 1..20 do
        %{
          id: (user.id - 1) * 20 + i,
          title: "Post #{i} by #{user.name}",
          body: "This is the content of post #{i}",
          user_id: user.id,
          ...
          inserted_at: ~U[2024-01-01 00:00:00Z],
          updated_at: ~U[2024-01-01 00:00:00Z]
        }
      end
    end)
  end
end

Other highlights

• JSONB support — nested maps are automatically JSON-encoded during insertion
• Configurable timeout — :timeout option for long-running transactions
• Configurable batch size — :batch_size option controls stream chunking (default: 10,000 rows)
• Performance improvement — CSV encoding executes significantly faster
• Bug fix — CSV escaping now correctly handles pipes, quotes, newlines, and backslashes

Breaking changes

• Blink.Store → Blink.Seeder
• insert/3 → run/3
• add_table/2 → with_table/2
• add_context/2 → with_context/2
• Return values simplified to :ok (raises on failure)
• Adapter call/4 callback now receives table_name as a string

Full changelog: v0.5.0 release

You missed a couple of other important things from my PR:

1. Doing

   try do
     adapter.call(...)
   rescue
     UndefinedFunctionError ->
       raise "Module #{inspect adapter} must implement call/4"
   end
   

   is a strange approach. Removing the try completely would result in the more readable and meaningful exception.

   Plus, it is a buggy approach. Take for example a situation then the call function itself calls an undefined function. This try clause would hide this error, making debugging a nightmare

2. You new approach opens and parses a CSV file twice in stream mode. First one to get the headers and second one to stream the data. This is not an issue when there is a one huge file, but it is an issue when there are a lot of small files. Opening a file is an operation which is more expensive than reading from a file