Upgrading to Lotus v2.0

Lotus v2.0 is not released yet. This guide grows while the 1.x line is current: each time a 1.x release deprecates something, the item is added here with the replacement. Every item compiles with a warning on 1.x and is removed in v2.0, so a host app or adapter can migrate one item at a time and reach v2.0 with nothing left to change.

The full list lives in the Deprecated sections of the CHANGELOG.

1. Lotus.Source.Adapters.Ecto.SQL.* moved to Lotus.SQL.*

The SQL helpers that any SQL engine needs sat under the Ecto adapter's namespace, although none of them depends on Ecto. They now live in the neutral Lotus.SQL namespace, next to Lotus.Query.Tokenizer, with the same functions:

The old modules delegate to the new ones and every function is marked @deprecated, so the compiler names the replacement at each call site.

Who is affected: a custom Lotus.Source.Adapters.Ecto.Dialect such as lotus_clickhouse, and any adapter that reuses the helpers directly. Host apps that go through Lotus.Source.Adapter callbacks (apply_filters/3, apply_sorts/3, validate_statement/3, validate_identifier/3, parse_qualified_name/2) are not affected.

-  alias Lotus.Source.Adapters.Ecto.SQL.FilterInjector
-  alias Lotus.Source.Adapters.Ecto.SQL.SortInjector
-  alias Lotus.Source.Adapters.Ecto.SQL.Transformer
+  alias Lotus.SQL.FilterInjector
+  alias Lotus.SQL.SortInjector
+  alias Lotus.SQL.Transformer

The delegates are removed in v2.0.

2. Lotus.Preflight.Relations no longer stores state in the process dictionary

Lotus.Preflight.Relations.put/1, get/0, take/0 and clear/0 are deprecated and removed in v2.0. They kept a preflight outcome in the process dictionary, which is invisible to supervision, leaks across queries in a reused process and cannot cross a Task boundary. Lotus.Runner carries the outcome as a value and has not touched the process dictionary since the outcome started travelling through the pipeline.

Who is affected: a host or middleware that stored an outcome itself and read it back later. Nothing in lotus_web does.

Where to get the outcome instead:

• In middleware, read the :relations key of the :before_execute or :after_query payload. Both carry the same value: a {schema, table} list, {:unrestricted, reason} or {:skipped, reason}.
• Anywhere else, call Lotus.Preflight.analyze/4 with the adapter and the statement and keep the result in your own state.

   def call(:before_execute, payload, _opts) do
-    relations = Lotus.Preflight.Relations.get()
+    relations = payload.relations
     gate(relations, payload)
   end

Lotus.Preflight.Relations.to_list/1 and the relation/0 and outcome/0 types stay.