feat: add create? and drop? callbacks to AshPostgres.Repo (#143)

Co-authored-by: Zach Daniel <zach@zachdaniel.dev>

lib/mix/tasks/ash_postgres.create.ex

@@ -34,7 +34,9 @@ defmodule Mix.Tasks.AshPostgres.Create do
   def run(args) do
     {opts, _} = OptionParser.parse!(args, strict: @switches, aliases: @aliases)
 
-    repos = AshPostgres.MixHelpers.repos!(opts, args)
+    repos =
+      AshPostgres.MixHelpers.repos!(opts, args)
+      |> Enum.filter(fn repo -> repo.create? end)
 
     repo_args =
       Enum.flat_map(repos, fn repo ->

lib/mix/tasks/ash_postgres.drop.ex

@@ -44,7 +44,9 @@ defmodule Mix.Tasks.AshPostgres.Drop do
     {opts, _} = OptionParser.parse!(args, strict: @switches, aliases: @aliases)
     opts = Keyword.merge(@default_opts, opts)
 
-    repos = AshPostgres.MixHelpers.repos!(opts, args)
+    repos =
+      AshPostgres.MixHelpers.repos!(opts, args)
+      |> Enum.filter(fn repo -> repo.drop? end)
 
     repo_args =
       Enum.flat_map(repos, fn repo ->

lib/repo.ex

@@ -71,6 +71,10 @@ defmodule AshPostgres.Repo do
 
   @doc "Allows overriding a given migration type for *all* fields, for example if you wanted to always use :timestamptz for :utc_datetime fields"
   @callback override_migration_type(atom) :: atom
+  @doc "Should the repo should be created by `mix ash_postgres.create`?"
+  @callback create?() :: boolean
+  @doc "Should the repo should be dropped by `mix ash_postgres.drop`?"
+  @callback drop?() :: boolean
 
   defmacro __using__(opts) do
     quote bind_quoted: [opts: opts] do
@@ -91,6 +95,9 @@ defmodule AshPostgres.Repo do
       def migrations_path, do: nil
       def default_prefix, do: "public"
       def override_migration_type(type), do: type
+      def create?, do: true
+      def drop?, do: true
+
 
       def transaction!(fun) do
         case fun.() do
@@ -226,7 +233,9 @@ defmodule AshPostgres.Repo do
                      all_tenants: 0,
                      tenant_migrations_path: 0,
                      default_prefix: 0,
-                     override_migration_type: 1
+                     override_migration_type: 1,
+                     create?: 0,
+                     drop?: 0
     end
   end
 end