improvement: add custom migration types, and repo level override

.formatter.exs

@@ -14,6 +14,7 @@ locals_without_parens = [
   index: 2,
   message: 1,
   migrate?: 1,
+  migration_types: 1,
   name: 1,
   on_delete: 1,
   on_update: 1,

lib/ash_postgres.ex

@@ -24,6 +24,11 @@ defmodule AshPostgres do
     Extension.get_entities(resource, [:postgres, :references])
   end
 
+  @doc "A keyword list of customized migration types"
+  def migration_types(resource) do
+    Extension.get_opt(resource, [:postgres], :migration_types, nil, true)
+  end
+
   @doc "The configured check_constraints for a resource"
   def check_constraints(resource) do
     Extension.get_entities(resource, [:postgres, :check_constraints])

lib/data_layer.ex

@@ -237,6 +237,12 @@ defmodule AshPostgres.DataLayer do
         doc:
           "Whether or not to include this resource in the generated migrations with `mix ash.generate_migrations`"
       ],
+      migration_types: [
+        type: :keyword_list,
+        default: [],
+        doc:
+          "A keyword list of attribute names to the ecto migration type that should be used for that attribute. Only necessary if you need to override the defaults."
+      ],
       base_filter_sql: [
         type: :string,
         doc:

lib/migration_generator/migration_generator.ex

@@ -344,9 +344,22 @@ defmodule AshPostgres.MigrationGenerator do
     |> Enum.map(fn {attr, i} -> Map.put(attr, :order, i) end)
     |> Enum.group_by(& &1.name)
     |> Enum.map(fn {name, attributes} ->
+      size =
+        attributes
+        |> Enum.map(& &1.size)
+        |> Enum.filter(& &1)
+        |> case do
+          [] ->
+            nil
+
+          sizes ->
+            Enum.max(sizes)
+        end
+
       %{
         name: name,
         type: merge_types(Enum.map(attributes, & &1.type), name, table),
+        size: size,
         default: merge_defaults(Enum.map(attributes, & &1.default)),
         allow_nil?: Enum.any?(attributes, & &1.allow_nil?) || Enum.count(attributes) < count,
         generated?: Enum.any?(attributes, & &1.generated?),
@@ -1643,11 +1656,32 @@ defmodule AshPostgres.MigrationGenerator do
     |> Enum.map(fn attribute ->
       default = default(attribute, repo)
 
+      type =
+        AshPostgres.migration_types(resource)[attribute.name] || migration_type(attribute.type)
+
+      type =
+        if :erlang.function_exported(repo, :override_migration_type, 1) do
+          repo.override_migration_type(type)
+        else
+          type
+        end
+
+      {type, size} =
+        case type do
+          {:varchar, size} ->
+            {:varchar, size}
+
+          {:binary, size} ->
+            {:binary, size}
+
+          other ->
+            {other, nil}
+        end
+
       attribute
       |> Map.put(:default, default)
-      |> Map.update!(:type, fn type ->
-        migration_type(type)
-      end)
+      |> Map.put(:size, size)
+      |> Map.put(:type, type)
     end)
     |> Enum.map(fn attribute ->
       references = find_reference(resource, table, attribute)
@@ -1788,17 +1822,25 @@ defmodule AshPostgres.MigrationGenerator do
     snapshot
     |> Map.update!(:attributes, fn attributes ->
       Enum.map(attributes, fn attribute ->
-        %{attribute | type: sanitize_type(attribute.type)}
+        %{attribute | type: sanitize_type(attribute.type, attribute[:size])}
       end)
     end)
     |> Jason.encode!(pretty: true)
   end
 
-  defp sanitize_type({:array, type}) do
-    ["array", sanitize_type(type)]
+  defp sanitize_type({:array, type}, size) do
+    ["array", sanitize_type(type, size)]
   end
 
-  defp sanitize_type(type) do
+  defp sanitize_type(:varchar, size) when not is_nil(size) do
+    ["varchar", size]
+  end
+
+  defp sanitize_type(:binary, size) when not is_nil(size) do
+    ["binary", size]
+  end
+
+  defp sanitize_type(type, _) do
     type
   end
 
@@ -1856,9 +1898,24 @@ defmodule AshPostgres.MigrationGenerator do
   end
 
   defp load_attribute(attribute, table) do
+    type = load_type(attribute.type)
+
+    {type, size} =
+      case type do
+        {:varchar, size} ->
+          {:varchar, size}
+
+        {:binary, size} ->
+          {:binary, size}
+
+        other ->
+          {other, nil}
+      end
+
     attribute
-    |> Map.update!(:type, &load_type/1)
     |> Map.update!(:name, &String.to_atom/1)
+    |> Map.put(:type, type)
+    |> Map.put(:size, size)
     |> Map.put_new(:default, "nil")
     |> Map.update!(:default, &(&1 || "nil"))
     |> Map.update!(:references, fn
@@ -1897,6 +1954,14 @@ defmodule AshPostgres.MigrationGenerator do
     {:array, load_type(type)}
   end
 
+  defp load_type(["varchar", size]) do
+    {:varchar, size}
+  end
+
+  defp load_type(["binary", size]) do
+    {:binary, size}
+  end
+
   defp load_type(type) do
     String.to_atom(type)
   end

lib/migration_generator/operation.ex

@@ -86,6 +86,11 @@ defmodule AshPostgres.MigrationGenerator.Operation do
           "with: [#{source_attribute}: :#{destination_attribute}], match: :full"
         end
 
+      size =
+        if attribute[:size] do
+          "size: #{attribute[:size]}"
+        end
+
       [
         "add #{inspect(attribute.name)}",
         "references(:#{table}",
@@ -95,7 +100,8 @@ defmodule AshPostgres.MigrationGenerator.Operation do
           "name: #{inspect(reference.name)}",
           "type: #{inspect(reference_type(attribute, reference))}",
           on_delete(reference),
-          on_update(reference)
+          on_update(reference),
+          size
         ],
         ")",
         maybe_add_default(attribute.default),
@@ -117,6 +123,11 @@ defmodule AshPostgres.MigrationGenerator.Operation do
                 } = reference
             } = attribute
         }) do
+      size =
+        if attribute[:size] do
+          "size: #{attribute[:size]}"
+        end
+
       [
         "add #{inspect(attribute.name)}",
         "references(:#{table}",
@@ -125,6 +136,7 @@ defmodule AshPostgres.MigrationGenerator.Operation do
           "prefix: \"public\"",
           "name: #{inspect(reference.name)}",
           "type: #{inspect(reference_type(attribute, reference))}",
+          size,
           on_delete(reference),
           on_update(reference)
         ],
@@ -145,11 +157,17 @@ defmodule AshPostgres.MigrationGenerator.Operation do
               }
             } = attribute
         }) do
+      size =
+        if attribute.size do
+          "size: #{attribute.size}"
+        end
+
       [
         "add #{inspect(attribute.name)}",
         inspect(attribute.type),
         maybe_add_default(attribute.default),
         maybe_add_primary_key(attribute.primary_key?),
+        size,
         maybe_add_null(attribute.allow_nil?)
       ]
       |> join()
@@ -167,6 +185,11 @@ defmodule AshPostgres.MigrationGenerator.Operation do
                 } = reference
             } = attribute
         }) do
+      size =
+        if attribute[:size] do
+          "size: #{attribute[:size]}"
+        end
+
       [
         "add #{inspect(attribute.name)}",
         "references(:#{table}",
@@ -175,6 +198,7 @@ defmodule AshPostgres.MigrationGenerator.Operation do
           "name: #{inspect(reference.name)}",
           "type: #{inspect(reference_type(attribute, reference))}",
           "prefix: prefix()",
+          size,
           on_delete(reference),
           on_update(reference)
         ],
@@ -197,6 +221,11 @@ defmodule AshPostgres.MigrationGenerator.Operation do
                 } = reference
             } = attribute
         }) do
+      size =
+        if attribute[:size] do
+          "size: #{attribute[:size]}"
+        end
+
       [
         "add #{inspect(attribute.name)}",
         "references(:#{table}",
@@ -205,6 +234,7 @@ defmodule AshPostgres.MigrationGenerator.Operation do
           "name: #{inspect(reference.name)}",
           "type: #{inspect(reference_type(attribute, reference))}",
           "prefix: \"public\"",
+          size,
           on_delete(reference),
           on_update(reference)
         ],
@@ -221,6 +251,11 @@ defmodule AshPostgres.MigrationGenerator.Operation do
             %{references: %{table: table, destination_field: destination_field} = reference} =
               attribute
         }) do
+      size =
+        if attribute[:size] do
+          "size: #{attribute[:size]}"
+        end
+
       [
         "add #{inspect(attribute.name)}",
         "references(:#{table}",
@@ -228,6 +263,7 @@ defmodule AshPostgres.MigrationGenerator.Operation do
           "column: #{inspect(destination_field)}",
           "name: #{inspect(reference.name)}",
           "type: #{inspect(reference_type(attribute, reference))}",
+          size,
           on_delete(reference),
           on_update(reference)
         ],
@@ -260,11 +296,17 @@ defmodule AshPostgres.MigrationGenerator.Operation do
     end
 
     def up(%{attribute: attribute}) do
+      size =
+        if attribute[:size] do
+          "size: #{attribute[:size]}"
+        end
+
       [
         "add #{inspect(attribute.name)}",
         "#{inspect(attribute.type)}",
         maybe_add_null(attribute.allow_nil?),
         maybe_add_default(attribute.default),
+        size,
         maybe_add_primary_key(attribute.primary_key?)
       ]
       |> join()
@@ -342,10 +384,16 @@ defmodule AshPostgres.MigrationGenerator.Operation do
                } = reference
            } = attribute
          ) do
+      size =
+        if attribute[:size] do
+          "size: #{attribute[:size]}"
+        end
+
       join([
         "references(:#{table}, column: #{inspect(destination_field)}",
         "name: #{inspect(reference.name)}",
         "type: #{inspect(reference_type(attribute, reference))}",
+        size,
         "prefix: prefix()",
         on_delete(reference),
         on_update(reference),
@@ -369,11 +417,17 @@ defmodule AshPostgres.MigrationGenerator.Operation do
           "with: [#{source_attribute}: :#{destination_attribute}], match: :full"
         end
 
+      size =
+        if attribute[:size] do
+          "size: #{attribute[:size]}"
+        end
+
       join([
         "references(:#{table}, column: #{inspect(destination_field)}",
         with_match,
         "name: #{inspect(reference.name)}",
         "type: #{inspect(reference_type(attribute, reference))}",
+        size,
         on_delete(reference),
         on_update(reference),
         ")"
@@ -390,10 +444,16 @@ defmodule AshPostgres.MigrationGenerator.Operation do
                } = reference
            } = attribute
          ) do
+      size =
+        if attribute[:size] do
+          "size: #{attribute[:size]}"
+        end
+
       join([
         "references(:#{table}, column: #{inspect(destination_field)}, prefix: \"public\"",
         "name: #{inspect(reference.name)}",
         "type: #{inspect(reference_type(attribute, reference))}",
+        size,
         on_delete(reference),
         on_update(reference),
         ")"
@@ -410,10 +470,16 @@ defmodule AshPostgres.MigrationGenerator.Operation do
                } = reference
            } = attribute
          ) do
+      size =
+        if attribute[:size] do
+          "size: #{attribute[:size]}"
+        end
+
       join([
         "references(:#{table}, column: #{inspect(destination_field)}",
         "name: #{inspect(reference.name)}",
         "type: #{inspect(reference_type(attribute, reference))}",
+        size,
         on_delete(reference),
         on_update(reference),
         ")"

lib/repo.ex

@@ -35,6 +35,8 @@ defmodule AshPostgres.Repo do
   @callback migrations_path() :: String.t()
   @doc "The default prefix(postgres schema) to use when building queries"
   @callback default_prefix() :: String.t()
+  @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
 
   defmacro __using__(opts) do
     quote bind_quoted: [opts: opts] do
@@ -48,6 +50,7 @@ defmodule AshPostgres.Repo do
       def tenant_migrations_path, do: nil
       def migrations_path, do: nil
       def default_prefix, do: "public"
+      def override_migration_type(type), do: type
 
       def all_tenants do
         raise """
@@ -77,7 +80,8 @@ defmodule AshPostgres.Repo do
                      installed_extensions: 0,
                      all_tenants: 0,
                      tenant_migrations_path: 0,
-                     default_prefix: 0
+                     default_prefix: 0,
+                     override_migration_type: 1
     end
   end
 end

test/migration_generator_test.exs

@@ -67,6 +67,10 @@ defmodule AshPostgres.MigrationGeneratorTest do
       end)
 
       defposts do
+        postgres do
+          migration_types second_title: {:varchar, 16}
+        end
+
         identities do
           identity(:title, [:title])
         end
@@ -74,6 +78,7 @@ defmodule AshPostgres.MigrationGeneratorTest do
         attributes do
           uuid_primary_key(:id)
           attribute(:title, :string)
+          attribute(:second_title, :string)
         end
       end
 
@@ -116,6 +121,9 @@ defmodule AshPostgres.MigrationGeneratorTest do
       # the migration adds other attributes
       assert file_contents =~ ~S[add :title, :text]
 
+      # the migration adds custom attributes
+      assert file_contents =~ ~S[add :second_title, :varchar, size: 16]
+
       # the migration creates unique_indexes based on the identities of the resource
       assert file_contents =~ ~S{create unique_index(:posts, [:title], name: "posts_title_index")}
     end