fix: Support non-public PostgreSQL schemas in resource generator (#631)

- Add schema field to generated resources when table is in non-public schema
- Fix SQL queries to use schema-qualified table names for foreign keys and constraints
- Update index queries to respect actual schema instead of hardcoded 'public'
- Add test coverage for tables in custom schemas with foreign keys and indexes

* fix: guard against missing snapshot directories in migration generator

Fixes crash when generating migrations for resources in non-public schemas
where the snapshot directory doesn't exist yet.

* chore: run mix format

Author: elliotb

lib/migration_generator/migration_generator.ex

@@ -649,14 +649,19 @@ defmodule AshPostgres.MigrationGenerator do
       folder = get_snapshot_folder(snapshot, opts)
       snapshot_path = get_snapshot_path(snapshot, folder)
 
-      snapshot_path
-      |> File.ls!()
-      |> Enum.filter(&String.contains?(&1, "_dev.json"))
-      |> Enum.each(fn snapshot_name ->
+      # Guard against missing directories - can happen for new resources or when
+      # get_snapshot_path's fallback logic returns a non-existent path for
+      # resources in non-public schemas
+      if File.dir?(snapshot_path) do
         snapshot_path
-        |> Path.join(snapshot_name)
-        |> File.rm!()
-      end)
+        |> File.ls!()
+        |> Enum.filter(&String.contains?(&1, "_dev.json"))
+        |> Enum.each(fn snapshot_name ->
+          snapshot_path
+          |> Path.join(snapshot_name)
+          |> File.rm!()
+        end)
+      end
     end)
   end
 

lib/resource_generator/resource_generator.ex

@@ -115,6 +115,7 @@ if Code.ensure_loaded?(Igniter) do
         postgres do
           table #{inspect(table_spec.table_name)}
           repo #{inspect(table_spec.repo)}
+          #{schema_option(table_spec)}
           #{no_migrate_flag}
           #{references(table_spec, opts[:no_migrations])}
           #{custom_indexes(table_spec, opts[:no_migrations])}
@@ -144,6 +145,12 @@ if Code.ensure_loaded?(Igniter) do
       end)
     end
 
+    defp schema_option(%{schema: schema}) when schema != "public" do
+      "schema #{inspect(schema)}"
+    end
+
+    defp schema_option(_), do: ""
+
     defp default_actions(opts) do
       cond do
         opts[:default_actions] && opts[:public] ->

lib/resource_generator/spec.ex

@@ -122,7 +122,13 @@ defmodule AshPostgres.ResourceGenerator.Spec do
     result
   end
 
+  defp qualified_table_name(%{schema: schema, table_name: table_name}) do
+    "#{schema}.#{table_name}"
+  end
+
   defp add_foreign_keys(spec) do
+    qualified_table = qualified_table_name(spec)
+
     %Postgrex.Result{rows: fkey_rows} =
       spec.repo.query!(
         """
@@ -178,7 +184,7 @@ defmodule AshPostgres.ResourceGenerator.Spec do
                 constraints.update_rule,
                 constraints.delete_rule
         """,
-        [spec.table_name, spec.schema],
+        [qualified_table, spec.schema],
         log: false
       )
 
@@ -218,6 +224,8 @@ defmodule AshPostgres.ResourceGenerator.Spec do
   end
 
   defp add_check_constraints(spec) do
+    qualified_table = qualified_table_name(spec)
+
     %Postgrex.Result{rows: check_constraint_rows} =
       spec.repo.query!(
         """
@@ -230,7 +238,7 @@ defmodule AshPostgres.ResourceGenerator.Spec do
             contype = 'c'
             AND conrelid::regclass::text = $1
         """,
-        [spec.table_name],
+        [qualified_table],
         log: false
       )
 
@@ -278,7 +286,7 @@ defmodule AshPostgres.ResourceGenerator.Spec do
           LEFT JOIN
               pg_constraint c ON c.conindid = ix.indexrelid AND c.contype = 'p'
           JOIN
-              pg_indexes idx ON idx.indexname = i.relname AND idx.schemaname = 'public' -- Adjust schema name if necessary
+              pg_indexes idx ON idx.indexname = i.relname AND idx.schemaname = $2
           JOIN information_schema.tables ta
               ON ta.table_name = t.relname
           WHERE
@@ -312,7 +320,7 @@ defmodule AshPostgres.ResourceGenerator.Spec do
           LEFT JOIN
               pg_constraint c ON c.conindid = ix.indexrelid AND c.contype = 'p'
           JOIN
-              pg_indexes idx ON idx.indexname = i.relname AND idx.schemaname = 'public' -- Adjust schema name if necessary
+              pg_indexes idx ON idx.indexname = i.relname AND idx.schemaname = $2
           JOIN information_schema.tables ta
               ON ta.table_name = t.relname
           WHERE

test/resource_generator_test.exs

@@ -62,4 +62,134 @@ defmodule AshPostgres.ResourceGeenratorTests do
     end
     """)
   end
+
+  test "a resource is generated from a table in a non-public schema with foreign keys and indexes" do
+    AshPostgres.TestRepo.query!("CREATE SCHEMA IF NOT EXISTS inventory")
+
+    AshPostgres.TestRepo.query!("DROP TABLE IF EXISTS inventory.products CASCADE")
+    AshPostgres.TestRepo.query!("DROP TABLE IF EXISTS inventory.warehouses CASCADE")
+
+    AshPostgres.TestRepo.query!("""
+    CREATE TABLE inventory.warehouses (
+      id UUID DEFAULT uuid_generate_v4() PRIMARY KEY,
+      name VARCHAR(255) NOT NULL,
+      location VARCHAR(255)
+    )
+    """)
+
+    AshPostgres.TestRepo.query!("CREATE INDEX warehouses_name_idx ON inventory.warehouses(name)")
+
+    AshPostgres.TestRepo.query!("""
+    CREATE TABLE inventory.products (
+      id UUID DEFAULT uuid_generate_v4() PRIMARY KEY,
+      name VARCHAR(255) NOT NULL,
+      warehouse_id UUID REFERENCES inventory.warehouses(id) ON DELETE CASCADE,
+      quantity INTEGER
+    )
+    """)
+
+    AshPostgres.TestRepo.query!(
+      "CREATE INDEX products_warehouse_id_idx ON inventory.products(warehouse_id)"
+    )
+
+    test_project()
+    |> Igniter.compose_task("ash_postgres.gen.resources", [
+      "MyApp.Inventory",
+      "--tables",
+      "inventory.warehouses,inventory.products",
+      "--yes",
+      "--repo",
+      "AshPostgres.TestRepo"
+    ])
+    |> assert_creates("lib/my_app/inventory/warehouse.ex", """
+    defmodule MyApp.Inventory.Warehouse do
+      use Ash.Resource,
+        domain: MyApp.Inventory,
+        data_layer: AshPostgres.DataLayer
+
+      actions do
+        defaults([:read, :destroy, create: :*, update: :*])
+      end
+
+      postgres do
+        table("warehouses")
+        repo(AshPostgres.TestRepo)
+        schema("inventory")
+      end
+
+      attributes do
+        uuid_primary_key :id do
+          public?(true)
+        end
+
+        attribute :name, :string do
+          allow_nil?(false)
+          public?(true)
+        end
+
+        attribute :location, :string do
+          public?(true)
+        end
+      end
+
+      relationships do
+        has_many :products, MyApp.Inventory.Product do
+          public?(true)
+        end
+      end
+    end
+    """)
+    |> assert_creates("lib/my_app/inventory/product.ex", """
+    defmodule MyApp.Inventory.Product do
+      use Ash.Resource,
+        domain: MyApp.Inventory,
+        data_layer: AshPostgres.DataLayer
+
+      actions do
+        defaults([:read, :destroy, create: :*, update: :*])
+      end
+
+      postgres do
+        table("products")
+        repo(AshPostgres.TestRepo)
+        schema("inventory")
+
+        references do
+          reference :warehouse do
+            on_delete(:delete)
+          end
+        end
+      end
+
+      attributes do
+        uuid_primary_key :id do
+          public?(true)
+        end
+
+        uuid_primary_key :id do
+          public?(true)
+        end
+
+        attribute :name, :string do
+          public?(true)
+        end
+
+        attribute :name, :string do
+          allow_nil?(false)
+          public?(true)
+        end
+
+        attribute :quantity, :integer do
+          public?(true)
+        end
+      end
+
+      relationships do
+        belongs_to :warehouse, MyApp.Inventory.Warehouse do
+          public?(true)
+        end
+      end
+    end
+    """)
+  end
 end