Make map encoding configurable

Author: a-nassim

lib/ecto/adapters/sqlite3.ex

@@ -51,6 +51,9 @@ defmodule Ecto.Adapters.SQLite3 do
     * `:uuid_type` - Defaults to `:string`. Determines the type of `:uuid` columns.
       Possible values and column types are the same as for
       [binary IDs](#module-binary-id-types).
+    * `:map_type` - Defaults to `:string`. Determines the type of `:map` columns.
+      Set to `:binary` to use the [JSONB](https://sqlite.org/draft/jsonb.html)
+      storage format.
     * `:datetime_type` - Defaults to `:iso8601`. Determines how datetime fields are
       stored in the database. The allowed values are `:iso8601` and `:text_datetime`.
       `:iso8601` corresponds to a string of the form `YYYY-MM-DDThh:mm:ss` and

lib/ecto/adapters/sqlite3/data_type.ex

@@ -17,9 +17,7 @@ defmodule Ecto.Adapters.SQLite3.DataType do
   def column_type(:string, _opts), do: "TEXT"
   def column_type(:float, _opts), do: "NUMERIC"
   def column_type(:binary, _opts), do: "BLOB"
-  def column_type(:map, _opts), do: "TEXT"
   def column_type(:array, _opts), do: "TEXT"
-  def column_type({:map, _}, _opts), do: "TEXT"
   def column_type({:array, _}, _opts), do: "TEXT"
   def column_type(:date, _opts), do: "TEXT"
   def column_type(:utc_datetime, _opts), do: "TEXT"
@@ -50,6 +48,20 @@ defmodule Ecto.Adapters.SQLite3.DataType do
     end
   end
 
+  def column_type(:map, _opts) do
+    case Application.get_env(:ecto_sqlite3, :map_type, :string) do
+      :string -> "TEXT"
+      :binary -> "BLOB"
+    end
+  end
+
+  def column_type({:map, _}, _opts) do
+    case Application.get_env(:ecto_sqlite3, :map_type, :string) do
+      :string -> "TEXT"
+      :binary -> "BLOB"
+    end
+  end
+
   def column_type(:uuid, _opts) do
     case Application.get_env(:ecto_sqlite3, :uuid_type, :string) do
       :string -> "TEXT"

test/ecto/adapters/sqlite3/data_type_test.exs

@@ -5,10 +5,12 @@ defmodule Ecto.Adapters.SQLite3.DataTypeTest do
 
   setup do
     Application.put_env(:ecto_sqlite3, :binary_id_type, :string)
+    Application.put_env(:ecto_sqlite3, :map_type, :string)
     Application.put_env(:ecto_sqlite3, :uuid_type, :string)
 
     on_exit(fn ->
       Application.put_env(:ecto_sqlite3, :binary_id_type, :string)
+      Application.put_env(:ecto_sqlite3, :map_type, :string)
       Application.put_env(:ecto_sqlite3, :uuid_type, :string)
     end)
   end
@@ -46,12 +48,20 @@ defmodule Ecto.Adapters.SQLite3.DataTypeTest do
       assert DataType.column_type(:uuid, nil) == "BLOB"
     end
 
-    test ":map is TEXT" do
+    test ":map is TEXT or BLOB" do
       assert DataType.column_type(:map, nil) == "TEXT"
+
+      Application.put_env(:ecto_sqlite3, :map_type, :binary)
+
+      assert DataType.column_type(:map, nil) == "BLOB"
     end
 
-    test "{:map, _} is TEXT" do
+    test "{:map, _} is TEXT or BLOB" do
       assert DataType.column_type({:map, %{}}, nil) == "TEXT"
+
+      Application.put_env(:ecto_sqlite3, :map_type, :binary)
+
+      assert DataType.column_type({:map, %{}}, nil) == "BLOB"
     end
 
     test ":array is TEXT" do

test/ecto/integration/json_test.exs

@@ -1,13 +1,40 @@
 defmodule Ecto.Integration.JsonTest do
-  use Ecto.Integration.Case
+  use Ecto.Integration.Case, async: false
 
   alias Ecto.Adapters.SQL
   alias Ecto.Integration.TestRepo
   alias EctoSQLite3.Schemas.Setting
 
   @moduletag :integration
 
-  test "serializes json correctly" do
+  setup do
+    Application.put_env(:ecto_sqlite3, :map_type, :string)
+    on_exit(fn -> Application.put_env(:ecto_sqlite3, :map_type, :string) end)
+  end
+
+  test "serializes json correctly with string format" do
+    # Insert a record purposefully with atoms as the map key. We are going to
+    # verify later they were coerced into strings.
+    setting =
+      %Setting{}
+      |> Setting.changeset(%{properties: %{foo: "bar", qux: "baz"}})
+      |> TestRepo.insert!()
+
+    # Read the record back using ecto and confirm it
+    assert %Setting{properties: %{"foo" => "bar", "qux" => "baz"}} =
+             TestRepo.get(Setting, setting.id)
+
+    assert %{num_rows: 1, rows: [["bar"]]} =
+             SQL.query!(
+               TestRepo,
+               "select json_extract(properties, '$.foo') from settings where id = ?1",
+               [setting.id]
+             )
+  end
+
+  test "serializes json correctly with binary format" do
+    Application.put_env(:ecto_sqlite3, :map_type, :binary)
+
     # Insert a record purposefully with atoms as the map key. We are going to
     # verify later they were coerced into strings.
     setting =