Add execute_file/1 and /2 (#470)

Author: greg-rychlewski

lib/ecto/migration.ex

@@ -929,6 +929,31 @@ defmodule Ecto.Migration do
     Runner.execute %Command{up: up, down: down}
   end
 
+  @doc """
+  Executes a SQL command from a file.
+
+  The argument must be a path to a file containing a SQL command.
+
+  Reversible commands can be defined by calling `execute_file/2`.
+  """
+  def execute_file(path) when is_binary(path) do
+    command = File.read!(path)
+    Runner.execute command
+  end
+
+  @doc """
+  Executes reversible SQL commands from files.
+
+  Each argument must be a path to a file containing a SQL command.
+
+  See `execute/2` for more information on executing SQL commands.
+  """
+  def execute_file(up_path, down_path) when is_binary(up_path) and is_binary(down_path) do
+    up = File.read!(up_path)
+    down = File.read!(down_path)
+    Runner.execute %Command{up: up, down: down}
+  end
+
   @doc """
   Gets the migrator direction.
   """

test/ecto/migration_test.exs

@@ -3,9 +3,10 @@ defmodule Ecto.MigrationTest do
   # is global state, we can run it async as long as this is
   # the only test case that uses the Runner in async mode.
   use ExUnit.Case, async: true
-
   use Ecto.Migration
 
+  import Support.FileHelpers
+
   alias EctoSQL.TestRepo
   alias Ecto.Migration.{Table, Index, Reference, Constraint}
   alias Ecto.Migration.Runner
@@ -694,6 +695,16 @@ defmodule Ecto.MigrationTest do
     assert "SELECT 1" = last_command()
   end
 
+  test "forward: executes a command from a file" do
+    in_tmp fn _path ->
+      up_sql = ~s(CREATE TABLE IF NOT EXISTS "execute_file_table" \(i integer\))
+      File.write!("up.sql", up_sql)
+      execute_file "up.sql"
+      flush()
+      assert up_sql == last_command()
+    end
+  end
+
   test "fails gracefully with nested create" do
     assert_raise Ecto.MigrationError, "cannot execute nested commands", fn ->
       create table(:posts) do
@@ -857,5 +868,19 @@ defmodule Ecto.MigrationTest do
     assert "SELECT 2" = last_command()
   end
 
+  test "backward: reverses a command from a file" do
+    in_tmp fn _path ->
+      up_sql = ~s(CREATE TABLE IF NOT EXISTS "execute_file_table" \(i integer\))
+      File.write!("up.sql", up_sql)
+
+      down_sql = ~s(DROP TABLE IF EXISTS "execute_file_table")
+      File.write!("down.sql", down_sql)
+
+      execute_file "up.sql", "down.sql"
+      flush()
+      assert down_sql == last_command()
+    end
+  end
+
   defp last_command(), do: Process.get(:last_command)
 end