fix(core): return error when fn already exists (#168)

Author: giusdp

Makefile

@@ -12,6 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+export SHELL:=/bin/bash
+export SHELLOPTS:=$(if $(SHELLOPTS),$(SHELLOPTS):)pipefail:errexit
+
+.ONESHELL:
+
 .PHONY: build-core-image build-worker-image credo dial test
 
 SECRET_KEY_BASE ?= $(shell mix phx.gen.secret)
@@ -38,9 +43,12 @@ dial:
 
  ## Run test suite, launch Postgres with docker-compose
 test: 
+	function tearDown {
+		docker compose -f docker-compose.yml down
+	}
+	trap tearDown EXIT
 	mix deps.get
 	docker compose -f docker-compose.yml up --detach
 	mix core.utest
 	mix worker.utest
 	mix core.itest
-	docker compose -f docker-compose.yml down

apps/core/lib/core_web/controllers/fallback_controller.ex

@@ -42,6 +42,13 @@ defmodule CoreWeb.FallbackController do
     |> render(:"400")
   end
 
+  def call(conn, {:error, :conflict}) do
+    conn
+    |> put_status(:conflict)
+    |> put_view(CoreWeb.ErrorView)
+    |> render(:"409")
+  end
+
   def call(conn, {:error, :no_workers}) do
     res = %{errors: %{detail: "No worker available"}}
 

apps/core/lib/core_web/controllers/function_controller.ex

@@ -58,20 +58,36 @@ defmodule CoreWeb.FunctionController do
       {:error, :bad_params}
     else
       with {:ok, code} <- File.read(tmp_path),
-           {:ok, module} <- Modules.get_module_by_name(module_name),
-           {:ok, %Function{} = function} <-
-             %{"name" => fn_name, "code" => code}
+           {:ok, module} <- Modules.get_module_by_name(module_name) do
+        case %{"name" => fn_name, "code" => code}
              |> Map.put_new("module_id", module.id)
              |> Functions.create_function() do
-        event_results = Events.connect_events(fn_name, module_name, events_req)
-        sinks_results = DataSink.plug_data_sinks(fn_name, module_name, sinks_req)
+          {:ok, %Function{} = function} ->
+            Logger.info(
+              "Function Controller: function #{module_name}/#{fn_name} created successfully."
+            )
 
-        {status, render_params} =
-          build_render_params(%{function: function}, event_results, sinks_results, :created)
+            event_results = Events.connect_events(fn_name, module_name, events_req)
+            sinks_results = DataSink.plug_data_sinks(fn_name, module_name, sinks_req)
 
-        conn
-        |> put_status(status)
-        |> render("show.json", render_params)
+            {status, render_params} =
+              build_render_params(%{function: function}, event_results, sinks_results, :created)
+
+            conn
+            |> put_status(status)
+            |> render("show.json", render_params)
+
+          {:error, %{errors: [function_module_index_constraint: {"has already been taken", _}]}} ->
+            Logger.error("Function Controller: #{module_name}/#{fn_name} already exists.")
+            {:error, :conflict}
+
+          e ->
+            Logger.error(
+              "Function Controller: error while creating #{module_name}/#{fn_name}: #{inspect(e)}."
+            )
+
+            e
+        end
       end
     end
   end

apps/core/test/core_web/integration/controllers/function_controller_test.exs

@@ -209,6 +209,20 @@ defmodule CoreWeb.FunctionControllerTest do
                "sinks_metadata" => %{"successful" => 1, "failed" => 1}
              } = json_response(conn, 207)["data"]
     end
+
+    test "error when module doesn't exist", %{conn: conn} do
+      conn = post(conn, Routes.function_path(conn, :create, "non_existing_module"), @create_attrs)
+      assert json_response(conn, 404)["errors"] == %{"detail" => "Not Found"}
+    end
+
+    test "error when creating already existing function", %{conn: conn} do
+      module = module_fixture()
+      conn = post(conn, Routes.function_path(conn, :create, module.name), @create_attrs)
+      assert json_response(conn, 201)["data"] == %{"name" => "some_name"}
+
+      conn = post(conn, Routes.function_path(conn, :create, module.name), @create_attrs)
+      assert json_response(conn, 409)["errors"] == %{"detail" => "Conflict"}
+    end
   end
 
   describe "update function" do