From 3faa246d02816ca4ef2b006da5895594104c8de6 Mon Sep 17 00:00:00 2001
From: Andrew Rosa <dev@andrewhr.io>
Date: Thu, 24 Mar 2022 14:48:59 -0300
Subject: [PATCH] Remove exporter race-condition on tests (#44)

Default exporter immediately attempts on start connect to
`:otel-collector` default port. As we don't have any collector running
on our test environment, this results in a few warnings. That's not an
issue in itself, as code immediately switches to another export, but
creates a lot of noise.

This patch moves the exporter setup to `config/test.exs`, essentially
removing the need to restart opentelemetry applicationn for each test
case. The only work setup blocks do is update the exporter's target pid.

The processor was changed to simple mode, available now, which also remove
another vector of (unlikely but theoretically possible) race-conditions.
---
 instrumentation/opentelemetry_ecto/config/test.exs    |  2 +-
 .../test/opentelemetry_ecto_test.exs                  | 11 +----------
 instrumentation/opentelemetry_phoenix/config/test.exs |  2 +-
 .../test/opentelemetry_phoenix_test.exs               | 10 +---------
 4 files changed, 4 insertions(+), 21 deletions(-)

diff --git a/instrumentation/opentelemetry_ecto/config/test.exs b/instrumentation/opentelemetry_ecto/config/test.exs
index 7a781d0..5087377 100644
--- a/instrumentation/opentelemetry_ecto/config/test.exs
+++ b/instrumentation/opentelemetry_ecto/config/test.exs
@@ -11,4 +11,4 @@ config :opentelemetry_ecto, OpentelemetryEcto.TestRepo,
   pool: Ecto.Adapters.SQL.Sandbox
 
 config :opentelemetry,
-  processors: [{:otel_batch_processor, %{scheduled_delay_ms: 1}}]
+  processors: [{:otel_simple_processor, %{}}]
diff --git a/instrumentation/opentelemetry_ecto/test/opentelemetry_ecto_test.exs b/instrumentation/opentelemetry_ecto/test/opentelemetry_ecto_test.exs
index 44d0aef..11be4f3 100644
--- a/instrumentation/opentelemetry_ecto/test/opentelemetry_ecto_test.exs
+++ b/instrumentation/opentelemetry_ecto/test/opentelemetry_ecto_test.exs
@@ -15,16 +15,7 @@ defmodule OpentelemetryEctoTest do
   end
 
   setup do
-    :application.stop(:opentelemetry)
-    :application.set_env(:opentelemetry, :tracer, :otel_tracer_default)
-
-    :application.set_env(:opentelemetry, :processors, [
-      {:otel_batch_processor, %{scheduled_delay_ms: 1}}
-    ])
-
-    :application.start(:opentelemetry)
-
-    :otel_batch_processor.set_exporter(:otel_exporter_pid, self())
+    :otel_simple_processor.set_exporter(:otel_exporter_pid, self())
 
     OpenTelemetry.Tracer.start_span("test")
 
diff --git a/instrumentation/opentelemetry_phoenix/config/test.exs b/instrumentation/opentelemetry_phoenix/config/test.exs
index a279b9d..28a095d 100644
--- a/instrumentation/opentelemetry_phoenix/config/test.exs
+++ b/instrumentation/opentelemetry_phoenix/config/test.exs
@@ -1,4 +1,4 @@
 import Config
 
 config :opentelemetry,
-  processors: [{:otel_batch_processor, %{scheduled_delay_ms: 1}}]
+  processors: [{:otel_simple_processor, %{}}]
diff --git a/instrumentation/opentelemetry_phoenix/test/opentelemetry_phoenix_test.exs b/instrumentation/opentelemetry_phoenix/test/opentelemetry_phoenix_test.exs
index 526d360..077c900 100644
--- a/instrumentation/opentelemetry_phoenix/test/opentelemetry_phoenix_test.exs
+++ b/instrumentation/opentelemetry_phoenix/test/opentelemetry_phoenix_test.exs
@@ -17,16 +17,8 @@ defmodule OpentelemetryPhoenixTest do
   end
 
   setup do
-    :application.stop(:opentelemetry)
-    :application.set_env(:opentelemetry, :tracer, :otel_tracer_default)
+    :otel_simple_processor.set_exporter(:otel_exporter_pid, self())
 
-    :application.set_env(:opentelemetry, :processors, [
-      {:otel_batch_processor, %{scheduled_delay_ms: 1}}
-    ])
-
-    :application.start(:opentelemetry)
-
-    :otel_batch_processor.set_exporter(:otel_exporter_pid, self())
     :ok
   end