From f2f097e9ca8ad2fa8bb30ee508242d4d4388e91c Mon Sep 17 00:00:00 2001
From: Aleksei Matiushkin <am@ambment.cat>
Date: Tue, 3 Dec 2024 06:54:22 +0100
Subject: [PATCH] Better handling of the wrong config for messenger

---
 examples/tm/config/config.exs |  7 ++++---
 lib/telemetria/messenger.ex   | 29 +++++++++++++++++++++++++++++
 mix.exs                       |  2 +-
 3 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/examples/tm/config/config.exs b/examples/tm/config/config.exs
index 4fb5165..31c9239 100644
--- a/examples/tm/config/config.exs
+++ b/examples/tm/config/config.exs
@@ -6,6 +6,7 @@ config :telemetria,
   events: [
     [:tm, :f_to_c]
   ],
-  throttle: %{some_group: {1_000, :last}},
-  # create a slack app and put URL here
-  messenger_channels: %{slack: {:slack, url: ""}}
+  throttle: %{some_group: {1_000, :last}}
+
+# create a slack app and put URL here
+# messenger_channels: %{slack: {:slack, url: ""}}
diff --git a/lib/telemetria/messenger.ex b/lib/telemetria/messenger.ex
index 708f9a7..697fde3 100644
--- a/lib/telemetria/messenger.ex
+++ b/lib/telemetria/messenger.ex
@@ -41,6 +41,35 @@ defmodule Telemetria.Messenger do
         else: inspect(message, opts)
 
     do_post(message, impl, opts)
+  rescue
+    e in KeyError ->
+      require Logger
+
+      message =
+        """
+        One or more required options were missing for the call to the messenger implementation
+        in `telemetría` module attribute (or global config.)
+
+        For now this is rescued and application can continue, but messenging from telemetria won’t work.
+
+        Error: #{e.message}.
+        """
+
+      Logger.error(message)
+
+    e in RuntimeError ->
+      require Logger
+
+      message =
+        """
+        The unexpected runtime error occured. Usually it means the config in `runtime.exs`
+        is diverged from what `telemetría` compliler saw. Please move all the config to the
+        compile-time configurations files since `telemetría` needs them during a compilation stage.
+
+        Error: #{e.message}
+        """
+
+      Logger.error(message)
   end
 
   def post(message, impl, opts) when is_binary(message),
diff --git a/mix.exs b/mix.exs
index 04311a1..6180e65 100644
--- a/mix.exs
+++ b/mix.exs
@@ -2,7 +2,7 @@ defmodule Telemetria.MixProject do
   use Mix.Project
 
   @app :telemetria
-  @version "0.21.1"
+  @version "0.21.2"
 
   def project do
     [