CI: run Credo in strict mode

Exclude test files from AliasUsage check in .credo.exs.
Use mix credo --strict in Justfile and .drone.yml.

.credo.exs

@@ -82,8 +82,14 @@
           # You can customize the priority of any check
           # Priority values are: `low, normal, high, higher`
           #
+          # AliasUsage only for lib and support; test files excluded (many nested module refs by design)
           {Credo.Check.Design.AliasUsage,
-           [priority: :low, if_nested_deeper_than: 2, if_called_more_often_than: 0]},
+           [
+             priority: :low,
+             if_nested_deeper_than: 2,
+             if_called_more_often_than: 0,
+             files: %{excluded: ["test/"]}
+           ]},
           {Credo.Check.Design.TagFIXME, []},
           # You can also customize the exit_status of each check.
           # If you don't want TODO comments to cause `mix credo` to fail, just

.drone.yml

@@ -52,7 +52,7 @@ steps:
       # Check for dependencies that are not maintained anymore
       - mix hex.audit
       # Provide hints for improving code quality
-      - mix credo
+      - mix credo --strict
       # Check that translations are up to date
       - mix gettext.extract --check-up-to-date
 
@@ -159,7 +159,7 @@ steps:
       # Check for dependencies that are not maintained anymore
       - mix hex.audit
       # Provide hints for improving code quality
-      - mix credo
+      - mix credo --strict
       # Check that translations are up to date
       - mix gettext.extract --check-up-to-date
 

Justfile

@@ -31,7 +31,7 @@ gettext:
 lint:
     mix format --check-formatted
     mix compile --warnings-as-errors
-    mix credo
+    mix credo --strict
     # Check that all German translations are filled (UI must be in German)
     @bash -c 'for file in priv/gettext/de/LC_MESSAGES/*.po; do awk "/^msgid \"\"$/{header=1; next} /^msgid /{header=0} /^msgstr \"\"$/ && !header{print FILENAME\":\"NR\": \" \$0; exit 1}" "$file" || exit 1; done'
     mix gettext.extract --check-up-to-date