spec: add tests to logging module (#7)

spec/mime_actor/logging_spec.rb

@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+require "mime_actor/logging"
+require "logger"
+
+RSpec.describe MimeActor::Logging do
+  let(:klazz) { Class.new.include described_class }
+  let(:klazz_instance) { klazz.new }
+  let(:stub_logger_class) { Class.new(Logger) }
+
+  describe "#logger" do
+    it "returns default logger" do
+      expect(klazz.logger).to be_present
+      expect(klazz.logger).to be_a(ActiveSupport::TaggedLogging)
+    end
+
+    it "allows reassignment" do
+      expect(klazz.logger).to be_present
+      klazz.logger = stub_logger_class.new($stdout)
+      expect(klazz.logger).to be_a(stub_logger_class)
+    end
+  end
+
+  describe "#config" do
+    it "allows configure" do
+      expect(klazz.logger).not_to be_a(stub_logger_class)
+      expect do
+        klazz.configure do |config|
+          config.logger = stub_logger_class.new($stdout)
+        end
+      end.not_to raise_error
+      expect(klazz.logger).to be_a(stub_logger_class)
+    end
+  end
+
+  describe "#fill_run_sheet" do
+    let(:log_formatter) { klazz.logger.formatter }
+
+    it "include default tag \"MimeActor\"" do
+      expect(log_formatter.current_tags).not_to include("MimeActor")
+      klazz_instance.send(:fill_run_sheet) do
+        expect(log_formatter.current_tags).to include("MimeActor")
+      end
+      expect(log_formatter.current_tags).not_to include("MimeActor")
+    end
+
+    it "allows tagging" do
+      expect(log_formatter.current_tags).not_to include("my_tag_a")
+      klazz_instance.send(:fill_run_sheet, "my_tag_a", "my_tag_b") do
+        expect(log_formatter.current_tags).to include("my_tag_a")
+        expect(log_formatter.current_tags).to include("my_tag_b")
+      end
+      expect(log_formatter.current_tags).not_to include("my_tag")
+    end
+  end
+end