Increase test coverage for Lotus::Config::Mapper

test/config/mapper_test.rb

@@ -0,0 +1,39 @@
+require 'test_helper'
+
+describe Lotus::Config::Mapper do
+  describe '#to_proc' do
+    describe 'when only path is given' do
+      before do
+        @mapping = Lotus::Config::Mapper.new(path)
+      end
+
+      describe "and it's nil" do
+        let(:path) { nil }
+
+        it 'raises error' do
+          assert_raises ArgumentError do
+            @mapping.to_proc
+          end
+        end
+      end
+
+      describe "and it points to an unknown file" do
+        let(:path) { 'unknown/path' }
+
+        it 'raises error' do
+          assert_raises ArgumentError do
+            @mapping.to_proc
+          end
+        end
+      end
+
+      describe "and it points to a valid file" do
+        let(:path) { __dir__ + '/../fixtures/mapper' }
+
+        it 'raises error' do
+          assert_kind_of Proc, @mapping.to_proc
+        end
+      end
+    end
+  end
+end

test/fixtures/mapper.rb

@@ -0,0 +1 @@
+puts 'hi'