Adds new Plugin loader to load native plugin files

Author: codenamev

lib/git_commander/loader_result.rb

@@ -3,11 +3,12 @@
 module GitCommander
   # @abstract A simple object to wrap errors loading any given loader
   class LoaderResult
-    attr_accessor :commands, :errors
+    attr_accessor :commands, :plugins, :errors
 
     def initialize
       @errors = []
       @commands = []
+      @plugins = []
     end
 
     def success?

lib/git_commander/plugin/loader.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+require "bundler/inline"
+require_relative "../loader"
+
+module GitCommander
+  class Plugin
+    # @abstract Handles loading native plugins by name.
+    class Loader < ::GitCommander::Loader
+      class NotFoundError < StandardError; end
+      class LoadError < StandardError; end
+
+      NATIVE_PLUGIN_DIR = File.expand_path(File.join(__dir__, "..", "plugins"))
+
+      attr_reader :content
+
+      def load(name)
+        @content = File.read("#{NATIVE_PLUGIN_DIR}/#{name}.rb")
+        result.plugins << GitCommander::Plugin.new(name.to_sym, source_instance: instance_eval(@content))
+        result
+      rescue Errno::ENOENT => e
+        handle_error LoadError, e
+      rescue StandardError => e
+        handle_error NotFoundError, e
+      end
+
+      private
+
+      def handle_error(error_klass, original_error)
+        error = error_klass.new(original_error.message)
+        error.set_backtrace original_error.backtrace
+        @result.errors << error
+        @result
+      end
+    end
+  end
+end

spec/lib/git_commander/plugin/loader_spec.rb

@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+RSpec.describe GitCommander::Plugin::Loader do
+  let(:registry) { GitCommander::Registry.new }
+  let(:loader) { described_class.new(registry) }
+
+  describe ".load(name, path:, url:)" do
+    it "returns a Result" do
+      expect(loader.load(:git)).to be_a GitCommander::LoaderResult
+    end
+
+    it "loads the plugins result with matching native plugin" do
+      result = loader.load(:git)
+
+      expect(result).to be_success
+
+      plugin = result.plugins.first
+      expect(plugin.name).to eq :git
+      expect(plugin.executor).to respond_to(:branches)
+    end
+
+    it "reports NotFound if the native plugin doesn't exist" do
+      result = loader.load(:bubbles)
+
+      expect(result).to_not be_success
+
+      resulting_error = result.errors.first
+      expect(resulting_error).to be_kind_of described_class::LoadError
+      expect(resulting_error.message).to include "No such file or directory"
+      expect(resulting_error.backtrace).to_not be_empty
+    end
+
+    it "reports LoadError if there's a problem reading the native plugin" do
+      allow(File).to receive(:read).and_raise Errno::EACCES
+      result = loader.load(:bubbles)
+
+      expect(result).to_not be_success
+
+      resulting_error = result.errors.first
+      expect(resulting_error).to be_kind_of described_class::NotFoundError
+      expect(resulting_error.message).to include "Permission denied"
+      expect(resulting_error.backtrace).to_not be_empty
+    end
+  end
+end