Implements gel env command

lib/gel/command/env.rb

@@ -2,6 +2,109 @@
 
 class Gel::Command::Env < Gel::Command
   def run(command_line)
-    raise "TODO"
+    option = { full: (command_line.shift == "--full") }
+    data = metadata(option)
+    MarkdownFormatter.format(data)
+  end
+
+  private
+
+  def metadata(option)
+    metadata = {
+      "Gel" => gel_envs,
+      "User" => user_envs,
+      "Ruby" => ruby_envs,
+    }
+    if option[:full]
+      metadata.merge!("Relevant Files" => RELEVANT_FILES)
+    end
+    metadata
+  end
+
+  module MarkdownFormatter
+    def self.format(data)
+      data.each do |section, value_hash|
+        puts "\n## #{section}"
+        value_hash.reject { |_, v| v.nil? }.each do |name, value|
+
+          if value.is_a?(RelevantFile)
+            print_codeblock(name, value)
+          else
+            print_code_in_list(name, value)
+          end
+        end
+      end
+    end
+
+    def self.print_code_in_list(name, value)
+      if !value.empty?
+        puts "- `#{name}`: `#{value}`"
+      end
+    end
+
+    def self.print_codeblock(name, content)
+      puts "`#{name}`"
+      puts "\n```"
+      puts content
+      puts "```\n"
+    end
+  end
+  private_constant :MarkdownFormatter
+
+  USER_HOME = begin
+    require "etc"
+    File.expand_path(Dir.home(Etc.getlogin))
+  end
+  private_constant :USER_HOME
+
+  class RelevantFile
+    def initialize(path)
+      @path = path
+    end
+
+    def to_s
+      IO.read(path)
+    end
+
+    private
+    attr_reader :path
+  end
+  private_constant :RelevantFile
+
+  RELEVANT_FILES = Dir[
+    "#{USER_HOME}/.config/gel/config",
+    "Gemfile",
+    "Gemfile.lock",
+    "*.gemspec",
+  ].map { |path| [path, RelevantFile.new(path)] }.to_h
+  private_constant :RELEVANT_FILES
+
+  def env_fetch(key, fallback = nil)
+    ENV.fetch(key) { fallback }
+  end
+
+  def gel_envs
+    {
+      "GEL_VERSION": Gel::VERSION,
+    }
+  end
+
+  def user_envs
+    {
+      SHELL: env_fetch("SHELL"),
+    }
+  end
+
+  def ruby_envs
+    {
+      GEM_HOME: env_fetch("GEM_HOME"),
+      GEM_PATH: env_fetch("GEM_PATH"),
+      GEM_ROOT: env_fetch("GEM_ROOT"),
+      RUBY_ENGINE: env_fetch("RUBY_ENGINE"),
+      RUBY_ENGINE_VERSION: env_fetch("RUBY_ENGINE_VERSION", RUBY_ENGINE_VERSION),
+      RUBYOPT: env_fetch("RUBYOPT"),
+      RUBY_ROOT: env_fetch("RUBY_ROOT"),
+      RUBY_VERSION: env_fetch("RUBY_VERSION", RUBY_VERSION),
+    }
   end
 end

test/command/env_test.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+class EnvTest < Minitest::Test
+  def test_env
+    output = capture_stdout { Gel::Command::Env.run(["env"]) }
+
+    assert output =~ %r{## Gel}
+    assert output =~ %r{## User}
+    assert output =~ %r{## Ruby}
+  end
+
+  def test_env_with_full
+    output = capture_stdout { Gel::Command::Env.run(["env", "--full"]) }
+
+    assert output =~ %r{## Gel}
+    assert output =~ %r{## User}
+    assert output =~ %r{## Ruby}
+    assert output =~ %r{## Relevant Files}
+  end
+end