1 files changed, 83 insertions, 0 deletions
diff --git a/lib/rubygems/commands/open_command.rb b/lib/rubygems/commands/open_command.rb
new file mode 100644
index 0000000000..0fe90dc8b8
--- /dev/null
+++ b/lib/rubygems/commands/open_command.rb
@@ -0,0 +1,83 @@
+# frozen_string_literal: true
+
+require_relative "../command"
+require_relative "../version_option"
+
+class Gem::Commands::OpenCommand < Gem::Command
+  include Gem::VersionOption
+
+  def initialize
+    super "open", "Open gem sources in editor"
+
+    add_option("-e", "--editor COMMAND", String,
+               "Prepends COMMAND to gem path. Could be used to specify editor.") do |command, options|
+      options[:editor] = command || get_env_editor
+    end
+    add_option("-v", "--version VERSION", String,
+               "Opens specific gem version") do |version|
+      options[:version] = version
+    end
+  end
+
+  def arguments # :nodoc:
+    "GEMNAME     name of gem to open in editor"
+  end
+
+  def defaults_str # :nodoc:
+    "-e #{get_env_editor}"
+  end
+
+  def description # :nodoc:
+    <<-EOF
+        The open command opens gem in editor and changes current path
+        to gem's source directory.
+        Editor command can be specified with -e option, otherwise rubygems
+        will look for editor in $EDITOR, $VISUAL and $GEM_EDITOR variables.
+    EOF
+  end
+
+  def usage # :nodoc:
+    "#{program_name} [-e COMMAND] GEMNAME"
+  end
+
+  def get_env_editor
+    ENV["GEM_EDITOR"] ||
+      ENV["VISUAL"] ||
+      ENV["EDITOR"] ||
+      "vi"
+  end
+
+  def execute
+    @version = options[:version] || Gem::Requirement.default
+    @editor  = options[:editor] || get_env_editor
+
+    found = open_gem(get_one_gem_name)
+
+    terminate_interaction 1 unless found
+  end
+
+  def open_gem(name)
+    spec = spec_for name
+
+    return false unless spec
+
+    if spec.default_gem?
+      say "'#{name}' is a default gem and can't be opened."
+      return false
+    end
+
+    open_editor(spec.full_gem_path)
+  end
+
+  def open_editor(path)
+    system(*@editor.split(/\s+/) + [path], { chdir: path })
+  end
+
+  def spec_for(name)
+    spec = Gem::Specification.find_all_by_name(name, @version).first
+
+    return spec if spec
+
+    say "Unable to find gem '#{name}'"
+  end
+end