Added additional output messages for Fish and Zsh users.

* Allow `print_completion_file`, `install_completion_file`, and
  `uninstall_completion_file` to be overridden.

lib/ronin/core/cli/completion_command.rb

@@ -134,18 +134,70 @@ def completion_file
         # Runs the `completion` command.
         #
         def run
+          if shell_type == :fish
+            print_error "shell completions for the fish shell are not currently supported"
+            exit(-1)
+          end
+
           case @mode
           when :print
-            print_completion_file(completion_file)
+            print_completion_file
           when :install
-            install_completion_file(completion_file)
+            install_completion_file
+
+            if shell_type == :zsh
+              puts "Ensure that you have the following lines added to your ~/.zshrc:"
+              puts
+              puts "    autoload -Uz +X compinit && compinit"
+              puts "    autoload -Uz +X bashcompinit && bashcompinit"
+              puts
+            end
           when :uninstall
-            uninstall_completion_file_for(File.basename(completion_file))
+            uninstall_completion_file
+
+            puts "Completion rules successfully uninstalled. Please restart your shell."
           else
             raise(NotImplementedError,"mode not implemented: #{@mode.inspect}")
           end
         end
 
+        #
+        # Prints the `completion` command's {completion_file} to stdout.
+        #
+        # @param [String] completion_file
+        #   The path to the completion file to print.
+        #
+        # @api private
+        #
+        def print_completion_file(completion_file=self.completion_file)
+          super(completion_file)
+        end
+
+        #
+        # Installs the `completion` command's {completion_file} for the current
+        # `SHELL`.
+        #
+        # @param [String] completion_file
+        #   The path to the completion file to install.
+        #
+        # @api private
+        #
+        def install_completion_file(completion_file=self.completion_file)
+          super(completion_file)
+        end
+
+        #
+        # Uninstalls the `completion` command's {completion_file}.
+        #
+        # @param [String] completion_file
+        #   The path to the completion file to uninstall.
+        #
+        # @api private
+        #
+        def uninstall_completion_file(completion_file=self.completion_file)
+          uninstall_completion_file_for(File.basename(completion_file))
+        end
+
       end
     end
   end

spec/cli/completion_command_spec.rb

@@ -120,7 +120,7 @@ class CommandWithCompletionFile < Ronin::Core::CLI::CompletionCommand
   describe "#run" do
     context "when no options are given" do
       it "must call #print_completion_file with #completion_file" do
-        expect(subject).to receive(:print_completion_file).with(subject.completion_file)
+        expect(subject).to receive(:print_completion_file).with(no_args)
 
         subject.run
       end
@@ -130,7 +130,7 @@ class CommandWithCompletionFile < Ronin::Core::CLI::CompletionCommand
       before { subject.option_parser.parse(%w[--print]) }
 
       it "must call #print_completion_file with #completion_file" do
-        expect(subject).to receive(:print_completion_file).with(subject.completion_file)
+        expect(subject).to receive(:print_completion_file).with(no_args)
 
         subject.run
       end
@@ -140,24 +140,70 @@ class CommandWithCompletionFile < Ronin::Core::CLI::CompletionCommand
       before { subject.option_parser.parse(%w[--install]) }
 
       it "must call #install_completion_file with #completion_file" do
-        expect(subject).to receive(:install_completion_file).with(subject.completion_file)
+        expect(subject).to receive(:install_completion_file).with(no_args)
 
         subject.run
       end
+
+      context "and the 'SHELL' is a zsh shell" do
+        let(:shell) { '/bin/zsh' }
+
+        subject do
+          command_class.new(env: {'SHELL' => shell})
+        end
+
+        it "must also print a message instructing the user to add additional configuration to their ~/.zshrc file to enable the installed bash completions" do
+          expect(subject).to receive(:install_completion_file).with(no_args)
+          expect(subject).to receive(:puts).with(
+            "Ensure that you have the following lines added to your ~/.zshrc:"
+          )
+          expect(subject).to receive(:puts).with(no_args)
+          expect(subject).to receive(:puts).with(
+            "    autoload -Uz +X compinit && compinit"
+          )
+          expect(subject).to receive(:puts).with(
+            "    autoload -Uz +X bashcompinit && bashcompinit"
+          )
+          expect(subject).to receive(:puts).with(no_args)
+
+          subject.run
+        end
+      end
     end
 
     context "when the --uninstall option is given" do
       before { subject.option_parser.parse(%w[--uninstall]) }
 
-      it "must call #uninstall_completion_file with the basename of the #completion_file" do
-        expect(subject).to receive(:uninstall_completion_file_for).with(
-          File.basename(subject.completion_file)
+      it "must call #uninstall_completion_file with the basename of the #completion_file and print a message instructing the user to restart their shell" do
+        expect(subject).to receive(:uninstall_completion_file).with(no_args)
+        expect(subject).to receive(:puts).with(
+          "Completion rules successfully uninstalled. Please restart your shell."
         )
 
         subject.run
       end
     end
 
+    context "when the 'SHELL' is a fish shell" do
+      let(:shell) { '/bin/fish' }
+
+      subject do
+        command_class.new(env: {'SHELL' => shell})
+      end
+
+      it "must print an error message about fish completions not being supported and exit with -1" do
+        expect(subject).to receive(:print_error).with(
+          "shell completions for the fish shell are not currently supported"
+        )
+
+        expect {
+          subject.run
+        }.to raise_error(SystemExit) { |error|
+          expect(error.status).to eq(-1)
+        }
+      end
+    end
+
     context "when #mode is neither :print, :install, or :uninstall" do
       let(:mode) { :foo }