Global error handler

exe/3scale

@@ -4,4 +4,4 @@ require '3scale_toolbox'
 
 args = ARGV.clone
 
-ThreeScaleToolbox::CLI.run args
+exit(ThreeScaleToolbox::CLI.run(args))

lib/3scale_toolbox/cli.rb

@@ -1,3 +1,5 @@
+require '3scale_toolbox/cli/error_handler'
+
 module ThreeScaleToolbox::CLI
   def self.root_command
     ThreeScaleToolbox::Commands::ThreeScaleCommand
@@ -11,10 +13,31 @@ def self.load_builtin_commands
     ThreeScaleToolbox::Commands::BUILTIN_COMMANDS.each(&method(:add_command))
   end
 
+  def self.install_signal_handlers
+    # Set exit handler
+    %w[INT TERM].each do |signal|
+      Signal.trap(signal) do
+        puts
+        exit!(0)
+      end
+    end
+
+    # Set stack trace dump handler
+    if !defined?(RUBY_ENGINE) || RUBY_ENGINE != 'jruby'
+      Signal.trap('USR1') do
+        puts 'Caught USR1; dumping a stack trace'
+        puts caller.map { |i| "  #{i}" }.join("\n")
+      end
+    end
+  end
+
   def self.run(args)
-    load_builtin_commands
-    ThreeScaleToolbox.load_plugins
-    # TODO handle error
-    root_command.build_command.run args
+    install_signal_handlers
+    err = ErrorHandler.error_watchdog do
+      load_builtin_commands
+      ThreeScaleToolbox.load_plugins
+      root_command.build_command.run args
+    end
+    err.nil? ? 0 : 1
   end
 end

lib/3scale_toolbox/cli/error_handler.rb

@@ -0,0 +1,120 @@
+require 'json'
+
+module ThreeScaleToolbox
+  module CLI
+    class ErrorHandler
+      def self.error_watchdog
+        new.error_watchdog { yield }
+      end
+
+      # Catches errors and prints nice diagnostic messages
+      def error_watchdog
+        # Run
+        yield
+      rescue StandardError, ScriptError => e
+        handle_error e
+        e
+      else
+        nil
+      end
+
+      private
+
+      def handle_error(error)
+        if expected_error?(error)
+          warn
+          warn "\e[1m\e[31mError: #{error.message}\e[0m"
+        else
+          print_error(error)
+        end
+      end
+
+      def expected_error?(error)
+        case error
+        when ThreeScaleToolbox::Error
+          true
+        else
+          false
+        end
+      end
+
+      def print_error(error)
+        write_error(error, $stderr)
+
+        File.open('crash.log', 'w') do |io|
+          write_verbose_error(error, io)
+        end
+
+        write_section_header($stderr, 'Detailed information')
+        warn
+        warn 'A detailed crash log has been written to ./crash.log.'
+      end
+
+      def write_error(error, stream)
+        write_error_message(error, stream)
+        write_stack_trace(error, stream)
+      end
+
+      def write_error_message(error, stream)
+        write_section_header(stream, 'Message')
+        stream.puts "\e[1m\e[31m#{error.class}: #{error.message}\e[0m"
+      end
+
+      def write_stack_trace(error, stream)
+        write_section_header(stream, 'Backtrace')
+        stream.puts error.backtrace
+      end
+
+      def write_version_information(stream)
+        write_section_header(stream, 'Version Information')
+        stream.puts ThreeScaleToolbox::VERSION
+      end
+
+      def write_system_information(stream)
+        write_section_header(stream, 'System Information')
+        stream.puts Etc.uname.to_json
+      end
+
+      def write_installed_gems(stream)
+        write_section_header(stream, 'Installed gems')
+        gems_and_versions.each do |g|
+          stream.puts "  #{g.first} #{g.last.join(', ')}"
+        end
+      end
+
+      def write_load_paths(stream)
+        write_section_header(stream, 'Load paths')
+        $LOAD_PATH.each_with_index do |i, index|
+          stream.puts "  #{index}. #{i}"
+        end
+      end
+
+      def write_verbose_error(error, stream)
+        stream.puts "Crashlog created at #{Time.now}"
+
+        write_error_message(error, stream)
+        write_stack_trace(error, stream)
+        write_version_information(stream)
+        write_system_information(stream)
+        write_installed_gems(stream)
+        write_load_paths(stream)
+      end
+
+      def gems_and_versions
+        gems = {}
+        Gem::Specification.find_all.sort_by { |s| [s.name, s.version] }.each do |spec|
+          gems[spec.name] ||= []
+          gems[spec.name] << spec.version.to_s
+        end
+        gems
+      end
+
+      def write_section_header(stream, title)
+        stream.puts
+
+        stream.puts "===== #{title.upcase}:"
+        stream.puts
+      end
+    end
+  end
+end

spec/unit/error_handler_spec.rb

@@ -0,0 +1,55 @@
+require '3scale_toolbox'
+
+RSpec.describe ThreeScaleToolbox::CLI::ErrorHandler do
+  include_context :temp_dir
+
+  context '#error_watchdog' do
+    def raise_runtime_error
+      raise 'some error'
+    end
+
+    def raise_toolbox_error
+      raise ThreeScaleToolbox::Error, 'some error'
+    end
+
+    context 'raises expected error' do
+      it 'error is shown on stderr' do
+        Dir.chdir(tmp_dir) do
+          expect do
+            subject.error_watchdog { raise_toolbox_error }
+          end.to output(/some error/).to_stderr
+          expect(File).not_to exist('crash.log')
+        end
+      end
+
+      it 'returns error' do
+        expect(
+          subject.error_watchdog { raise_toolbox_error }
+        ).to be
+      end
+    end
+
+    context 'raises unexpected error' do
+      it 'crash.log is generated' do
+        Dir.chdir(tmp_dir) do
+          expect do
+            subject.error_watchdog { raise_runtime_error }
+          end.to output(/some error/).to_stderr
+          expect(File).to exist('crash.log')
+        end
+      end
+
+      it 'returns error' do
+        expect(
+          subject.error_watchdog { raise_runtime_error }
+        ).to be
+      end
+    end
+
+    context 'Does not raise error' do
+      it 'returns true' do
+        expect(subject.error_watchdog {}).to be_nil
+      end
+    end
+  end
+end