require_relative 'config/environment'
HTTP_ERRORS = [
RestClient::Exception
]
module API
class Client
def initialize
#client = RawClient.new
end
def search(params = {})
call { #client.search(params) }
end
def call
raise 'No block specified' unless block_given?
loop do # Keep retrying on error
begin
return yield
rescue *HTTP_ERRORS => e
puts "#{e.response&.request.url}"
sleep 5
end
end
end
end
class RawClient
BASE_URL = 'https://www.google.com'
def search(params = {})
go "search/#{params.delete(:query)}", params
end
private
def go(path, params = {})
RestClient.get(BASE_URL + '/' + path, params: params)
end
end
end
API::Client.new.search(query: 'tulips', per_page: 10)
Will output
https://www.google.com/search/tulips?per_page=10 # First time
https://www.google.com/search/?per_page=10 # On retry
I thought I was being clever here: have a flexible and unified way to pass parameters (ie. search(query: 'tulips', per_page: 10)) and let the client implementation figure out what goes into the url itself (ie. query) and what should be passed as GET parameters (ie. per_page).
But the query param is lost from the params after the first retry, because the hash is passed by reference and delete makes a permanent change to it. The second time yield is called, it apparently preserves the context and params won't have the deleted query anymore in it.
What would be an elegant way to solve this? Doing call { #client.search(params.dup) } seems a bit excessive.
Sometimes backtrace is enough to diagnose problem. But sometimes reason of crash is not obvious without knowledge what was passed to function.
Getting information what was passed to function that caused crash would be quite useful, especially in cases where reproducing is not obvious because it was caused by for example exception in network connection, weird user input or because program is depends on randomisation or processes data from external sensor.
Lets say that there is following program
def handle_changed_input(changed_input)
raise 'ops' if changed_input =~ /magic/
end
def do_something_with_user_input(input)
input = "#{input.strip}c"
handle_changed_input(input)
end
input = gets
do_something_with_user_input(input)
where user typed "magic" as input. Normally one has
test.rb:2:in `handle_changed_input': ops (RuntimeError)
from test.rb:7:in `do_something_with_user_input'
from test.rb:11:in `<main>'
as output. What one may do to show also what was passed to function? Something like
test.rb:2:in `handle_changed_input("magic")': ops (RuntimeError)
from test.rb:7:in `do_something_with_user_input("magi\n")'
from test.rb:11:in `<main>'
It would be useful in many situations (and not truly useful where parameters are not representable as strings of reasonable legth, there is a good reason why it is not enabled by default).
How one may add this functionality? It is necessary that program works as usually during normal operation and preferably there is no additional output before crash.
I tried for example
def do_something_with_user_input(input)
method(__method__).parameters.map do |_, name|
puts "#{name}=#{binding.local_variable_get(name)}"
end
raise 'ops' if input =~ /magic/
end
input = gets
found in Is there a way to access method arguments in Ruby? but it would print on every single entrance to function what both would flood output and make program significantly slower.
I don't have a complete solution but... But you can get method arguments of all called methods in controlled environment with TracePoint class from Ruby core lib.
Look at the example:
trace = TracePoint.new(:call) do |tp|
puts "===================== #{tp.method_id}"
b_self = tp.binding.eval('self')
names = b_self.method(tp.method_id).parameters.map(&:last)
values = names.map { |name| tp.binding.eval(name.to_s) }
p names.zip(values)
end
trace.enable
def method_a(p1, p2, p3)
end
method_a(1, "foobar", false)
#=> ===================== method_a
#=> [[:p1, 1], [:p2, "foobar"], [:p3, false]]
To print exception backtraces, Ruby uses the C function exc_backtrace from error.c (exc_backtrace on github). Unless you patch Ruby with the functionality you need, I don't think there a way to change exception backtrace outputs.
Here is a snippet (trace.rb) you might find useful:
set_trace_func -> (event, file, line, id, binding, classname) do
if event == 'call' && meth = binding.eval('__method__')
params = binding.method(meth).parameters.select{|e| e[0] != :block}
values = params.map{|_, var| [var, binding.local_variable_get(var)]}
printf "%8s %s:%-2d %15s %8s %s\n", event, file, line, id, classname, values.inspect
else
printf "%8s %s:%-2d %15s %8s\n", event, file, line, id, classname
end
end
def foo(a,b = 0)
bar(a, foo: true)
end
def bar(c, d = {})
puts "!!!buz!!!\n"
end
foo('lol')
The output of that snippet is:
c-return /path/to/trace.rb:1 set_trace_func Kernel
line /path/to/trace.rb:12
c-call /path/to/trace.rb:12 method_added Module
c-return /path/to/trace.rb:12 method_added Module
line /path/to/trace.rb:16
c-call /path/to/trace.rb:16 method_added Module
c-return /path/to/trace.rb:16 method_added Module
line /path/to/trace.rb:20
call /path/to/trace.rb:12 foo Object [[:a, "lol"], [:b, 0]]
line /path/to/trace.rb:13 foo Object
call /path/to/trace.rb:16 bar Object [[:c, "lol"], [:d, {:foo=>true}]]
line /path/to/trace.rb:17 bar Object
c-call /path/to/trace.rb:17 puts Kernel
c-call /path/to/trace.rb:17 puts IO
c-call /path/to/trace.rb:17 write IO
!!!buz!!!
c-return /path/to/trace.rb:17 write IO
c-return /path/to/trace.rb:17 puts IO
c-return /path/to/trace.rb:17 puts Kernel
return /path/to/trace.rb:18 bar Object
return /path/to/trace.rb:14 foo Object
I hope that helps you as much as it helped me.
I think that it is possible. The code below is not perfect and would require some additional work, but it caputers the primary idea of a stacktrace with argument values. Please note, that in order to know the call site, I am zipping the original stacktrace with the entry sites catched by trace function. To distinguishe these entries I use '>' and '<' respectively.
class Reporting
def self.info(arg1)
puts "*** #{arg1} ***"
end
end
def read_byte(arg1)
Reporting.info(arg1)
raise Exception.new("File not found")
end
def read_input(arg1)
read_byte(arg1)
end
def main(arg1)
read_input(arg1)
end
class BetterStacktrace
def self.enable
set_trace_func -> (event, file, line, id, binding, classname) do
case event
when 'call'
receiver_type = binding.eval('self.class')
if receiver_type == Object
meth = binding.eval('__method__')
params = binding.method(meth).parameters.select{|e| e[0] != :block}
values = params.map{|_, var| [var, binding.local_variable_get(var)]}
self.push(event, file, line, id, classname, values)
else
self.push(event, file, line, id, classname)
end
when 'return'
self.pop
when 'raise'
self.push(event, file, line, id, classname)
Thread.current[:_keep_stacktrace] = true
end
end
end
def self.push(event, file, line, id, classname, values=nil)
Thread.current[:_saved_stacktrace] = [] unless Thread.current.key?(:_saved_stacktrace)
unless Thread.current[:_keep_stacktrace]
if values
values_msg = values.map(&:last).join(", ")
msg = "%s:%d:in `%s(%s)'" % [file, line, id, values_msg]
else
msg = "%s:%d:in `%s'" % [file, line, id]
end
Thread.current[:_saved_stacktrace] << msg
end
end
def self.pop()
Thread.current[:_saved_stacktrace] = [] unless Thread.current.key?(:_saved_stacktrace)
unless Thread.current[:_keep_stacktrace]
value = Thread.current[:_saved_stacktrace].pop
end
end
def self.disable
set_trace_func nil
end
def self.print_stacktrace(calls)
enters = Thread.current[:_saved_stacktrace].reverse
calls.zip(enters).each do |call, enter|
STDERR.puts "> #{enter}"
STDERR.puts "< #{call}"
end
Thread.current[:_saved_stacktrace] = []
end
end
BetterStacktrace.enable
begin
main(10)
rescue Exception => ex
puts "--- Catched ---"
puts ex
BetterStacktrace.print_stacktrace(ex.backtrace)
end
BetterStacktrace.disable
begin
main(10)
rescue Exception
puts "--- Catched ---"
puts ex
puts ex.backtrace
end
The output of the above code is as follows:
*** 10 ***
--- Catched ---
File not found
> work/tracing_with_params.rb:10:in `read_byte'
< work/tracing_with_params.rb:10:in `read_byte'
> work/tracing_with_params.rb:8:in `read_byte(10)'
< work/tracing_with_params.rb:14:in `read_input'
> work/tracing_with_params.rb:13:in `read_input(10)'
< work/tracing_with_params.rb:18:in `main'
> work/tracing_with_params.rb:17:in `main(10)'
< work/tracing_with_params.rb:82:in `<main>'
*** 10 ***
--- Catched ---
File not found
work/tracing_with_params.rb:10:in `read_byte'
work/tracing_with_params.rb:14:in `read_input'
work/tracing_with_params.rb:18:in `main'
work/tracing_with_params.rb:82:in `<main>'
EDIT:
The calls to class functions are not recorded. This has to be fixed in order for the stacktrace printing function not to get invalid output.
Moreover I used the STDERR as output to easily get one or the other output. You can change it if you wish.
MAX_STACK_SIZE = 200
tracer = proc do |event|
if event == 'call' && caller_locations.length > MAX_STACK_SIZE
fail "Probable Stack Overflow"
end
end
set_trace_func(tracer)
I kept running to this unexpected error token. I wanted the program to run without invoking ruby. For instances, instead of ruby program1.rb, i should be able to program1.rb poem.txt.
This is the error message:
program1.rb --backwards poem.txt
./program1.rb: line 1: syntax error near unexpected token `('
./program1.rb: line 1: `def backlines(line_array)'
This is my code:
def backlines(*line_array)
end
def backwards(line_array)
end
def backchars(line_array)
end
def main
file = File.new(ARGV[1], "r") do |file|
line_array = file.readlines
*line_array = line_array.reverse
if ARGV[0] == "--backlines"
*backwards_poem = backlines(line-array)
#you can manipulate "backwards_poem" however you want
elsif ARGV[0] == "--backwards"
backwards(line_array)
elsif ARGV[0] == "--backchars"
backchars(line_Array)
end
# passing a *line_array into a function
end
main
Have you executed ruby in your script at the top? eg:
#!/usr/bin/ruby
#!/usr/bin/ruby
def backlines(*line_array)
end
def backwards(line_array)
end
def backchars(line_array)
end
def main
puts ARGV
# File open not new ... this block requires the end below.
File.open(ARGV[1], "r") do |file|
line_array = file.readlines
*line_array = line_array.reverse
if ARGV[0] == "--backlines"
*backwards_poem = backlines(line_array)
#you can manipulate "backwards_poem" however you want
elsif ARGV[0] == "--backwards"
backwards(line_array)
elsif ARGV[0] == "--backchars"
backchars(line_array)
end
end
# passing a *line_array into a function
end
this should start you off if your call it like ./program1.rb --backwards file
you also had line-array , line_array and line_Array which should al be one variable i think.
I'm picking up ruby language and get stuck at playing with the chatterbot i have developed. Similar issue has been asked here Click here , I did what they suggested to change the rescue in order to see the full message.But it doesn't seem right, I was running basic_client.rb at rubybot directory and fred.bot is also generated at that directory . Please see the error message below: Your help very be very much appreciated.
Snailwalkers-MacBook-Pro:~ snailwalker$ cd rubybot
Snailwalkers-MacBook-Pro:rubybot snailwalker$ ruby basic_client.rb
/Users/snailwalker/rubybot/bot.rb:12:in `rescue in initialize': Can't load bot data because: No such file or directory - bot_data (RuntimeError)
from /Users/snailwalker/rubybot/bot.rb:9:in `initialize'
from basic_client.rb:3:in `new'
from basic_client.rb:3:in `<main>'
basic_client.rb
require_relative 'bot.rb'
bot = Bot.new(:name => 'Fred', :data_file => 'fred.bot')
puts bot.greeting
while input = gets and input.chomp != 'end'
puts '>> ' + bot.response_to(input)
end
puts bot.farewell
bot.rb:
require 'yaml'
require './wordplay'
class Bot
attr_reader :name
def initialize(options)
#name = options[:name] || "Unnamed Bot"
begin
#data = YAML.load(File.read('bot_data'))
rescue => e
raise "Can't load bot data because: #{e}"
end
end
def greeting
random_response :greeting
end
def farewell
random_response :farewell
end
def response_to(input)
prepared_input = preprocess(input).downcase
sentence = best_sentence(prepared_input)
reversed_sentence = WordPlay.switch_pronouns(sentence)
responses = possible_responses(sentence)
responses[rand(responses.length)]
end
private
def possible_responses(sentence)
responses = []
#data[:responses].keys.each do |pattern|
next unless pattern.is_a?(String)
if sentence.match('\b' + pattern.gsub(/\*/, '') + '\b')
if pattern.include?('*')
responses << #data[:responses][pattern].collect do |phrase|
matching_section = sentence.sub(/^.*#{pattern}\s+/, '')
phrase.sub('*', WordPlay.switch_pronouns(matching_section))
end
else
responses << #data[:responses][pattern]
end
end
end
responses << #data[:responses][:default] if responses.empty?
responses.flatten
end
def preprocess(input)
perform_substitutions input
end
def perform_substitutions(input)
#data[:presubs].each {|s| input.gsub!(s[0], s[1])}
input
end
# select best_sentence by looking at longest sentence
def best_sentence(input)
hot_words = #data[:responses].keys.select do |k|
k.class == String && k =~ /^\w+$/
end
WordPlay.best_sentence(input.sentences, hot_words)
end
def random_response(key)
random_index = rand(#data[:responses][key].length)
#data[:responses][key][random_index].gsub(/\[name\]/, #name)
end
end
I'm assuming that you are trying to load the :data_file passed into Bot.new, but right now you are statically loading a bot_data file everytime. You never mentioned about bot_data in the question. So if I'm right it should be like this :
#data = YAML.load(File.read(options[:data_file]))
Instead of :
#data = YAML.load(File.read('bot_data'))
I'm having trouble understanding how to test for output with puts. I need to know what I need to do in my RSPEC file.
This is my RSPEC file:
require 'game_io'
require 'board'
describe GameIO do
before(:each) do
#gameio = GameIO.new
#board = Board.new
end
context 'welcome_message' do
it 'should display a welcome message' do
test_in = StringIO.new("some test input\n")
test_out = StringIO.new
test_io = GameIO.new(test_in, test_out)
test_io.welcome_message
test_io.game_output.string.should == "Hey, welcome to my game. Get ready to be defeated"
end
end
end
This is the file it is testing against:
class GameIO
attr_reader :game_input, :game_output
def initialize(game_input = $stdin, game_output = $stdout)
#stdin = game_input
#stdout = game_output
end
def welcome_message
output "Hey, welcome to my game. Get ready to be defeated"
end
def output(msg)
#stdout.puts msg
end
def input
#stdin.gets
end
end
NOTE: I updated my RSPEC code to reflect changes I made to my test file given suggestions found elsewhere. To resolve the poblem completly I used the changes suggested by Chris Heald in my main file. Thank you all and thank you Chris.
Your initializer should be:
def initialize(game_input = $stdin, game_output = $stdout)
#game_input = game_input
#game_output = game_output
end
The reason for this is that attr_accessor generates methods like this:
# attr_accessor :game_output
def game_output
#game_output
end
def game_output=(output)
#game_output = output
end
(attr_reader generates only the reader method)
Thus, since you never assign #game_output, your game_output method will always return nil.
Just check you are sending it the message:
#gameio.should_receive(:puts).with("Hey, welcome to my game. Get ready to be defeated")
You could stub puts and print.
Perhaps the most fundamental way is to temporarily reassign STDOUT to a variable, and confirm the variable matches what you expect for output.
And Minitest has must_output as an assertion/spec.
The code is thus:
##
# Fails if stdout or stderr do not output the expected results.
# Pass in nil if you don't care about that streams output. Pass in
# "" if you require it to be silent. Pass in a regexp if you want
# to pattern match.
#
# NOTE: this uses #capture_io, not #capture_subprocess_io.
#
# See also: #assert_silent
def assert_output stdout = nil, stderr = nil
out, err = capture_io do
yield
end
err_msg = Regexp === stderr ? :assert_match : :assert_equal if stderr
out_msg = Regexp === stdout ? :assert_match : :assert_equal if stdout
y = send err_msg, stderr, err, "In stderr" if err_msg
x = send out_msg, stdout, out, "In stdout" if out_msg
(!stdout || x) && (!stderr || y)
end