Whenever I drop a debugging breakpoint with byebug, I am noticing inconsistencies with the text that I type. For instance, I am able to type the first 2-3 characters. However, after the first 2-3 characters, the terminal starts adding random square brackets and other characters. For instance when I type env, Byebug outputs: eenv, or when I try to access a key in env Byebug outputs something even worse: ^[[Aenv['QUERY_STRING'']^[[.
Has anyone ran into this problem with Byebug?
A similar issue occurred to me while working in ruby on rails, using multiple workers. I am making the assumption here that OP is using rails because env and query strings are mentioned in the output.
So, if you are running multiple workers while debugging, they can cause this sort of behaviour, because code is still being executed after the byebug breakpoint is hit, and more importantly: while you try to type letters in the terminal, causing input to get jumbled. Debugging middleware can exacerbate this behaviour, since middleware is always hit, causing this issue to happen only while debugging certain components but not for an example controllers.
Ensure that only one worker is hitting your breakpoint at a time. This could be done by setting your development environment to never run more than 1 worker at least for the time being
This is a parallelization issue. Either with multiple workers while running rails server, OR in my case it was:
class ActiveSupport::TestCase
# Run tests in parallel with specified workers
parallelize(workers: :number_of_processors) # <--- this is a madness freaking root
end
byebug (and any bb-based gem) terminal input going nuts after hitting a break point in this case
Related
If I'm at a Bash prompt and I type bash I can then detect that I'm at the 2nd level by typing echo $SHLVL.
Suppose I'm in a pry session and I type pry again. How can I detect that I'm at the 2nd level down? How can I detect the Pry level? Nothing listed in (Pry.methods - Object.methods).sort seems to have anything useful.
This is for testing some code for a pry-related project, where I need detect the level.
If you call caller within a pry session within a pry session, then you will see a list of commands. Among them, you should be able to find the part that corresponds to a nested pry call. Find the crucial line that is related to each pry session call, and you will know your level. As far as I checked, you should find two occurrences of a line like:
"/usr/local/lib/ruby/gems/2.2.0/gems/pry-0.10.1/lib/pry/repl.rb:67:in `repl'"
Count such lines.
I have a ruby script, apparently correct, that sometimes stops working (probably on some calls to Postgresql through the pg gem). The problem is that it freezes but doesn't produce any error, so I can't see the line number and I always have to isolate the line by using puts "ok1", puts "ok2", etc. and see where the script stops.
Is there any better way to see the current line being executed (without changing the script)? And maybe the current stack?
You could investigate ruby-debug a project that has been rewritten several times for several different versions of ruby, should allow you to step through your code line by line. I personally prefer printf debugging in a lot of cases though. Also, if I had to take an absolutely random guess at your problem, I might investigate whether or not you're running into a race condition and/or deadlock in your DB.
I like Mocha so far but I'm not fond of this when I'm doing continous testing:
watching
watching
watching
watching
watching
watching
[repeat many times]
If I haven't run a test for a while and I want to see the output of the last test it's scroll scroll scroll. It quickly swamps my console buffer. Can I change this behavior without changing mocha's source code?
EDIT: this has been fixed and pulled into master.
Per https://github.com/visionmedia/mocha/blob/master/bin/_mocha#L287-303,
the mocha command gives the test runner a callback that prints a series of strings to the console, and there aren't any cmd line flags that would affect that behavior.
The root of the problem seems that the animation's control characters might be failing in your terminal, though, as it's supposed to do a pretty-looking spinning symbol at the beginning, and then do a character return (not line feed) to rewrite the line after every printout.
If you're really dead-set on changing that behavior without modifying mocha's source, you could make a copy the bin/_mocha file, and just replace the play() function with one that suits your needs. Make sure to fix up all the relative paths.
So let's say pretty often a script runs that opens a browser and does web things:
require 'watir-webdriver'
$browser = Watir::Browser.new(:firefox, :profile => "botmode")
=> #<Watir::Browser:0x7fc97b06f558 url="about:blank" title="about:blank">
It could end gracefully with a browser.close, or it could crash sooner and leave behind the memory-hungry Firefox process, unnoticed until they accumulate and slow the server to a crawl.
My question is twofold:
What is a good practice to ensure that even in case of script failure anywhere leading to immediate error exit, the subprocess will always get cleaned up (I already have lots of short begin-rescue-end blocks peppered for other unrelated small tests)
More importantly, can I simply remember this Watir::Browser:0x7fc97b06f558 object address or PID somehow and re-assign it to another $browser variable in a whole new Ruby process, for example irb? I.e. can an orphaned browser on webdriver be re-attached later in another program using watir-webdriver on the same machine? From irb I could then get in and re-attach to the browser left behind by the crashed Ruby script, to examine the website it was on, check what went wrong, what elements are different than expected, etc.
Another hugely advantageous use of the latter would be to avoid the overhead of potentially hundreds of browser startups and shutdowns per day...best to keep one alive as sort of a daemon. The first run would attempt to reuse a previous browser object using my specially prepared botmode profile, otherwise create one. Then I would deliberately not call $browser.close at the end of my script. If nothing else I run an at job to kill the Xvfb :99 display FF runs inside of at the end of the day anyway (giving FF no choice but to die with it, if still running). Yes I am aware of Selenium standalone jar, but trying to avoid that java service footprint too.
Apologies if this is more a basic Ruby question. I just wasn't sure how to phrase it and keep getting irrelevant search results.
I guess, U cant just remember the variable from another process. But the solution might be creating a master process and process your script in loop in thread, periodically checking the browser running state. I'm using some thing similar in my acceptance tests on Cucumber + watir. So it will be some thing like that:
require 'rubygems'
require 'firewatir' # or watir
#browser = FireWatir::Firefox.new
t = Thread.new do
#browser.goto "http://google.com"
#call more browser actions here
end
while not_exit?
if t.stop?
# error occurred in thread, restart or exit
end
if browser_live?
# browser was killed for a some reason
# restart or exit
end
end
#browser.close
not_exit? - can be over TRAP for the ctrl+C
browser_live? - you can check if firefox browser running with processes listings
It is quite tricky but might work for you
You can use DRb like this:
browsers pool:
require 'drb'
require 'watir'
browser = Watir::Browser.new :chrome
DRb.start_service 'druby://127.0.0.1:9395', browser
gets
and then from test script use this browser:
require 'drb'
browser = DRbObject.new_with_uri 'druby://127.0.0.1:9395'
browser.goto 'stackoverflow.com'
I'm pretty sure that at the point ruby exits, any handles or pointers to something like a browser object would become invalid. So re-using something in a later ruby process is likely not a good approach. In addition I might be wrong on this, but it does seem that webdriver is not very good at connecting to a running browser process. So for your approach to work it would really all need to be wrapped by some master process that was calling all the tests etc.. and hey wait a sec, that's starting to sound like a framework, which you might already (or perhaps should be) using in the first place.
So a better solution is probably to look at whatever framework you are using to run your tests and investigate any capability for 'setup/teardown' actions (which can go by different names) which are run before and after either each test, groups of tests, or all tests. Going this way is good since most frameworks are designed to allow you to run any single test, or set of tests that you want to. And if your tests are well designed they can be run singly without having to expect the system was left in some perfect state by a prior test. Thus these sorts of setup/teardown actions are designed to work that way as well.
As an example Cucumber has this at the feature level, with the idea of a 'background' which is basically intended as a way to dry out scenarios by defining common steps to run before each scenario in a feature file. (such as navigating to and logging into your site) This could include a call to a series of steps that would look to see if a browser object existed, and if not create one. However you'd need to put that in every feature file which starts to become rather non dry.
Fortunately cucumber also allows a way to do this in one place via the use of Hooks. You can define hooks to run before steps, in the event of specific conditions, 'before' and 'after' each scenario, as well as code that runs once before any scenarios, and code defined to run 'at_exit' where you could close the browser after all scenarios have run.
If I was using cucumber I'd look at the idea of a some code in env.rb that would run at the start to create a browser, complemented by at_exit code to close the browser. Then perhaps also code in a before hook which could check to see that the browser is still there and re-create it if needed, and maybe logout actions in a after hook. Leave stuff like logging in for the individual scenarios, or a background block if all scenarios in a feature login with the same sort of user.
Not so much a solution but a workaround for part 1 of my question, using pkill. Posting here since it turned out to be a lot less trivial than I had hoped.
After the ruby script exits, its spawned processes (which may not at all belong in the same PID tree anymore, like firefox-bin) have a predictable "session leader" which turned out to be the parent of the bash shell calling rubyprogram.rb in my case. Available as $PPID in Bash, for when you have to go higher than $$.
Thus to really clean up unwanted heavyweight processes eg. after a ruby crash:
#!/bin/bash
# This is the script that wraps on top of Ruby scripts
./ruby_program_using_watirwebdriver_browser.rb myparams & # spawn ruby in background but keep going below:
sleep 11 # give Ruby a chance to launch its web browser
pstree -panu $$ # prints out a process tree starting under Bash, the parent of Ruby. Firefox may not show!
wait # now wait for Ruby to exit or crash
pkill -s $PPID firefox-bin # should only kill firefox-bin's caused above, not elsewhere on the system
# Another way without pkill, will also print out what's getting killed if anything:
awk '$7=="firefox-bin" && $3=="'$PPID'" {print $1}' <(ps x -o pid,pgid,sess,ppid,tty,time,comm) | xargs -rt kill
OPTIONAL
And since I use a dedicated Xvfb Xwindows server just for webdriving on DISPLAY :99, I can also count on xkill:
timeout 1s xwininfo -display :99 -root -all |awk '/("Navigator" "Firefox")/ {print $1}' |xargs -rt xkill -display :99 -id
# the timeout is in case xkill decides to wait for user action, when window id was missing
Just an update on part 2 of my question.
It seems one CAN serialize a Watir:Browser object with YAML, and because it's text-based the contents were quite interesting to me (e.g. some things I've only dreamed of tweaking hidden inside private elements of private classes...but that's a separate topic)
Deserializing from YAML is still trouble. While I haven't tested beyond the first try it gives me some kind of reg exp parse error...not sure what that's about.
(more on that at at how to serialize an object using TCPServer inside? )
Meanwhile, even attempting to serialize with Marshal, which is also built-in to Ruby but stores in binary format, results in a very reasonable-sounding error about not being able to dump a TCPServer object (apparently contained within my Watir:Browser pointed to by $browser)
All in all I'm not surprised at these results, but still pretty confident there is a way, until Watir arrives at something more native (like PersistentWebdriver or how it used to be in the days of jssh when you could simply attach to an already running browser with the right extension)
Until then, if serialization + deserialization to a working object gets too thorny I'll resort to daemonizing a portion of my Ruby to keep objects persistent and spare the frequent and costly setup/teardowns. And I did take a gander at some established (unit testing) frameworks but none seem to fit well yet within my overall software structure--I'm not web testing after all.
Too often people write tests that don't clean up after themselves when they mess with state. Often this doesn't matter since objects tend to be torn down and recreated for most tests, but there are some unfortunate cases where there's global state on objects that persist for the entire test run, and when you run tests, that depend on and modify that global state, in a certain order, they fail.
These tests and possibly implementations obviously need to be fixed, but it's a pain to try to figure out what's causing the failure when the tests that affect each other may not be the only things in the full test suite. It's especially difficult when it's not initially clear that the failures are order dependent, and may fail intermittently or on one machine but not another. For example:
rspec test1_spec.rb test2_spec.rb # failures in test2
rspec test2_spec.rb test1_spec.rb # no failures
In RSpec 1 there were some options (--reverse, --loadby) for ordering test runs, but those have disappeared in RSpec 2 and were only minimally helpful in debugging these issues anyway.
I'm not sure of the ordering that either RSpec 1 or RSpec 2 use by default, but one custom designed test suite I used in the past randomly ordered the tests on every run so that these failures came to light more quickly. In the test output the seed that was used to determine ordering was printed with the results so that it was easy to reproduce the failures even if you had to do some work to narrow down the individual tests in the suite that were causing them. There were then options that allowed you to start and stop at any given test file in the order, which allowed you to easily do a binary search to find the problem tests.
I have not found any such utilities in RSpec, so I'm asking here: What are some good ways people have found to debug these types of order dependent test failures?
There is now a --bisect flag that will find the minimum set of tests to run to reproduce the failure. Try:
$ rspec --bisect=verbose
It might also be useful to use the --fail-fast flag with it.
I wouldn't say I have a good answer, and I'd love to here some better solutions than mine. That said...
The only real technique I have for debugging these issues is adding a global (via spec_helper) hook for printing some aspect of database state (my usual culprit) before and after each test (conditioned to check if I care or not). A recent example was adding something like this to my spec_helper.rb.
Spec::Runner.configure do |config|
config.before(:each) do
$label_count = Label.count
end
config.after(:each) do
label_diff = Label.count - $label_count
$label_count = Label.count
puts "#{self.class.description} #{description} altered label count by #{label_diff}" if label_diff != 0
end
end
We have a single test in our Continuous Integration setup that globs the spec/ directory of a Rails app and runs each of them against each other.
Takes a lot of time but we found 5 or 6 dependencies that way.
Here is some quick dirty script I wrote to debug order-dependent failure - https://gist.github.com/biomancer/ddf59bd841dbf0c448f7
It consists of 2 parts.
First one is intended to run rspec suit multiple times with different seed and dump results to rspec_[ok|fail]_[seed].txt files in current directory to gather stats.
The second part is iterating through all these files, extracts test group names and analyzes their position to the affected test to make assumptions about dependencies and forms some 'risk' groups - safe, unsafe, etc. The script output explains other details and group meanings.
This script will work correctly only for simple dependencies and only if the affected test is failing for some seeds and passes for another ones, but I think it's still better than nothing.
In my case it was complex dependency when effect could be cancelled by another test but this script helped me to get directions after running its analyze part multiple times on different sets of dumps, specifically only on the failed ones (I just moved 'ok' dumps out of current directory).
Found my own question 4 years later, and now rspec has a --order flag that lets you set random order, and if you get order dependent failures reproduce the order with --seed 123 where the seed is printed out on every spec run.
https://www.relishapp.com/rspec/rspec-core/v/2-13/docs/command-line/order-new-in-rspec-core-2-8
Its most likely some state persisting between tests so make sure your database and any other data stores (include class var's and globals) are reset after every test. The database_cleaner gem might help.
Rspec Search and Destroy
is meant to help with this problem.
https://github.com/shepmaster/rspec-search-and-destroy