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.
Related
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
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.
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.
Sometimes things are missing from my irb history. This has been happening for years and I haven't really noticed a pattern. I'll use irb for a while, control-d out of it, come back in a few minutes later, and the commands I was just using aren't there, but commands from earlier in the day or week are there. This is mostly/always in a rails console.
Here's my .irbrc
I could be wrong, but reading over http://trac.greenstone.org/browser/extensions/gsdl-video/trunk/installed/cmdline/lib/ruby/1.8/irb/ext/save-history.rb?rev=18425
makes me think that the last irb process will overwrite the other processes history with its own.
So if you run:
irb
irb #in another term window
"a string" #then Ctrl-D in the first
#Ctrl-D in the second
then your .irb-history should be unchanged, as the initial, backgrounded irb will have loaded the old history, then overwritten the new history as it exits.
ie: Somewhat foolishly: open('w') rather than open('a') is the culprit.
You might consider writing a patch and commiting it for the greater good if this strongly irritates you.
I'm developing a ruby app with Vim in one screen, and in another I'm using irb to test the code I'm writing in Vim.
For the sake of this example, we'll say there are only 2 irb commands to test the code that I've written, a load and a method call.
Generally, it's more than 2 commands - if its just 2 I would tap the up arrow twice and hit enter, but generally its around 5 or 6 and that's up to 36 key presses just to run the last 6 commands. There must be an easier way.
Is there an easy way to execute the last X commands from the irb readline history buffer in the order they were executed, where X is the number of commands you want to run? Something like;
run_last_x_commands(i)
I'm pretty sure it would be a custom written piece of code, I'm just wondering if anyone already solved this problem or if this is something I'll need to write myself.
You may be interested in running Vim in IRB.
Gem.
Source.
I would really store your test script in a file. It is less convenient than just typing it out, but at the same time, it's easier to edit and work with. Plus, if you're trying to define classes, you often get issues with IRB not able to redefine a class without doing things like Object.remove_const('MyClass'). I've had the same problem you're having, and I decided against using IRB for this task.
There may be some readline magic to do what you want though. Readline has all kinds of tricks and shortcuts I don't know about.