The problem is in relation to the radis-rb gem.
The exception is not caught by my rescue block and my app goes down.
My code:
begin
redis = Redis.new
puts "WTF?"
rescue Exception
puts "Exception"
end
If redis is down, the message WTF? is exposed.
It happens with or without the Exception statement.
Why is the exception not raised to my rescue block?
I have solved the problem myself (with help from the community and comments).
The exception occurred in IRB only.
The reason of one is IRB's inspect call when IRB try to print result of Redis.new.
In the script (not IRB), the exception doesn't occur because Redis.new does not raise an exception if the Redis service is down.
This question helped to solve my problem.
Related
In a Ruby on Rails app, I rescue an exception in a known scenario. In the rescue, my code does a little clean up then moves on without re-raising the exception.
I want to log details of the exception to SignalFx. I believe this happens automatically if the exception is not rescued. But in this case I need to rescue it.
We are currently migrating from New Relic to SignalFx. In New Relic, I could force the rescued exception to be logged like this:
rescue MySpecialError => ex
NewRelic::Agent.notice_error ex
record.clean_up_after_my_special_error()
This would record the stack trace, request params, env vars, etc, exactly as if the exception was not rescued.
Is there a similar way with SignalFx to capture rich exception information without raising the exception?
According to the docs,
client = SignalFx.new 'MY_SIGNALFX_TOKEN'
client.send_event('EXCEPTION', ... )
You may want to consider using a more focused error-reporting service.
Recently, I am working on mobile automation using appium+selenium in ruby. But stopped by the following issue: selenium driver is quit automatically (mobile app is closed) every time an exception happens. This will result in that the following code to access the driver will fail after I manage to rescue the exception.
e.g.
begin
#driver.find_element(:xpath, "//window[1]/button[27]")
rescue
#driver.find_element(:xpath, "//window[1]/navigationBar[1]/button[2]").click
end
Does anyone have this issue as well?
According to http://www.ruby-doc.org/core-2.1.1/doc/syntax/exceptions_rdoc.html "By default StandardError and its subclasses are rescued. You can rescue a specific set of exception classes (and their subclasses) by listing them after rescue:
begin
# ...
rescue ArgumentError, NameError
# handle ArgumentError or NameError
end
I assume you are waiting for something like ElementNotVisibleException. So, add type of exception after rescue. Something like rescue ElementNotVisibleException.
Im trying to get the backtrace in sinatra in case of an error.
I know rails has one in
Rails.respond_to?(:backtrace_cleaner)
and I saw that sinatra is suppose to have one (by default enabled) in STDERR
So i tried
STDERR.inspect
and I got #<IO:<STDERR>>
When rescuing the exception, catch the exception object.
begin
raise "hello"
rescue => e
e.backtrace
end
In Ruby you can call a method caller at any place and get a full backtrace as an array.
I use rufus scheduler to run overnight test scripts by calling my functions.
Sometimes I can see "scheduler caught exception:" a message that threw some of my functions. Then scheduler stops execution of following test cases.
How can I make it so scheduler runs all test cases regardless of any exception caught?
This is called "exception swallowing". You intercept an exception and don't do anything with it.
begin
# do some dangerous stuff, like running test scripts
rescue => ex
# do nothing here, except for logging, maybe
end
If you do not need to do anything with the exception, you can omit the => ex:
begin
# do some dangerous stuff, like running test scripts
rescue; end
If you need to rescue Exceptions that don't subclass from StandardError, you need to be more explicit:
begin
# do some dangerous stuff, like running test scripts
rescue Exception
# catches EVERY exception
end
I will sometimes use the fact that you can pass blocks to a method, and I have the method rescue errors, and my code can continue on its way.
def check_block
yield
rescue NoMethodError => e
<<-EOR
Error raised with message "#{e}".
Backtrace would be #{e.backtrace.join('')}
EOR
end
puts check_block {"some string".sort.inspect}
puts check_block {['some', 'array'].sort.inspect}
This first block will go through and rescue with a report returned, the second will operate normally.
This rescue only rescues NoMethodError while you may need to rescue other errors.
I have a set of cucumber tests that get run on a build server.
I often want faster feedback than the server directly provides and so I watch the console output as it runs. I was wanting a way of identifying any failing test with a single search term so I modified our Around to print "Failed Test" on any exception, but Ruby doesn't seem to be handing the exception back up to the around. I've verified this by having puts statements after the begin ... end.
Does anyone know why this is happening or a way of wrapping any exception thrown from a failing test in a begin?
Around() do |scenario, block|
begin
Timeout.timeout(0.1) do
block.call
end
rescue Timeout::Error => e
puts "Failed Test"
puts caller
rescue Exception => e
puts "Failed Test"
raise e
end
end
Looking at cucumber 1.3.12 it actually rescues any exceptions from scenario steps. So you can't see them in any way without modifying cucumber gem.
See my answer on how to put a debug hook in that place for more information:
https://stackoverflow.com/a/22654786/520567
Have you tried disabling Cucumber's exception capturing with the #allow-rescue tag?
#allow-rescue: Turns off Cucumber’s exception capturing for the tagged scenario(s). Used when the code being tested is expected to raise and handle exceptions.
https://github.com/cucumber/cucumber/wiki/Tags