Prevent duplicating stderr/stdout for run_simple commands

[e2]

Summary

When stderr+stdout announcing is enabled for run_simple in RSpec, both announcements are duplicated.

E.g. if a cli command outputs "hello world" in STDOUT, you'll see:

<<-STDOUT
hello world
STDOUT

<<-STDOUT
hello world
STDOUT

Expected Behavior

If the command is only run once, it should print each stderr/stdout announcement only once.

Current Behavior

Currently, the stop() call in run_simple() sends the notifications to announce the process's stderr+stdout. Then, stop_all_commands does the same.

Possible Solution

The sanest "workaround" for now is: just temporarily disable announcing during the stop in run_simple. Since the output is gathered when the process ends anyway, this isn't a problem.

I implemented this in my own fork here:

e2@c540485

Ideally, there should be a way to "consume" stderr/stdout during announcements. And ideally there would be a "streaming" of stderr/stdout live while the app is running.

Steps to Reproduce (for bugs)

1. Aruba + RSpec
2. Activate announcing for stdout
3. run_simple with a simple 'hello world' script
4. You'll have the announcement appear twice (once for stop inside run_simple, and once for stop_all_commands when the test is done)

Context

I want to see the output of commands - and it's annoying to get errors showing up multiple times on the screen. Especially annoying is having two sets of stdout+stderr. No to mention it's very confusing. (At first I though somehow the test ran twice).

Your Environment

Project without cucumber (RSpec only, standard setup with aruba init --test-framework=rspec).

[maxmeyer]

I see. Good that you find the reason. Let me think about that one. Maybe we should an option to silently stop a command. WDYT?

[e2]

No, I don't think that would be useful. Users don't know that the output is announced during stop. It's too low level to know about it.

Just think of Ruby's backticks syntax to execute and capture output - it's simple and understandable with no options. There's no "double output" or silencing option. The same with popen and open3 - the fact that commands are stopped and streams are closed are almost invisible to the user.

What should happen instead is: Aruba should provide aggregated and partial output at all times. E.g. "announce-aggregated-stdout" would be the equivalent of what it does not. For short-running "run_simple" commands, you only want the aggregate anyway. (at least until Aruba supports live/real-time output in the future output).

E.g. The docker-api gem allows capturing and streaming out live output.

So this is a decent fix until then.

[jrab89]

I've noticed this too. For example, when running echo.feature:

Feature: echo

  @announce-stdout
  Scenario: With 'something' as input
    When I successfully run `echo something`
    Then the output should contain "something"

I get this:

$ cucumber features/echo.feature
Feature: echo

<<-STDOUT
something

STDOUT

<<-STDOUT
something

STDOUT

<<-STDOUT
something

STDOUT

  @announce-stdout
  Scenario: With 'something' as input          # features/echo.feature:4
    When I successfully run `echo something`   # aruba-0.14.1/lib/aruba/cucumber/command.rb:27
<<-STDOUT
something

STDOUT

    Then the output should contain "something" # aruba-0.14.1/lib/aruba/cucumber/command.rb:159
<<-STDOUT
something

STDOUT

<<-STDOUT
something

STDOUT


1 scenario (1 passed)
2 steps (2 passed)
0m0.121s

aruba 0.14.1
cucumber 2.4.0
rspec 3.5.2

[ghost]

Hi @jrab89 can you try to use the branch still and see if it's fixed by fff944b. I backported a fix from master. If your answer is yes, I'm going to release 0.14.3 with this fix.

[jrab89]

Using aruba from the still branch I'm getting

$ cucumber features/echo.feature                                                                                                                                                     
Feature: echo

<<-STDOUT
something

STDOUT

<<-STDOUT
something

STDOUT

<<-STDOUT
something

STDOUT

  @announce-stdout
  Scenario: With 'something' as input          # features/echo.feature:4
    When I successfully run `echo something`   # aruba-0.14.2/lib/aruba/cucumber/command.rb:27
<<-STDOUT
something

STDOUT

    Then the output should contain "something" # aruba-0.14.2/lib/aruba/cucumber/command.rb:159

1 scenario (1 passed)
2 steps (2 passed)
0m0.119s

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in a week if no further activity occurs.

[stale]

This issue has been automatically closed because of inactivity. You can support the Cucumber core team on opencollective.

[mvz]

This was fixed in the stale branch, but is potentially still a problem in master.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in a week if no further activity occurs.

[mvz]

Waiting for #517...