Do not set --prerunmodifier on each pabot thread

Extensions Pabot
1

I’m using a prebuild modifier to create multiple copies of a test case and passing some data to them, my issue is that pabot is calling --prerunmodifier for each run. Is there any way i can create the test cases but make pabot to not add the --prerunmodifier flag? As an example this is the code pabot execute for each test case:

robot --test ‘Regresivo.TC004 Generar links_codigo_6’ --variable openBrowser:False --variable CALLER_ID:7146a479c84e4b68b109e5e4e1f636c6 --variable PABOTLIBURI:127.0.0.1:8270 --variable PABOTEXECUTIONPOOLID:6 --variable PABOTISLASTEXECUTIONINPOOL:0 --variable PABOTNUMBEROFPROCESSES:10 --variable PABOTQUEUEINDEX:6 --variable ‘PABOTLASTLEVEL:Regresivo.TC004 Generar links_codigo_6’ --outputdir /tmp/pabot_results/6 --listener RobotStackTracer –prerunmodifier /tmp/PreRunModifier.py --log NONE --report NONE --xunit NONE --consolecolors off --consolemarkers off /tmp/claro/TestCases/Regresivo.robot

I’m open to other solutions, datadriven does not work for me because the amount of test cases I need to add dinamically depend on a dinamically generated list.

2

Hi Wilson,

If everything is running on the same machine a simple “lock file” approach could be used, the first instance of PreRunModifier.py creates the lock file and the others on detecting it exit as it’s already been run, you could also add a step to your suite teardown to remove the lock file if you want.

Another approach would be to put the PreRunModifier.py content into a keyword you call from RF, add it to your suite startup with pabot’s keyword Run Setup Only Once

These are the simplest suggestions I have, but if your environment is more complex you might need another approach.

Hope that helps,

Dave.

3

Thank you for your reply, this is what I have so far in my prerunmodifier:

def visit_test(self, data):
    parser = ParseVariablesLibrary()
    values = parser.parse_data("file", "name")
    test_cases = []
    if "TC004" in data.tags:
        for brand in values:
        #print(f"Test case nuevo agregado: {testcase.body}")
            new_test = data.copy(name=f"{data.name}_{marca['marca']}")
            new_test.body.insert(0, new_test.body.create_keyword(name="Set Test Variable", args=["@{variable}",brand]))
            self.suite_test_cases.append(new_test)
    else:
        self.suite_test_cases.append(data)
    self.visited = True

The idea is that if the test case has a TC004 tag, it will create copies of the same test case with a variable named “${variable}” for each “brand”, and it does it perfect if running with robot.

My issue is that when I run it with pabot, the prerunmodifier is being called on each new thread and if I have 10 items inside values, the dinamic generated test cases are going to have 10 times the variable “${variable}”.

4

Hi Wilson,

I have no experience with using prerunmodifiers, so I have no idea how pabot will handle the test cases, so you’ll have to try it and see.

As I mentioned you can create a lock file to stop the prerunmodifier appending the TC004 tests multiple times, it would look something like this (I’ll make some minor modification to your code):

import os

def visit_test(self, data):
    parser = ParseVariablesLibrary()
    values = parser.parse_data("Datos", "Crear Equipos")
    test_cases = []
    if "TC004" in data.tags:
        if not os.path.exists("TC004.lock"):
            with open(path, "w+") as f:
                f.write("TC004") 
            for brand in values:
                #print(f"Test case nuevo agregado: {testcase.body}")
                new_test = data.copy(name=f"{data.name}_{marca['marca']}")
                new_test.body.insert(0, new_test.body.create_keyword(name="Set Test Variable", args=["@{variable}",brand]))
                self.suite_test_cases.append(new_test)
    else:
        self.suite_test_cases.append(data)
    self.visited = True

So this will run as it does now, but will check for the file TC004.lock if it’s found it does nothing, if it’s not found it creates it first and then creates the test cases as before

see if that works for you,

Dave.

5

I’m open to changing pre-run modifiers so that they would be ran only once in pabot main process.
This would be a backward incompatible change and have to say that I have no way of understanding the potential negative impacts.

6

Hi Mikko,

Some ideas rather than having a breaking change:

  • A shared variable area that the pre-run modifiers can access to set / read a variable, then people can manage the “run once” control themselves with a if statement.
  • A function that does something similar to Run Setup Only Once.
  • A run_once decorator for functions like visit_test

I’ll leave it to you to decide what’s best for pabot

Dave.

7

I solved my issue, the issue was the following code:

new_test = data.copy(name=f"{data.name}_{marca['marca']}")

It seems that instead of creating a copy of the testcase, it was creating a copy with a different name but referencing the original test case, so every time I called the following:

new_test.body.insert(0, new_test.body.create_keyword(name="Set Test Variable", args=["@{variable}",brand]))

The original test case with tag TC004 also received the insertion of the keyword, so If I created 10 copies, the Set Test Variable was inserted 10 times in the original TC also. I imported the copy library and use the deepcopy funcion. That was the trick.

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