Forum Discussion

mfoster711's avatar
mfoster711
Regular Contributor
20 days ago

Check if running next test item

I have a Python Class that gets called from numerous places in our code. In that class, I have check to determine if this is the first time to call the class and it will perform some setup code if it...
rraghvani's avatar
rraghvani
Icon for Champion Level 3 rankChampion Level 3
19 days ago

In JavaScript, I've created a Singleton Class which gets instantiated once, and is called in every test. It reads a configuration file i.e. Storages.INI method, and sets up appropriate parameters, variables etc. While the scripts are running, only one instance is created, and if I create a new instance of the singleton class, the same object is returned.

The same can be applied in Python, see The Singleton Pattern as an example

mfoster711's avatar
mfoster711
Regular Contributor
19 days ago

I do something similar in Python. The problem is, Python retains the singleton between test items. If I run 10 test items, the singleton only gets created once. This is normally how I want python to work. 

But, I have a specific case where I need to reset some values but only when running a new test item. 

  • Hassan_Ballan's avatar
    Hassan_Ballan
    Icon for Champion Level 3 rankChampion Level 3
    19 days ago

    You could use TestComplete Variables, but that just tracks state — it doesn’t solve the real issue, which is that Python persists for the entire run in TestComplete.

    A cleaner approach is to reset your singleton at the start of each Test Item using a project event.

    Do this:

    1. Go to Project → Events
    2. Add an OnStartTest handler
    3. Reset your class there

    Example:

    def GeneralEvents_OnStartTest(Sender):
    MySingleton.reset()

    And in your class:

    class MySingleton:
    _instance = None

    @classmethod
    def reset(cls):
        cls._instance = None

    Since OnStartTest fires for every Test Item, this guarantees your setup runs once per Test Item without changing how the class is used elsewhere.

    🤖 AI-assisted response
    👍 Found it helpful? Click Like
    ✅ Issue resolved? Click Mark as Solution

    • mfoster711's avatar
      mfoster711
      Regular Contributor
      19 days ago

      This works. I was thinking there would be a more Python specific solution but this is really a TestComplete issue and TestComplete solution.

      • rraghvani's avatar
        rraghvani
        Icon for Champion Level 3 rankChampion Level 3
        16 days ago

        I wouldn't recommend setting the singleton instance to None just to reset its variables. That effectively breaks the singleton guarantee and alters its lifecycle semantics.

        If the goal is to clear state (for example, between tests), it's cleaner to provide a method on the singleton that resets its internal variables. This keeps the instance intact while preserving the intent of the pattern.

        You can then call the method during either OnStartTest / OnStopTest or OnStartTestCase / OnStopTestCase event to reset the variables.