Testing flow by using date/time references

To run repeatable tests in DataStage, the data flow must always produce the same results from the same inputs. However, using the current date or time in calculations can make the output vary depending on when the job runs. You can design jobs that use the current date in a way that still allows for reliable testing.

Transformer Stages that use system time and date functions

Transformer stages with derivations that use the CurrentDate(), CurrentTime() or CurrentTimestamp() functions need to be considered carefully when you design your tests. Unless your calculation requires a specific date and/or time, consider replacing the following functions: CurrentDate(), CurrentTime(), and CurrentTimestamp() with calls to the DSJobStartDate, DSJobStartTime and DSJobStartTimestamp macros.

Add DSJobStartDate, DSJobStartTime, and DSJobStartTimestamp (as required) to the parameters clause of the test Specification when node and set the appropriate date and time values that are used during Unit Testing.

See the example of two Transformer stage variables that use the following expressions:

BeforeToday =
If inPurchases.Purchase_Date < DSJobStartDate Then "Yes" else "No"

EarlierToday = 
If inPurchases.Purchase_Date = DSJobStartDate and 
   inPurchases.Purchase_Time < DSJobStartTime Then "Yes" else "No"

in this case, the when section of your test specification is:

{
    "given": [
        ...
    ],
    "when": {
        "data_intg_flow_ref": "example_flow_data_intg",  
        "parameters": {
            "DSJobStartDate": "2012-01-15",
            "DSJobStartTime": "11:05:01"
        }
    },
    "then": [
        ...
    ]
}

Note: Be careful when you use multiple date/time macros.

Exercise caution when setting `DSJobStartTimestamp` in conjunction with either `DSJobStartDate` or `DSJobStartTime` as the DataStage test case capability does not attempt to enforce logical consistency between these parameters. i.e. You could specify conflicting values for these macros which would create a contradictory logical condition. e.g.
```json
{
    "when": {
        "data_intg_flow_ref": "blah-blah-blah",  
        "parameters": {
            "DSJobStartTimestamp": "2025-02-03 00:00:00", 
            "DSJobStartDate": "2024-04-05"
            "DSJobStartTime": "09:30:00"
        }
    }
}
```