Repeatable Unit Tests require that the job under test produce deterministic data based on a set of predefined inputs and parameters. Calculations based on the current date are common in DataStage jobs but will cause the output produced by jobs to change depending on the date the job executed. This page outlines practices aimed at ensuring jobs using current date calculations are able to be validly tested.
Transformer Stages using CurrentDate(), CurrentTime() or CurrentTimestamp() functions
Unless your date calculation requires an exact date/time a record was being processed, the standard CurrentDate(), CurrentTime() and CurrentTimestamp() functions can be substituted with the DSJobStartDate, DSJobStartTime and DSJobStartTimestamp macros which can be set to a specific value during testing. Add DSJobStartDate, DSJobStartTime and/or DSJobStartTimestamp to the parameters clause of the Unit Test Specification and set the appropriate date and time values used during Unit Testing.
...
when:
parameters:
DSJobStartDate: 2012-01-15
DSJobStartTime: 11:05:01
Be careful when setting DSJobStartTimestamp in conjunction with either DSJobStartDate or DSJobStartTime, the MettleCI Unit Testing feature does not enforce that these parameters are logically consistent.
Ignoring columns which are known to be non-deterministic
Rather than ensuring that a job under test produces deterministic data, you may decide to exclude one or more output columns from Unit Test comparisons. This can be done by adding the columns to be ignored to the then clause of the Unit Test Specification.
given:
...
when:
...
then:
- stage: Transform
link: Output
path: Transform-Output.csv
ignore:
- CREATION_DATE
- LAST_UPDATED
Danger: Ignoring columns will prevent known, non-deterministic behavior from affecting test results but it is important to remember that ignoring columns is the same as not testing those columns.