Matt Leventhal has a WDL of root entity-type "pair set".
For each pair in the pair set. Matt wanted to refer to the files under a specific column. For the WDL input of datatype "Array[File]+" he put
in the method config "this.pairs.THE_COLUMN_NAME".
Upon running the WDL however, the input resolved to "[]" (an empty array).
Inspection of the data entity model showed that one of the pairs in the pair set had an empty value for that column.
After creating a pair-set without that pair, he re-ran the WDL and this time, the input resolved to an expected list of files. The number of pairs in the set is more than 50. And only one was missing a value in the column.
In the first case, would it be better, instead of evaluating to an empty array to a) have a message saying that one of the pairs is missing a file or b) simply "pick up" the files for the pairs that did have them and use those for inputs?