Add a function for preprocessing an output before taking a test snapshot — snapshotPreprocessOutput
  v1.8.0|Source: 
  
  
    
R/snapshot.R
  Description
Add a function for preprocessing an output before taking a test snapshot
Arguments
- x
- A reactive which will be assigned to an output. 
- fun
- A function that takes the output value as an input and returns a modified value. The returned value will be used for the test snapshot.