As part of building an automation framework, typically you’re facing the challenge to separate the data from logic as this is the key to an agile and re-usable solution. The automation logic by itself should “only” know how to process data within a workflow, but the logic by itself shouldn’t know any (hard-coded) value. Instead, the logic should get data values from separate resources like configuration files, registry, databases, whatever. With separation of data and logic it’s almost a no-brainer to set up the solution for another environment, not to mention maintenance that is as easy as pushing DEV into the git repo and pulling the changes into TEST and PROD for example. I personally like to maintain data in hashtables, to be more precise I usually have for example config-global.ps1 and a config-abbreviation.ps1 file per environment that 1. adds specific environment settings and 2. overrides baseline settings from the global config. These ps1 files only contain a (usually nested) hash table. In order to import the data I dot-source both the global config and the environment config. The next step is the creation of a single data resource from both hash tables; meaning that I’m able to access the keys and their values through a single variable like $ConfigData afterwards.
Merging hash tables is straightforward as long as each hash table contains different keys: it’s simply $hashTable1 + $hashTable2. In case of duplicate keys this approach will fail because PowerShell isn’t able to resolve that conflict by deciding which key takes precedence. That’s why I wrote the function Merge-Hashtables (get your copy from the TechNet Gallery). Merge-Hashtable creates a single hash table from two given hash tables. The function considers the first hash table as baseline and its key values are allowed to be overridden by the second hash table. Internally, Merge-Hashtables uses two sub functions. The first sub function detects duplicates and adds for each conflict the key of the second hash table to the resulting hash table. The second sub function adds additional keys from the second hash table to the resulting hash table. Both sub functions are designed to support nested hash tables through recursive calls.
Hope this helps.