- add helper try_user_config_location()
    - search for new config location to be set inside R/app_config.R
- update guess_where_config() with a final guess using this helper
- run styler::style_file("R/config.R", transformers =
  grkstyle::grk_style_transformers())

- path changes mean new dir and new filename so:
  - create a new dir for config
  - move config to that dir and rename

=> test correctly identifies changes (changing dir AND changing filename) in the yaml-config.

attribute to @ALanguillaume with some minor tweaks

Co-authored-by: ALanguillaume <[email protected]>

…n()`

- encapsulate finding the relevant lines in the config file into "guess_lines_to_config_file()"
    - function allows for multi-line/grk-style app_sys()-calls (if file path to long and must be put into next line)
    - has clearer and commented logic to find the lines
- document proper logic of function with comments
- style with `grkstyle::grk_style_transformer`
- update `tests/testthat/test-config.R` to incorporate above changes and move code coverage of that file to 63.16%

- allows valid comparison with fs_path()'s inside guess_where_config() and output values from try_user_config_location()
- fix a typo in a comment

Why:

- clearly outline the different cases: since now the user can add a golem-config, there can be conflicting cases between the default golem config and the user golem config (if e.g. the user forgets to delete the default)
- update the tests to check these different cases
- remark: test inside testthat should work without golem:: prefixes

- test that config file can be found if
   - we end up inside "inst/" (a corner case not tested before)
   - guess_where_config() is fed with argument values for 'path' and 'file' that do not work

-> improves code coverage to 70.75%

- remove last if-statement (which is almost a duplicate of the one before)
   -> this makes the guess_where_config() fail easier (i.e. return NULL) as other exotic corner cases should be handled more explicitly
- remark: golem::pkg_path() will (almost) never produce an error but this may change so the try-construct within attempt() is kept

- improve comments for corner case IV.B as internal developer note

- notably: add package mockery to Suggests (no dependencies except for testthat and used for tests only)

- add tests for non-interactive usage of guess_where_config(): check that error is thrown correctly

- add tests for interactive usage of guess_where_config():
    - user says yes: test that necessary files are created
    - user says no: test that we return NULL

- add tests for encapsulated ask_golem_creation_upon_config()
    - shallow test as non-interactive menu() calls (inside the yesno()) are forbidden
    - but this makes code coverage 100% :)

- only exported function from R/config.R needs proper docs
- besides more details on older usage and behavior:
    - add docs on how to set user supplied golem config
    - add code snippets