Add sepuku feature to switch from a fusen package to a "classic" package

[ymansiaux]

• Si pas de dossier dev/ : un message et on s'arrête

• Si pas de config_fusen.yml : avertir qu'on va lister les fichiers flat présent dans dev et flat_history

• Si fichier de config_fusen.yml : avertir qu'on va lister les fichiers flat présent dans dev et flat_history et dans ce fichier

Une fonction list_all_flat_files()

• Identification des fichiers dans R/

• Identification des fichiers dans tests/

• Identification des fichiers dans vignettes/

Une fonction find_files_generated_by_fusen()

To deal with :

• Ensure we are on a package

• Ensure we have a dev/ folder

• Absence of flat files in dev/ or dev/flat_history/

• Absence of dev/config_fusen.yml

  • We suppose that no flat file have been inflated yet : deleting all files starting with "flat*" in dev

• Thereafter we can work with dev/config_fusen.yml : it allows us to delete file not starting with "flat_"

  • Verify if all flat file starting with "flat_" are listed in this file

• Clean R/, vignettes/ and tests/ folders

• Look for messages starting with "# WARNING - Generated by {fusen}" in R/, vignettes/, tests/testthat folders

• Look for messages starting with "# Previously generated by {fusen} from" in R/, vignettes/, tests/testthat folders

• Delete dev/config_fusen.yml

• List files that we are about to delete and ask user for confirmation

• List all deleted files and folders

• Update NEWS

[ymansiaux]

We must call:

• list_flat_files()
• find_files_with_fusen_tags()

Warn the user about the file that will be deleted
Warn the user about the file that will be edited

• remove files found by list_flat_files()
• remove dev/flat_history()
• clean_fusen_tags_in_files()
• delete dev/config_fusen.yml