Check that the repositories given to "opam repository remove" actually exist

[kit-ty-kate]

Fixes #5012

[kit-ty-kate]

I've put back my original changes together with fixes to what needed fixing together with a couple of new tests.

Your original wip commit was 6a0b06e, i've also tried to improve the previous attempt in check-repos-remove-exist-old to no avail.
Given the increase of complexity of solutions that do not use ref i don't think it's worth demonizing references for such a local and non-performance-cricical use, and I think this work is ready to be reviewed and merged.

[rjbou]

You don't want to load repository state to avoid having to load repositories to remove some ones ?

[kit-ty-kate]

updated

[kit-ty-kate]

rebased

[rjbou]

What do you think of

      OpamRepositoryState.with_ `Lock_write gt @@ fun rt ->
      if full_wipe then
        let repos =
          OpamRepositoryName.Map.keys rt.OpamStateTypes.repositories
        in
        check_for_repos repos names
          (OpamConsole.warning
             "No configured repositories by these names found: %s");
        OpamRepositoryState.drop @@
        List.fold_left OpamRepositoryCommand.remove rt names
      else begin
        let has_known_repos =
          List.fold_left (fun has_known_repos switch ->
              let repos = OpamRepositoryCommand.switch_repos rt switch in
              check_for_repos' repos names
                (OpamConsole.warning
                   "No configured repositories by these names found in \
                    the selection of switch '%s': %s"
                   (OpamSwitch.to_string switch))
              || has_known_repos)
            false switches
        in
        if scope = [`Current_switch] && has_known_repos then
          OpamConsole.msg
            "Repositories removed from the selections of switch %s. \
             Use '--all' to forget about them altogether.\n"
            (OpamSwitch.to_string (OpamStateConfig.get_switch ()))
      end;
      let rm =
        List.filter (fun n ->
            not (List.exists (OpamRepositoryName.equal n) names))
      in
      ignore @@ OpamRepositoryCommand.update_selection gt
        ~global ~switches:switches rm;
      `Ok ()

diff
The idea is to factorise some code and make it more step by step, more "readable":

• first loading repostate
• then check availability, display comments, and remove in global case (take advantage of the if)
• then for all, update switch selection (no need to drop as it is in an with_ function
• end

[kit-ty-kate]

I incorporated this diff except for the factorization of the repo-state loading as it would load it in write mode regardless of need (non full_wipe do not need it to be in write mode)

[rjbou]

bien vu!

[kit-ty-kate]

updated