(devel/R-usethis) Updated 1.6.3 to 2.0.0, sorry for long log

See also:
 https://www.tidyverse.org/blog/2020/12/usethis-2-0-0/

# usethis 2.0.0

This version is anticipated to be released as usethis v2.0.0.

## Adoption of gert and changes to Git/GitHub credential handling

Usethis has various functions that help with Git-related tasks, which
break down into two categories:

1. Git tasks, such as clone, push, and pull. These are things you
   could do with command line Git.

1. GitHub tasks, such as fork, release, and open an issue or pull
   request. These are things you could do in the browser or with the
   GitHub API.

We've switched from git2r to the gert package for Git operations
(<https://docs.ropensci.org/gert/>). We continue to use the gh package
for GitHub API work (<https://gh.r-lib.org>).

The big news in this area is that these lower-level dependencies are
getting better at finding Git credentials, finding the same
credentials as command line Git (and, therefore, the same as RStudio),
and finding the same credentials as each other. This allows usethis to
shed some of the workarounds we have needed in the past, to serve as a
remedial "credential valet".

Under the hood, both gert and gh are now consulting your local Git
credential store, when they need credentials. At the time of writing,
they are using two different even-lower-level packages to do this:

* gert uses the credentials package (<https://docs.ropensci.org/credentials/>)
* gh uses the gitcreds package (<https://gitcreds.r-lib.org/>)

Even now, gert and gh should discover the same credentials, at least
for github.com. In the future, these two packages may merge into one.

Git/GitHub credential management is covered in a new article:

[Managing Git(Hub)
Credentials](https://usethis.r-lib.org/articles/articles/git-credentials.html)

The main user-facing changes in usethis are:

* usethis should discover and use the same credentials as command line Git.
* usethis should be able to work with any GitHub deployment. While
  github.com is the default, GitHub Enterprise deployments are fully
  supported. The target GitHub host is determined from the current
  project's configured GitHub remotes, whenever possible.

As a result, several functions are deprecated and several other
functions have some deprecated arguments.

* Deprecated functions:
  - `use_git_credentials()`
  - `git_credentials()`
  - `github_token()`
* Functions with (deprecated arguments):
  - `create_from_github()` (`auth_token`, `credentials`)
  - `use_github()` (`auth_token`, `credentials`)
  - `use_github_links()` (`host`, `auth_token`)
  - `use_github_labels()` (`repo_spec`, `host`, `auth_token`)
  - `use_tidy_labels()` (`repo_spec`, `host`, `auth_token`)
  - `use_github_release()` (`host`, `auth_token`)

The switch to gert + credentials should eliminate most
credential-finding fiascos. Gert also takes a different approach to
wrapping libgit2, the underlying C library that does Git
operations. The result is more consistent support for SSH and TLS,
across all operating systems, without requiring special effort at
install time. More users should enjoy Git remote operations that "just
work", for both SSH and HTTPS remotes. There should be fewer
"unsupported protocol" errors.

## GitHub remote configuration

Usethis gains a more formal framework for characterizing a GitHub
remote configuration. We look at:

  * Which GitHub repositories `origin` and `upstream` point to
  * Whether you can push to them
  * How they relate to each other, e.g. fork-parent relationship

This is an internal matter, but users will notice that usethis is more
clear about which configurations are supported by various functions
and which are not. The most common configurations are reviewed in a
[section of Happy
Git](https://happygitwithr.com/common-remote-setups.html).

When working in a fork, there is sometimes a question whether to
target the fork or its parent repository. For example,
`use_github_links()` adds GitHub links to the URL and BugReports
fields of DESCRIPTION. If someone calls `use_github_links()` when
working in a fork, they probably want those links to refer to the
*parent* or *source* repo, not to their fork, because the user is
probably preparing a pull request. Usethis should now have better
default behaviour in these situations and, in some cases, will present
an interactive choice.

## Default branch

There is increasing interest in making the name of a repo's default
branch configurable. Specifically, `main` is emerging as a popular
alternative to `master`. Usethis now discovers the current repo's
default branch and uses that everywhere that, previously, we had
hard-wired `master`.

`git_branch_default()` is a newly exported function that is also what's used internally.

`use_course()`, `use_zip()`, and `create_download_url()` all have some
support for forming the URL to download a `.zip` archive of a repo,
based on a repo specification (e.g. `OWNER/REPO`) or a browser
URL. These helpers now form a URL that targets `HEAD` of the repo,
i.e. the default branch.

## Changes to Git/GitHub functionality

The default Git protocol is now "https" and we no longer provide an
interactive choice, by default, in interactive sessions. As always, a
user can express a preference for "ssh" in individual function calls,
for an R session via `use_git_protocol()`, and for all R sessions via
the `usethis.protocol` option (#1262).

`pr_resume()` is a new function for resuming work on an existing local
PR branch. It can be called argument-less, to select a branch
interactively.

`pr_fetch()` can also be called with no arguments, to select a PR
interactively.  The `owner` argument is replaced by `target`, with a
choice of the source (default) or primary repo.

`pr_forget()` is a new function for abandoning a PR you initiated
locally or fetched from GitHub. It only does local clean up and, for
example, doesn't delete a remote branch or close a PR (#1263).

`pr_view()` can now be called with no arguments. If the current branch
is associated with an open PR, we target that and, otherwise, we offer
an interactive selection.

`pr_finish()` deletes the remote PR branch if the PR has been merged
and the current user has the power to do so, i.e. an external
contributor deleting their own branch or a maintainer deleting a
branch associated with an internal PR (#1150). It no longer errors if
the PR branch has already been deleted (#1196).

`pr_pull_upstream()` is renamed to `pr_merge_main()` to emphasize that
it merges the **main** line of development into the current branch,
where the main line of development is taken to mean the default
branch, as reported by `git_branch_default()`, of the source repo,
which could be either `upstream` or `origin`, depending on the
situation.

`create_from_github()` will only create a read-only clone, due to lack
of a GitHub personal access token, if explicitly directed to do so via
`fork = FALSE`.

`create_from_github()` and `use_tidy_thanks()` accept browser and Git
URLs as the `repo_spec` argument, to be friendlier to copy/paste. When
a URL is passed, the `host` is also extracted from it.

`create_github_token()` is a new name for the function previously
known as `browse_github_token()` and `browse_github_pat()`.

`issue_close_community()` and `issue_reprex_needed()` are two new
functions for maintainers who process lots of GitHub issues. They
automate canned replies and actions, e.g. labelling or closing (#940).

GitHub Actions is the preferred platform for continuous integration,
because that is what the tidyverse team currently uses and
maintains. Functions related to Travis-CI and AppVeyor are
soft-deprecated to raise awareness about this change and to make it
clear that, if substantial maintenance becomes necessary, we may elect
to retire the function (#1169).

`browse_github_actions()` is a new function to open the Actions page
of the respective repo on GitHub, similar to existing `browse_*()`
functions (@pat-s, #1102).

`use_github_pages()` is a new function to activate or reconfigure the
GitHub Pages site associated with a repository (#224).

`use_tidy_pkgdown()` implements the complete pkgdown configuration
used by the tidyverse team (#224).

`pr_sync()` is defunct and can be replicated by calling `pr_pull()`,
`pr_merge_main()`, then `pr_push()`.

## Licensing improvements

All `use_*_license()` functions now work for projects, not just
packages.

`use_apl2_license()` (not `use_apache_license()`) and
`use_gpl3_license()` no longer modify the license text (#1198).

`use_mit_license()` now sets the default copyright holder to
"{package} authors". This makes it more clear that the copyright
holders are the contributors to the package; unless you are using a
CLA there is no one copyright holder of a package (#1207).

New `use_gpl_license()` and `use_agpl_license()` make it easier to
pick specific versions of the GPL and AGPL licenses, and to choose
whether or not you include future versions of the license. Both
default to version 3 (and above).

New `use_proprietary_license()` allows your package to pass R CMD
check while making it clear that your code is not open source
(#1163). Thanks to @atheriel for the blog post suggesting the wording:
https://unconj.ca/blog/copyright-in-closed-source-r-packages-the-right-way.html

`use_lgpl_license()` now uses version 3 (and above), and gains new
`version` and `include_future` argument to control which version is
used.

`use_gpl3_license()`, `use_agpl3_license()` and `use_apl2_license()`
have been deprecated in favour of the new `version` argument to
`use_gpl_license()`, `use_agpl_license()` and `use_apache_license()`.

The `name` argument to `use_mit_license()` has been changed to
`copyright_holder` to make the purpose more clear. The `name` argument
has been removed from all other license functions because it is not
needed; no other license makes an assertion about who the copyright
holder is.

## RStudio preferences

usethis is now fully cognizant of the [changes to RStudio
preferences](https://blog.rstudio.com/2020/02/18/rstudio-1-3-preview-configuration/)
in RStudio 1.3:

`edit_rstudio_snippets()` looks in the new location, and if you have
snippets in the old location, will automatically copy them to the new
location (#1204)

New `edit_rstudio_prefs()` opens RStudio preferences file for editing
(#1148).

`use_blank_slate()` can now configure your global, i.e. user-level,
RStudio preference, in addition to project-level (#1018).

## Other changes

`browse_package()` and `browse_project()` are new functions that let
the user choose from a list of URLs derived from local Git remotes and
DESCRIPTION (local or possibly on CRAN) (#1113).

The legacy `"devtools.desc"` option is no longer consulted when
populating a new DESCRIPTION file. You must use the
`"usethis.description"` now (#1069).

`use_dev_package()` gains a `remote` parameter to allow you to specify
the remote. The existing behaviour, which adds an `OWNER/REPO` GitHub
remote, remains the default (#918, @ijlyttle).

`use_cpp11()` is a new function to set up an R package to use cpp11.

`create_package(roxygen = FALSE)` once again writes a valid NAMESPACE
file (and also has no Roxygen* fields in DESCRIPTION) (#1120).

`create_package()`, `create_project()`, `create_from_github()`, and
`proj_activate()` work better with relative paths, inside and outside
of RStudio (#1122, #954).

`use_testthat()` gains an edition argument to support testthat v3.0.0
  (#1185)

`use_version()` now updates `src/version.c` if it exists and contains
a line matching `PKG_version = "x.y.z";`.

usethis has been re-licensed as MIT (#1252, #1253).

## Dependency changes

New Imports: gert, jsonlite (was already an indirect dependency),
lifecycle, rappdirs

No longer in Imports: git2r, rematch2


(mef)