Use httr conditionally (#2574)

* Use httr conditionally

* Tweak NEWS

---------

Co-authored-by: Jenny Bryan <[email protected]>

Author: catalamarti

Diff for: NEWS.md

@@ -1,5 +1,8 @@
 # devtools (development version)
 
+* Functions that use httr now explicitly check that it is installed
+  (@catalamarti, #2573).
+
 * `test_coverage()` now works if the package has not been installed.
 
 * `test_coverage_active_file()` now reports if any tests failed and does

Diff for: R/check-mac.R

@@ -40,6 +40,7 @@ check_mac_release <- function(pkg = ".", dep_pkgs = character(), args = NULL, ma
 
   url <- "https://mac.r-project.org/macbuilder/v1/submit"
 
+  rlang::check_installed("httr")
   body <- list(pkgfile = httr::upload_file(built_path))
 
   if (length(dep_built_paths) > 0) {

Diff for: R/release.R

@@ -277,6 +277,7 @@ upload_cran <- function(pkg, built_path, call = parent.frame()) {
 
   # Initial upload ---------
   cli::cli_inform(c(i = "Uploading package & comments"))
+  rlang::check_installed("httr")
   body <- list(
     pkg_id = "",
     name = maint$name,

Diff for: R/run-source.R

@@ -31,6 +31,7 @@
 source_url <- function(url, ..., sha1 = NULL) {
   stopifnot(is.character(url), length(url) == 1)
   rlang::check_installed("digest")
+  rlang::check_installed("httr")
 
   temp_file <- file_temp()
   on.exit(file_delete(temp_file), add = TRUE)