use 'snapshot(reprex = TRUE)' to embed lockfile in reprex

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: renv
 Type: Package
 Title: Project Environments
-Version: 0.12.5-7
+Version: 0.12.5-9
 Authors@R: c(
     person("Kevin", "Ushey", role = c("aut", "cre"), email = "[email protected]"),
     person("RStudio", role = c("cph"))

NEWS.md

@@ -1,6 +1,11 @@
 
 # renv 0.13.0 (UNRELEASED)
 
+* `renv::snapshot()` gains the `reprex` argument. Set this to `TRUE` if you'd
+  like to embed an `renv` lockfile as part of a reproducible example, as
+  generated by the [`reprex`](https://www.tidyverse.org/help/#reprex-pkg)
+  package.
+
 * `renv::status()` now reports packages that are referenced in a project's
   scripts, but are neither installed in the project library nor recorded in the
   lockfile. (#588)

R/snapshot.R

@@ -82,6 +82,9 @@
 #' @param force Boolean; force generation of a lockfile even when pre-flight
 #'   validation checks have failed?
 #'
+#' @param reprex Boolean; generate output appropriate for embedding the lockfile
+#'   as part of a [reprex](https://www.tidyverse.org/help/#reprex)?
+#'
 #' @return The generated lockfile, as an \R object (invisibly). Note that
 #'   this function is normally called for its side effects.
 #'
@@ -97,7 +100,8 @@ snapshot <- function(project  = NULL,
                      type     = settings$snapshot.type(project = project),
                      packages = NULL,
                      prompt   = interactive(),
-                     force    = FALSE)
+                     force    = FALSE,
+                     reprex   = FALSE)
 {
   renv_consent_check()
   renv_scope_error_handler()
@@ -127,6 +131,10 @@ snapshot <- function(project  = NULL,
   if (is.null(lockfile))
     return(new)
 
+  # if running as part of 'reprex', then render output inline
+  if (reprex)
+    return(renv_snapshot_reprex(new))
+
   # TODO: do we still want to snapshot if the user cancels
   # the R-level snapshot?
   on.exit(renv_python_snapshot(project), add = TRUE)
@@ -907,3 +915,26 @@ renv_snapshot_fixup_renv <- function(records) {
   # nocov end
 
 }
+
+renv_snapshot_reprex <- function(lockfile) {
+
+  fmt <- "<sup>Lockfile generated by renv %s.</sup>"
+  version <- sprintf(fmt, renv_package_version("renv"))
+
+  text <- c(
+    "<details style=\"margin-bottom: 10px;\">",
+    "<summary>Lockfile</summary>",
+    "```",
+    renv_lockfile_write(lockfile, file = NULL),
+    "```",
+    version,
+    "</details>"
+  )
+
+  output <- paste(text, collapse = "\n")
+  class(output) <- "knit_asis"
+  attr(output, "knit_cacheable") <- NA
+
+  output
+
+}