when attempting to load a lockfile and finding only a manifest, automatically generate a lockfile and load that

R/lockfile.R

@@ -122,7 +122,6 @@ renv_lockfile_save <- function(lockfile, project) {
 }
 
 renv_lockfile_load <- function(project, strict = FALSE) {
-
   path <- renv_lockfile_path(project)
   if (file.exists(path))
     return(renv_lockfile_read(path))
@@ -134,6 +133,13 @@ renv_lockfile_load <- function(project, strict = FALSE) {
     ))
   }
 
+  manifest <- file.path(project, "manifest.json")
+  if (file.exists(manifest)) {
+    caution("No lockfile found; creating from `manifest.json`.")
+    renv_lockfile_from_manifest(manifest, path)
+    return(renv_lockfile_read(path))
+  }
+
   renv_lockfile_init(project = project)
 
 }

R/manifest-convert.R

@@ -73,10 +73,8 @@ renv_lockfile_from_manifest <- function(manifest = "manifest.json",
   if (is.na(lockfile))
     return(lock)
 
-  # otherwise, write to file and report for user
+  # otherwise, write to file
   renv_lockfile_write(lock, file = lockfile)
-  fmt <- "- Lockfile written to %s."
-  writef(fmt, renv_path_pretty(lockfile))
 
   invisible(lock)
 

R/paths.R

@@ -66,7 +66,7 @@ renv_paths_lockfile <- function(project = NULL) {
     return(override)
   }
 
-  # otherwise, use default location (location location relative to renv folder)
+  # otherwise, use default location (location relative to renv folder)
   project <- renv_project_resolve(project)
   renv <- renv_paths_renv(project = project)
   file.path(dirname(renv), "renv.lock")

tests/testthat/test-lockfile.R

@@ -49,6 +49,28 @@ test_that("we can create lockfiles from manifests", {
 
 })
 
+test_that("we create lockfile from a manifest automatically when no lockfile found", {
+
+  skip_on_cran()
+
+  project_dir <- tempfile()
+  dir.create(project_dir)
+
+  manifest <- "resources/manifest.json"
+  expected_lock <- renv_lockfile_from_manifest("resources/manifest.json")
+  file.copy(manifest, file.path(project_dir, "manifest.json"))
+
+  # when called with `strict = TRUE` does not create manifest
+  expect_error(renv_lockfile_load(project_dir, strict = TRUE))
+
+  # creates and reads lockfile
+  obtained_lock <- renv_lockfile_load(project_dir)
+  expect_identical(expected_lock, obtained_lock)
+  expect_true(file.exists(file.path(project_dir, "renv.lock")))
+
+  unlink(project_dir, recursive = TRUE)
+})
+
 test_that("the Requirements field is read as character", {
 
   lockfile <- renv_lockfile_read(text = '