Fix install with submodules (#408)

* manage installation from a repo where there are submodules (+ update broken example from README)

* update NEWS.md file

NEWS.md

@@ -70,6 +70,8 @@
 
 * git submodules now work if the submodule file is empty (@muschellij2, #234)
 
+* git submodules now work if the R package is stored in a subfolder (@pommedeterresautee, #233)
+
 * `install_gitlab()` no longer adds the access token twice to the request
   (@aornugent, #363).
 

R/install-remote.R

@@ -58,7 +58,7 @@ install_remote <- function(remote,
   source <- source_pkg(bundle, subdir = remote$subdir)
   on.exit(unlink(source, recursive = TRUE), add = TRUE)
 
-  update_submodules(source, quiet)
+  update_submodules(source, remote$subdir, quiet)
 
   add_metadata(source, remote_metadata(remote, bundle, source, remote_sha))
 

R/submodule.R

@@ -84,10 +84,20 @@ update_submodule <- function(url, path, branch, quiet) {
   git(paste0(args, collapse = " "), quiet = quiet)
 }
 
-update_submodules <- function(source, quiet) {
+update_submodules <- function(source, subdir, quiet) {
   file <- file.path(source, ".gitmodules")
+
   if (!file.exists(file)) {
-    return()
+
+    if (!is.null(subdir)) {
+      nb_sub_folders <- lengths(strsplit(subdir, "/"))
+      source <- do.call(file.path, as.list(c(source, rep("..", nb_sub_folders))))
+    }
+
+    file <- file.path(source, ".gitmodules")
+    if (!file.exists(file)) {
+      return()
+    }
   }
   info <- parse_submodules(file)
 

README.md

@@ -87,7 +87,8 @@ If the R package is inside a subdirectory of the root directory,
 then give this subdirectory as well:
 
 ```r
-remotes::install_github("dmlc/xgboost/R-package")
+# build = FALSE because of some specificities of XGBoost package
+install_github("dmlc/xgboost/R-package", build = FALSE)
 ```
 
 To install a certain branch or commit or tag, append it to the

tests/testthat/test-submodule.R

@@ -117,7 +117,7 @@ test_that("Can install a repo with a submodule", {
 
   writeLines("^bar$", build_ignore)
 
-  update_submodules("submodule", quiet = TRUE)
+  update_submodules("submodule", NULL, quiet = TRUE)
   expect_true(dir.exists(file.path("submodule", "R")))
   expect_false(dir.exists(file.path("submodule", "bar")))
 
@@ -154,6 +154,6 @@ test_that("Can update a submodule with an empty .gitmodules submodule", {
 
   writeLines("^bar$", build_ignore)
 
-  update_submodules("submodule", quiet = TRUE)
+  update_submodules("submodule", NULL, quiet = TRUE)
 
 })