fix move_folder_contents (#13873)

* fix move_folder_contents

* rename arg

conan/tools/files/files.py

@@ -543,11 +543,10 @@ def collect_libs(conanfile, folder=None):
     return result
 
 
-# TODO: Do NOT document this yet. It is unclear the interface, maybe should be split
-def move_folder_contents(src_folder, dst_folder):
-    """ replaces the current folder contents with the contents of one child folder. This
-    is used in the SCM monorepo flow, when it is necessary to use one subproject subfolder
-    to replace the whole cloned git repo
+def move_folder_contents(conanfile, src_folder, dst_folder):
+    """ replaces the dst_folder contents with the contents of the src_folder, which can be a
+    child folder of dst_folder. This is used in the SCM monorepo flow, when it is necessary
+    to use one subproject subfolder to replace the whole cloned git repo
     /base-folder                       /base-folder
         /pkg  (src folder)                 /other/<otherfiles>
           /other/<otherfiles>              /pkg/<pkgfiles>

conans/test/functional/tools/scm/test_git.py

@@ -510,7 +510,7 @@ def source(self):
                 sources = self.conan_data["sources"]
                 git.clone(url=sources["url"], target=".")
                 git.checkout(commit=sources["commit"])
-                move_folder_contents(os.path.join(self.source_folder, sources["folder"]),
+                move_folder_contents(self, os.path.join(self.source_folder, sources["folder"]),
                                     self.source_folder)
 
             def build(self):
@@ -598,7 +598,7 @@ def source(self):
                     # Final we want is pkg/<files> and common/<files>
                     # NOTE: This abs_path is IMPORTANT to avoid the trailing "."
                     src_folder = os.path.abspath(self.source_folder)
-                    move_folder_contents(src_folder, os.path.dirname(src_folder))
+                    move_folder_contents(self, src_folder, os.path.dirname(src_folder))
 
                 def build(self):
                     cmake = CMake(self)