feat: Add versioning to plugin add command

Allows user to specify version along with URL when adding plugin to lock
to a specific version instead of always relying on HEAD.

Relates to #234

lib/commands/command-plugin-add.bash

@@ -1,12 +1,13 @@
 # -*- sh -*-
 
 plugin_add_command() {
-  if [[ $# -lt 1 || $# -gt 2 ]]; then
-    display_error "usage: asdf plugin-add <name> [<git-url>]"
+  if [[ $# -lt 1 || $# -gt 3 ]]; then
+    display_error "usage: asdf plugin-add <name> [<git-url>] [<git-ref>]"
     exit 1
   fi
 
   local plugin_name=$1
+  local plugin_ref=""
 
   if [ -n "$2" ]; then
     local source_url=$2
@@ -16,6 +17,11 @@ plugin_add_command() {
     source_url=$(get_plugin_source_url "$plugin_name")
   fi
 
+  if [ -n "$3" ]; then
+    plugin_ref="$3"
+    plugin_name=$plugin_name-$3
+  fi
+
   if [ -z "$source_url" ]; then
     display_error "plugin $plugin_name not found in repository"
     exit 1
@@ -33,8 +39,14 @@ plugin_add_command() {
     asdf_run_hook "pre_asdf_plugin_add" "$plugin_name"
     asdf_run_hook "pre_asdf_plugin_add_${plugin_name}"
 
-    if ! git clone -q "$source_url" "$plugin_path"; then
-      exit 1
+    if [ -z "$plugin_ref" ]; then
+      if ! git clone -q "$source_url" "$plugin_path"; then
+        exit 1
+      fi
+    else
+      if ! git clone -q -b "$plugin_ref" "$source_url" "$plugin_path"; then
+        exit 1
+      fi
     fi
 
     if [ -f "${plugin_path}/bin/post-plugin-add" ]; then

test/plugin_add_command.bats

@@ -30,6 +30,20 @@ teardown() {
   [ "$output" = "dummy" ]
 }
 
+@test "plugin_add command with URL and git-ref specified adds a plugin using repo" {
+  install_mock_plugin_repo_with_ref "dummy"
+
+  run asdf plugin-add "dummy" "${BASE_DIR}/repo-dummy" "tagname"
+  [ "$status" -eq 0 ]
+
+  repo_head="$(git --git-dir "${BASE_DIR}/repo-dummy/.git" --work-tree "$ASDF_DIR/plugins/dummy" describe --tags)"
+  [ "$status" -eq 0 ]
+  [ "$repo_head" = "tagname" ]
+
+  run asdf plugin-list
+  [ "$output" = "dummy-tagname" ]
+}
+
 @test "plugin_add command with URL specified run twice returns error second time" {
   install_mock_plugin_repo "dummy"
 

test/test_helpers.bash

@@ -44,6 +44,13 @@ install_mock_plugin_repo() {
   git -C "${location}" commit -q -m "asdf ${plugin_name} plugin"
 }
 
+install_mock_plugin_repo_with_ref() {
+  install_mock_plugin_repo $1
+  local plugin_name=$1
+  local location="${BASE_DIR}/repo-${plugin_name}"
+  git -C "${location}" tag "tagname"
+}
+
 install_mock_plugin_version() {
   local plugin_name=$1
   local plugin_version=$2