🧑‍💻 Improve bundler setup for Devcontainer

Author: pboling

.devcontainer/2.5/apt-install/devcontainer-feature.json

@@ -0,0 +1,9 @@
+{
+  "name": "Bundle Config",
+  "id": "bundle-config",
+  "version": "1.0.0",
+  "description": "Bundle Config",
+  "install": {
+    "script": "install.sh"
+  }
+}

.devcontainer/2.5/apt-install/install.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+RUBYGEMS_VERSION=3.3.27
+gem install rubygems-update -v ${RUBYGEMS_VERSION} > /dev/null 2>&1 &&
+update_rubygems > /dev/null 2>&1
+# Ensure we use the right Gemfile
+echo 'export BUNDLE_GEMFILE=Gemfile-ruby2_5.gemfile' >> ~/.bashrc

.devcontainer/2.5/bundle-config/devcontainer-feature.json

@@ -3,12 +3,12 @@
 {
   "name": "Ruby 2.5 on Debian",
   "image": "ruby:2.5-buster",
-  "postCreateCommand": "RUBYGEMS_VERSION=3.3.27\ngem install rubygems-update -v ${RUBYGEMS_VERSION} > /dev/null 2>&1 &&\nupdate_rubygems > /dev/null 2>&1 &&\nbundle install",
+  "postCreateCommand": "bundle install",
 
   // Features to add to the dev container. More info: https://containers.dev/features.
   // Features run during the image build, and thus before the lifecycle hooks in this file, e.g., postCreateCommand
   "features": {
-    "./apt-install": {}
+    "./bundle-config": {}
   },
 
   // Configure tool-specific properties.

.devcontainer/2.5/bundle-config/install.sh

@@ -6,7 +6,6 @@ git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
 gemspec
 
 group :development do
-  gem "bundler"
   # This is for suppressing the following warning:
   #
   #   warning: ostruct was loaded from the standard library, but will

.devcontainer/2.5/devcontainer.json

@@ -0,0 +1,28 @@
+source "https://rubygems.org"
+
+git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
+
+# Specify your gem's dependencies in rexml.gemspec
+gemspec
+
+group :development do
+  # This is for suppressing the following warning:
+  #
+  #   warning: ostruct was loaded from the standard library, but will
+  #   no longer be part of the default gems starting from Ruby 3.5.0.
+  #
+  # This should be part of "json". We can remove this when "json"
+  # depends on "ostruct" explicitly.
+  gem "ostruct"
+  gem "rake"
+  gem "rdoc"
+end
+
+group :benchmark do
+  gem "benchmark_driver"
+end
+
+group :test do
+  gem "test-unit"
+  gem "test-unit-ruby-core"
+end