prune yarn devDependencies at the end of build (heroku#891)

* prune yarn devDependencies at the end of build * Remove warning message for production flag * Update tests to reflect need of workspace import * install workspace plugin when not present * update fixtures * cache build with yarn 2 * change grep of yarn plugins from yarnrc.yml; delete warning test for production flag * set up buildpack to instead warn that plugin is missing and prompt user to install before build

Author: danielleadams

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Node.js Buildpack Changelog
 
 ## main
+- Prune devDependencies with Yarn 2 ([#891](https://github.com/heroku/heroku-buildpack-nodejs/pull/891))
 
 ## v183 (2020-02-03)
 - Update node version to 14 ([#885](https://github.com/heroku/heroku-buildpack-nodejs/pull/885))

bin/compile

@@ -145,8 +145,6 @@ export YARN_CACHE_FOLDER NPM_CONFIG_CACHE
 export VENDOR_PATH
 
 if [[ "$YARN_2" == "true" ]]; then
- fail_yarn_2_production "$BUILD_DIR"
-
  if [[ "$NODE_MODULES_CACHE" == "true" ]] && ! node_modules_enabled "$BUILD_DIR"; then
  warn "
  The buildpack won't cache the dependencies in .yarn/cache. Since you're using Yarn 2 and Plug'n'Play, you will need to customize your cache or unset NODE_MODULES_CACHE." "https://devcenter.heroku.com/articles/migrating-to-yarn-2#disable-dependency-caching"
@@ -348,22 +346,20 @@ cache_build() {
 }
 
 prune_devdependencies() {
- if $YARN; then
- yarn_prune_devdependencies "$BUILD_DIR"
+ if $YARN || $YARN_2; then
+ yarn_prune_devdependencies "$BUILD_DIR" "$YARN_CACHE_FOLDER"
  else
  npm_prune_devdependencies "$BUILD_DIR"
  fi
 }
 
-# if we are using yarn
-# and in the new feature
-# and we're using the default cache directories
-# then save off the cache after we prune out devDepenencies
-if [[ "$YARN_2" == "true" ]]; then
+if $YARN_2; then
+ meta_set "build-step" "save-cache"
  cache_build | output "$LOG_FILE"
  meta_set "build-step" "prune-dependencies"
- meta_set "build-step" "save-cache"
-elif [[ "$YARN" == "true" ]] && [[ "$USE_YARN_CACHE" == "true" ]] && [[ "$(get_cache_directories "$BUILD_DIR")" == "" ]]; then
+ header "Pruning devDependencies" | output "$LOG_FILE"
+ prune_devdependencies | output "$LOG_FILE"
+elif "$YARN" && "$USE_YARN_CACHE" && [[ "$(get_cache_directories "$BUILD_DIR")" == "" ]]; then
  meta_set "build-step" "prune-dependencies"
  header "Pruning devDependencies" | output "$LOG_FILE"
  prune_devdependencies | output "$LOG_FILE"

lib/dependencies.sh

@@ -156,6 +156,8 @@ yarn_2_install() {
 
 yarn_prune_devdependencies() {
  local build_dir=${1:-}
+ local cache_dir=${2:-}
+ local workspace_plugin_path
 
  if [ "$NODE_ENV" == "test" ]; then
  echo "Skipping because NODE_ENV is 'test'"
@@ -169,6 +171,21 @@ yarn_prune_devdependencies() {
  echo "Skipping because YARN_PRODUCTION is '$YARN_PRODUCTION'"
  meta_set "skipped-prune" "true"
  return 0
+ elif $YARN_2; then
+ cd "$build_dir" || return
+
+ if has_yarn_workspace_plugin_installed "$build_dir"; then
+ meta_set "workspace-plugin-present" "true"
+
+ # The cache is removed beforehand because the command is running an install on devDeps, and
+ # it will not remove the existing dependencies beforehand.
+ rm -rf "$cache_dir"
+ monitor "yarn-prune" yarn workspaces focus --all --production
+ meta_set "skipped-prune" "false"
+ else
+ meta_set "workspace-plugin-present" "false"
+ echo "Skipping because the Yarn workspace plugin is not present. Add the plugin to your source code with 'yarn plugin import workspace-tools'."
+ fi
  else
  cd "$build_dir" || return
  monitor "yarn-prune" yarn install --frozen-lockfile --ignore-engines --ignore-scripts --prefer-offline 2>&1

lib/failure.sh

@@ -418,18 +418,6 @@ fail_missing_yarn_vendor() {
  fi
 }
 
-fail_yarn_2_production() {
- local build_dir="$1"
-
- if [[ -n "$YARN_PRODUCTION" ]]; then
- header "Build failed"
- warn "
- The --production flag is no longer used for installing production dependencies for entire projects, but is still used in workspaces. See https://devcenter.heroku.com/articles/migrating-to-yarn-2#update-heroku-environment-with-plug-n-play-remove-production-environment-variables for additional information.
- "
- fail
- fi
-}
-
 log_other_failures() {
  local log_file="$1"
  if grep -qi "sh: 1: .*: not found" "$log_file"; then

lib/yarn-2.sh

@@ -22,10 +22,20 @@ detect_yarn_2() {
 
 has_yarn_cache() {
  local build_dir="$1"
-
  [[ -d "$build_dir/.yarn/cache" ]]
 }
 
+has_yarn_workspace_plugin_installed() {
+ local build_dir="$1"
+ local plugin_paths=$(get_yarn_plugin_paths "$build_dir")
+ [[ ! -n $plugin_paths ]] && echo "$plugin_paths" | grep plugin-workspace-tools
+}
+
+get_yarn_plugin_paths() {
+ local build_dir="$1"
+ $YQ r "$build_dir/.yarnrc.yml" "plugins.[*].path" 2>&1
+}
+
 get_yarn_path() {
  local build_dir="$1"
  $YQ r "$build_dir/.yarnrc.yml" yarnPath 2>&1

test/fixtures/yarn-2-with-node-modules/package.json

@@ -9,8 +9,5 @@
  },
  "devDependencies": {
  "debug": "^4.1.1"
- },
- "scripts": {
- "build": "tsc --version"
  }
 }