Merge pull request #994 from heroku/revert/v193_yarn_dependency_pruning

Revert changes introduced in #990

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## main
 
+## v194 (2022-03-30)
+- Revert fix for pruning yarn 2 cache due to an edge case that would cause all devDependencies to be installed ([#990](https://github.com/heroku/heroku-buildpack-nodejs/pull/990))
+
 ## v193 (2022-03-28)
 - Added Yarn 1.22.18 to `inventory/yarn.toml` ([#992](https://github.com/heroku/heroku-buildpack-nodejs/pull/992))
 - Fix issue with pruning yarn 2 cache when using the workspaces plugin ([#990](https://github.com/heroku/heroku-buildpack-nodejs/pull/990))

lib/dependencies.sh

@@ -173,8 +173,10 @@ yarn_prune_devdependencies() {
       echo "Running 'yarn workspaces focus --all --production'"
       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 "$cache_dir"
       monitor "yarn-prune" yarn workspaces focus --all --production
-      yarn_prune_devdependencies_for_each_workspace "$build_dir"
       meta_set "skipped-prune" "false"
     else
       meta_set "workspace-plugin-present" "false"
@@ -187,23 +189,6 @@ yarn_prune_devdependencies() {
   fi
 }
 
-# removing all devDependencies this way *should* work but it would be nice if yarn supported
-# devDependency pruning like npm does when running `npm install --production`
-yarn_prune_devdependencies_for_each_workspace() {
-  local build_dir=${1:-}
-  local workspace_list=$(yarn workspaces list --json)
-  while IFS= read -r workspace; do
-    local name=$(echo "${workspace}" | jq -r '.name')
-    local location=$(echo "${workspace}" | jq -r '.location')
-    local devDependencies=$(cat "${build_dir}/${location}/package.json" | jq -r '.devDependencies | try keys | join(" ")')
-    if [ "${location}" == "." ]; then
-      monitor "yarn-prune" yarn remove ${devDependencies}
-    else
-      monitor "yarn-prune" yarn workspace "${name}" remove ${devDependencies}
-    fi
-  done <<< "${workspace_list}"
-}
-
 has_npm_lock() {
   local build_dir=${1:-}