fix(ws-cache): using a tmp dir for workspace locations file & better …

…handling of node_modules cache move out

run-build-functions.sh

@@ -60,6 +60,10 @@ mkdir -p $NETLIFY_CACHE_DIR/.gimme_cache/gocache
 mkdir -p $NETLIFY_CACHE_DIR/.homebrew-cache
 mkdir -p $NETLIFY_CACHE_DIR/.cargo
 
+
+# tmp dir
+NETLIFY_TMP_DIR=$(mktemp -d)
+
 : ${YARN_FLAGS=""}
 : ${NPM_FLAGS=""}
 : ${BUNDLER_FLAGS=""}
@@ -106,7 +110,8 @@ run_yarn() {
   if [ "$NETLIFY_YARN_WORKSPACES" = "true" ]
   then
     echo "NETLIFY_YARN_WORKSPACES feature flag set"
-    # Ignore path env var required in order to support yarn 2 projects
+    # YARN_IGNORE_PATH will ignore the presence of a local yarn executable (i.e. yarn 2) and default
+    # to using the global one (which, for now, is alwasy yarn 1.x). See https://yarnpkg.com/configuration/yarnrc#ignorePath
     if YARN_IGNORE_PATH=1 yarn workspaces info
     then
       # Extract all the packages and respective locations. .data will be a JSON object like
@@ -697,14 +702,17 @@ install_dependencies() {
 #
 cache_artifacts() {
   echo "Caching artifacts"
-  if [ "$NETLIFY_YARN_WORKSPACES" == "true" ] && [ -f package.json ]
-  then
-    cache_js_workspaces
-  fi
 
   cache_cwd_directory ".bundle" "ruby gems"
   cache_cwd_directory "bower_components" "bower components"
-  cache_cwd_directory "node_modules" "node modules"
+
+  if [ "$NETLIFY_YARN_WORKSPACES" == "true" ]
+  then
+    cache_node_modules
+  else
+    cache_cwd_directory "node_modules" "node modules"
+  fi
+
   cache_cwd_directory ".venv" "python virtualenv"
   cache_cwd_directory ".build" "swift build"
   cache_cwd_directory ".netlify/plugins" "build plugins"
@@ -829,7 +837,20 @@ restore_js_workspaces_cache() {
   # Retrieve hoisted node_modules
   move_cache "$cache_dir/node_modules" "$NETLIFY_REPO_DIR/node_modules" "restoring workspace root node modules"
   # Keep a record of the workspaces in the project in order to cache them later
-  echo "${locations[@]}" > "$cache_dir/.workspace_locations"
+  echo "${locations[@]}" > "$NETLIFY_TMP_DIR/.workspace_locations"
+}
+
+#
+# Caches node_modules dirs for a js project. Either detects the presence of js workspaces
+# via the `.workspace_locations` file, or looks at the node_modules in the cwd.
+#
+cache_node_modules() {
+  if [ -f "$NETLIFY_TMP_DIR/.workspace_locations" ]
+  then
+    cache_js_workspaces
+  else
+    cache_cwd_directory "node_modules" "node modules"
+  fi
 }
 
 #
@@ -838,16 +859,13 @@ restore_js_workspaces_cache() {
 #
 cache_js_workspaces() {
   local cache_dir="$NETLIFY_CACHE_DIR/js-workspaces"
-  if [ -f "$cache_dir/.workspace_locations" ]
-  then
-    local locations=($(cat "$cache_dir/.workspace_locations"))
-    for location in "${locations[@]}"; do
-      mkdir -p "$cache_dir/$location"
-      move_cache "$NETLIFY_REPO_DIR/$location/node_modules" "$cache_dir/$location/node_modules" "saving workspace $location node modules"
-    done
-    # Retrieve hoisted node_modules
-    move_cache "$NETLIFY_REPO_DIR/node_modules" "$cache_dir/node_modules" "saving workspace root node modules"
-  fi
+  local locations=($(cat "$NETLIFY_TMP_DIR/.workspace_locations"))
+  for location in "${locations[@]}"; do
+    mkdir -p "$cache_dir/$location"
+    move_cache "$NETLIFY_REPO_DIR/$location/node_modules" "$cache_dir/$location/node_modules" "saving workspace $location node modules"
+  done
+  # Retrieve hoisted node_modules
+  move_cache "$NETLIFY_REPO_DIR/node_modules" "$cache_dir/node_modules" "saving workspace root node modules"
 }
 
 cache_cwd_directory() {