chore(scripts): builddown should use foreach to support resuming buil…

…ds (#8784)

buildup and builddown currently use two entirely different approaches.
This fix makes the builddown mirror the current buildup script, and alters foreach to
support a --down flag in addition to --up.


----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

scripts/builddown

@@ -1,14 +1,27 @@
 #!/bin/bash
 set -euo pipefail
+scriptdir=$(cd $(dirname $0) && pwd)
+
+echo "************************************************************"
+echo " builddown usage:"
+echo " - execute 'builddown --resume' to resume after failure"
+echo " - execute 'builddown' to restart the build from the start"
+echo ""
+echo " for advanced usage, see ${scriptdir}/foreach.sh"
+echo "************************************************************"
 
-if ! [ -x "$(command -v yarn)" ]; then
-  echo "yarn is not installed. Follow the guide to install yarn - https://yarnpkg.com/en/docs/install."
-  exit 1
+if [ "$#" -eq 0 ]; then
+  ${scriptdir}/foreach.sh --reset
+else
+  if [ "$1" != "--resume" ]; then
+    echo "Unknown option: $1"
+    exit 1
+  fi
 fi
 
-export NODE_OPTIONS="--max-old-space-size=4096 ${NODE_OPTIONS:-}"
+${scriptdir}/foreach.sh --down yarn build
+${scriptdir}/foreach.sh --reset
 
-scriptdir=$(cd $(dirname $0) && pwd)
-export PATH=$(cd $scriptdir && npm bin):$PATH
-scope=$(${scriptdir}/current-scope)
-exec lerna run ${1:-build} --scope ${scope} --include-dependents
+echo "************************************************************"
+echo "builddown done"
+echo "************************************************************"

scripts/foreach.sh

@@ -18,6 +18,9 @@
 # to run the command only against the current module and its dependencies:
 #     foreach.sh --up COMMAND
 #
+# to run the command only against the current module and its consumers:
+#     foreach.sh --down COMMAND
+#
 # --------------------------------------------------------------------------------------------------
 set -euo pipefail
 scriptdir=$(cd $(dirname $0) && pwd)
@@ -61,17 +64,24 @@ if [[ "${1:-}" == "--skip" ]]; then
     exit 0
 fi
 
-up=""
-up_desc=""
-if [[ "${1:-}" == "--up" ]]; then
+direction=""
+direction_desc=""
+if [[ "${1:-}" == "--up" || "${1:-}" == "--down" ]]; then
     if [ ! -f package.json ]; then
-      echo "--up can only be executed from within a module directory (looking for package.json)"
+      echo "--up or --down can only be executed from within a module directory (looking for package.json)"
       exit 1
     fi
 
     scope=$(node -p "require('./package.json').name")
-    up=" --scope ${scope} --include-dependencies"
-    up_desc="('${scope}' and its dependencies)"
+
+    if [[ "${1:-}" == "--up" ]]; then
+      direction=" --scope ${scope} --include-dependencies"
+      direction_desc="('${scope}' and its dependencies)"
+    else # --down
+      direction=" --scope ${scope} --include-dependents"
+      direction_desc="('${scope}' and its consumers)"
+    fi
+
     shift
 fi
 
@@ -89,8 +99,8 @@ fi
 if [ ! -f "${statefile}" ] && [ ! -f "${commandfile}" ]; then
   if [ ! -z "${command_arg}" ]; then
     command="${command_arg}"
-    success "starting new session ${up_desc}"
-    ${scriptdir}/../node_modules/.bin/lerna ls --all ${up} --toposort -p > ${statefile}
+    success "starting new session ${direction_desc}"
+    ${scriptdir}/../node_modules/.bin/lerna ls --all ${direction} --toposort -p > ${statefile}
     echo "${command}" > ${commandfile}
   else
     error "no active session, use \"$(basename $0) COMMAND\" to start a new session"