Add yarn custom path and cache layer

CHANGELOG.md

@@ -4,6 +4,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 # main
 
+## 0.1.2 (2021-07-08)
+### Added
+- Add cache layer for yarn build
+- Allow run build from a specific path
+
 ## 0.1.1 (2021-03-28)
 ### Added
 - Add node requirement to build plan ([#7](https://github.com/heroku/nodejs-yarn-buildpack/pull/7))

README.md

@@ -35,6 +35,16 @@ cd .. # change from nodejs-npm-buildpack directory
 git clone [email protected]:heroku/nodejs-engine-buildpack.git
 ```
 
+### Define a custom path for yarn (optional)
+
+You can optionally create a `yarn.lock` file in the root directory with a line like this:
+
+```
+# yarn_path:public/my-custom-path
+```
+
+Make sure you place the actual `package.json` and `yarn.lock` in that path
+
 ### Build the image
 
 #### with buildpacks

bin/build

@@ -9,10 +9,14 @@ platform_dir=$2
 
 # shellcheck source=/dev/null
 source "$bp_dir/lib/build.sh"
+# shellcheck source=/dev/null
+source "$bp_dir/lib/utils/yarn.sh"
 rm -rf "$build_dir/node_modules"
 
+build_dir=$(extract_path_from_yarn_lock "$build_dir")
+
 export_env "$platform_dir/env" "" ""
 run_prebuild "$build_dir"
 install_or_reuse_node_modules "$build_dir" "$layers_dir/node_modules"
-run_build "$build_dir"
+run_build "$build_dir" "$layers_dir"
 write_launch_toml "$build_dir/package.json" "$layers_dir/launch.toml"

lib/build.sh

@@ -19,20 +19,24 @@ run_prebuild() {
   heroku_prebuild_script=$(json_get_key "$build_dir/package.json" ".scripts[\"heroku-prebuild\"]")
 
   if [[ $heroku_prebuild_script ]] ; then
+    cd $build_dir
     yarn heroku-prebuild
+    cd -
   fi
 }
 
 install_modules() {
   local build_dir=$1
 
+  cd $build_dir
   if detect_yarn_lock "$build_dir" ; then
-    echo "---> Installing node modules from ./yarn.lock"
+    echo "---> Installing node modules from $build_dir/yarn.lock"
     yarn install
   else
     echo "---> Installing node modules"
     yarn install --no-lockfile
   fi
+  cd -
 }
 
 install_or_reuse_node_modules() {
@@ -69,17 +73,43 @@ install_or_reuse_node_modules() {
 
 run_build() {
   local build_dir=$1
+  local layer_dir=$2
+  local build_cache
   local build_script
   local heroku_postbuild_script
 
+  build_cache=$(json_get_key "$build_dir/package.json" ".directories[\"heroku-buildcache\"]")
+  if [[ $build_cache ]] ; then
+    layer_dir="$layer_dir/$build_cache"
+    cat <<TOML > "$layer_dir.toml"
+cache = true
+build = false
+launch = false
+TOML
+    mkdir -p "${layer_dir}"
+    cp -r "$layer_dir" "$build_dir/$build_cache"
+    echo "$build_dir/$build_cache"
+    ls -lsa $build_dir/$build_cache
+  fi
+
   build_script=$(json_get_key "$build_dir/package.json" ".scripts.build")
   heroku_postbuild_script=$(json_get_key "$build_dir/package.json" ".scripts[\"heroku-postbuild\"]")
 
+  cd $build_dir
   if [[ $heroku_postbuild_script ]] ; then
     yarn heroku-postbuild
   elif [[ $build_script ]] ; then
     yarn build
   fi
+  cd -
+
+  echo "$build_dir/$build_cache"
+  ls -lsa $build_dir/$build_cache
+  ls -lsa $build_dir/resources/assets/build
+
+  if [[ $build_cache && -d "$build_dir/$build_cache" && -n "$(ls -A "$build_dir/$build_cache")" ]] ; then
+    cp -r "$build_dir/$build_cache/." "$layer_dir"
+  fi
 }
 
 write_launch_toml() {
@@ -93,5 +123,4 @@ type = "web"
 command = "yarn start"
 TOML
   fi
-
 }

lib/utils/yarn.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+extract_path_from_yarn_lock() {
+  local build_dir=$1
+
+  if grep -q -e "^# :yarn_path:" $build_dir/yarn.lock; then
+    echo "$1/$(cat $build_dir/yarn.lock | grep -s -e "^# :yarn_path:" | sed 's/^# :yarn_path:\(.*\)\s*$/\1/g')"
+  else
+    echo "$1"
+  fi
+}

package.toml

@@ -0,0 +1,5 @@
+[buildpack]
+uri = "."
+
+[[dependencies]]
+uri = "docker://public.ecr.aws/heroku-buildpacks/heroku-nodejs-engine-buildpack@sha256:4fa85f23b1df1138039ec6f5667da48da2af7858767b8840a754c54b39b42ca1"