bring caching logic to the forefront

bin/compile

@@ -1,74 +1,146 @@
 #!/usr/bin/env bash
+# bin/compile <build-dir> <cache-dir> <env-dir>
 
-####### Configure environment
+### Configure environment
 
 set -o errexit    # always exit on error
-set -o errtrace   # trap errors in functions as well
 set -o pipefail   # don't ignore exit codes when piping output
-set -o posix      # more strict failures in subshells
-# set -x          # enable debugging
-
-# Configure directories
-build_dir=$1
-cache_dir=$2
-env_dir=$3
-bp_dir=$(cd $(dirname $0); cd ..; pwd)
-heroku_dir=$build_dir/.heroku
-mkdir -p $heroku_dir/node
-warnings=$(mktemp)
-
-# Load dependencies
-source $bp_dir/lib/common.sh
-source $bp_dir/lib/build.sh
-source $bp_dir/lib/warnings.sh
-
-# Avoid GIT_DIR leak from previous build steps
-unset GIT_DIR
-
-# Provide hook to deal with errors
-trap build_failed ERR
-
-####### Determine current state
-
-head "Reading application state"
-read_current_state
-show_current_state
-
-if [ "$iojs_engine" == "" ]; then
-  warn_node_engine "$node_engine"
-else
-  warn_node_engine "$iojs_engine"
-fi
-warn_node_modules "$modules_source"
-
-####### Vendor in binaries
-
-head "Installing binaries"
-if [ "$iojs_engine" == "" ]; then
-  install_node "$node_engine"
-else
-  install_iojs "$iojs_engine"
-fi
-install_npm
-
-####### Build the project's dependencies
-
-head "Building dependencies"
-cd $build_dir
-build_dependencies
-
-####### Create a Procfile if possible
-
-head "Checking startup method"
-ensure_procfile "$start_method" "$build_dir"
-warn_start "$start_method"
-
-####### Finalize the build
-
-head "Finalizing build"
-write_profile
-write_export
-clean_npm
-clean_cache
-create_cache
-build_succeeded
+set -o nounset    # fail on unset variables
+unset GIT_DIR     # Avoid GIT_DIR leak from previous build steps
+
+### Configure directories
+
+BUILD_DIR=${1:-}
+CACHE_DIR=${2:-}
+ENV_DIR=${3:-}
+BP_DIR=$(cd $(dirname ${0:-}); cd ..; pwd)
+
+mkdir -p "$BUILD_DIR/.heroku/node/"
+cd $BUILD_DIR
+export PATH="$BUILD_DIR/.heroku/node/bin":$PATH
+
+### Load dependencies
+
+source $BP_DIR/lib/output.sh
+source $BP_DIR/lib/json.sh
+source $BP_DIR/lib/failure.sh
+source $BP_DIR/lib/environment.sh
+source $BP_DIR/lib/binaries.sh
+source $BP_DIR/lib/cache.sh
+source $BP_DIR/lib/dependencies.sh
+
+### Handle errors
+
+handle_failure() {
+  header "Build failed"
+  failure_message | indent
+}
+trap 'handle_failure' ERR
+
+### Check initial state
+
+[ -e "$BUILD_DIR/node_modules" ] && PREBUILD=true || PREBUILD=false
+
+### Failures that should be caught immediately
+
+fail_invalid_package_json "$BUILD_DIR"
+warn_prebuilt_modules "$BUILD_DIR"
+warn_missing_package_json "$BUILD_DIR"
+
+### Compile
+
+create_env() {
+  write_profile "$BP_DIR" "$BUILD_DIR"
+  write_export "$BP_DIR" "$BUILD_DIR"
+  export_env_dir "$ENV_DIR"
+  create_default_env
+}
+
+header "Creating runtime environment"
+create_env # can't indent the whole thing because piping causes subshells; no exporting possible
+list_node_config | indent
+
+install_bins() {
+  local node_engine=$(read_json "$BUILD_DIR/package.json" ".engines.node")
+  local iojs_engine=$(read_json "$BUILD_DIR/package.json" ".engines.iojs")
+  local npm_engine=$(read_json "$BUILD_DIR/package.json" ".engines.npm")
+
+  if [ -n "$iojs_engine" ]; then
+    echo "engines.iojs (package.json):  $iojs_engine (iojs)"
+  else
+    echo "engines.node (package.json):  ${node_engine:-unspecified}"
+  fi
+  echo "engines.npm (package.json):   ${npm_engine:-unspecified (use default)}"
+  echo ""
+
+  if [ -n "$iojs_engine" ]; then
+    warn_node_engine "$iojs_engine"
+    install_iojs "$iojs_engine" "$BUILD_DIR/.heroku/node"
+  else
+    warn_node_engine "$node_engine"
+    install_nodejs "$node_engine" "$BUILD_DIR/.heroku/node"
+  fi
+  install_npm "$npm_engine" "$BUILD_DIR/.heroku/node"
+  warn_old_npm
+}
+
+header "Installing binaries"
+install_bins | indent
+
+restore_cache() {
+  local cache_status=$(get_cache_status)
+
+  if [ "$cache_status" == "disabled" ]; then
+    echo "Skipping (cache disabled)"
+  elif [ "$cache_status" == "invalidated" ]; then
+    echo "Skipping (cache invalidated)"
+  else
+    local cache_directories=$(get_cache_directories)
+    if [ "$cache_directories" == "" ]; then
+      echo "Loading 1 from cacheDirectories (default):"
+      restore_cache_directories "$BUILD_DIR" "$CACHE_DIR" "node_modules"
+    else
+      echo "Loading $(echo $cache_directories | wc -w | xargs) from cacheDirectories (package.json):"
+      restore_cache_directories "$BUILD_DIR" "$CACHE_DIR" $cache_directories
+    fi
+  fi
+}
+
+header "Restoring cache"
+restore_cache | indent
+
+build_dependencies() {
+  if $PREBUILD; then
+    echo "Prebuild detected (node_modules already exists)"
+    rebuild_node_modules "$BUILD_DIR"
+  else
+    install_node_modules "$BUILD_DIR"
+  fi
+}
+
+header "Building dependencies"
+build_dependencies | indent
+
+cache_build() {
+  local cache_directories=$(get_cache_directories)
+  echo "Clearing previous node cache"
+  clear_cache
+  if [ "$cache_directories" == "" ]; then
+    echo "Saving 1 cacheDirectories (default):"
+    save_cache_directories "$BUILD_DIR" "$CACHE_DIR" "node_modules"
+  else
+    echo "Saving $(echo $cache_directories | wc -w | xargs) cacheDirectories (package.json):"
+    save_cache_directories "$BUILD_DIR" "$CACHE_DIR" $cache_directories
+  fi
+}
+
+header "Caching build"
+cache_build | indent
+
+summarize_build() {
+  cd $BUILD_DIR
+  (npm ls --depth=0 | tail -n +2 || true) 2>/dev/null
+}
+
+header "Build succeeded!"
+summarize_build | indent

bin/detect

@@ -2,9 +2,8 @@
 # bin/detect <build-dir>
 
 if [ -f $1/package.json ]; then
-  echo "Node.js" && exit 0
-elif [ -f $1/server.js ]; then
-  echo "Node.js" && exit 0
-else
-  echo "no" && exit 1
+  echo "Node.js"
+  exit 0
 fi
+
+exit 1

bin/release

@@ -1,6 +1,8 @@
 #!/usr/bin/env bash
 # bin/release <build-dir>
+
 cat << EOF
 addons: []
-default_process_types: {}
+default_process_types:
+  web: npm start
 EOF

lib/binaries.sh

@@ -0,0 +1,59 @@
+needs_resolution() {
+  local semver=$1
+  if ! [[ "$semver" =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
+    return 0
+  else
+    return 1
+  fi
+}
+
+install_nodejs() {
+  local version="$1"
+  local dir="$2"
+
+  if needs_resolution "$version"; then
+    echo "Resolving node version ${version:-(latest stable)} via semver.io..."
+    local version=$(curl --silent --get --data-urlencode "range=${version}" https://semver.herokuapp.com/node/resolve)
+  fi
+
+  echo "Downloading and installing node $version..."
+  local download_url="http://s3pository.heroku.com/node/v$version/node-v$version-$os-$cpu.tar.gz"
+  curl "$download_url" -s -o - | tar xzf - -C /tmp
+  mv /tmp/node-v$version-$os-$cpu/* $dir
+  chmod +x $dir/bin/*
+}
+
+install_iojs() {
+  local version="$1"
+  local dir="$2"
+
+  if needs_resolution "$version"; then
+    echo "Resolving iojs version ${version:-(latest stable)} via semver.io..."
+    version=$(curl --silent --get --data-urlencode "range=${version}" https://semver.herokuapp.com/iojs/resolve)
+  fi
+
+  echo "Downloading and installing iojs $version..."
+  local download_url="https://iojs.org/dist/v$version/iojs-v$version-$os-$cpu.tar.gz"
+  curl $download_url -s -o - | tar xzf - -C /tmp
+  mv /tmp/iojs-v$version-$os-$cpu/* $dir
+  chmod +x $dir/bin/*
+}
+
+install_npm() {
+  local version="$1"
+
+  if [ "$version" == "" ]; then
+    echo "Using default npm version: `npm --version`"
+  else
+    if needs_resolution "$version"; then
+      echo "Resolving npm version ${version} via semver.io..."
+      version=$(curl --silent --get --data-urlencode "range=${version}" https://semver.herokuapp.com/npm/resolve)
+    fi
+    if [[ `npm --version` == "$version" ]]; then
+      echo "npm `npm --version` already installed with node"
+    else
+      echo "Downloading and installing npm $version (replacing version `npm --version`)..."
+      npm install --unsafe-perm --quiet -g npm@$version 2>&1 >/dev/null
+    fi
+  fi
+}