remove some comments, add some comments

bin/common.sh

@@ -8,13 +8,10 @@ set -e
 
 download_and_install_node() {
   version="$1"
-
-  status "Downloading node $version"
+  status "Downloading and installing node v$version"
   node_url="http://s3pository.heroku.com/node/v$version/node-v$version-linux-x64.tar.gz"
   curl $node_url -s -o - | tar xzf - -C $build_dir
   mv $build_dir/node-v$version-linux-x64 $build_dir/node
-
-  status "Adding node and npm to \$PATH"
   chmod +x $build_dir/node/bin/*
   PATH=$PATH:$build_dir/node/bin
 }
@@ -44,18 +41,15 @@ error() {
   exit 1
 }
 
-function status() {
+status() {
   echo "-----> $*"
 }
 
-function mktmpdir() {
-  dir=$(mktemp -t node-$1-XXXX)
-  rm -rf $dir
-  mkdir -p $dir
-  echo $dir
-}
 
-function indent() {
+# sed -l basically makes sed replace and buffer through stdin to stdout
+# so you get updates while the command runs and dont wait for the end
+# e.g. npm install | indent
+indent() {
   c='s/^/       /'
   case $(uname) in
     Darwin) sed -l "$c";;
@@ -64,7 +58,5 @@ function indent() {
 }
 
 function cat_npm_debug_log() {
-  if [ -f $BUILD_DIR/npm-debug.log ]; then
-    cat $BUILD_DIR/npm-debug.log
-  fi
+  [ -f $build_dir/npm-debug.log ] && cat $build_dir/npm-debug.log
 }

bin/compile

@@ -8,9 +8,10 @@ stable_version="0.10.18"
 source $bp_dir/bin/common.sh
 
 # Output debug info on exit
-# trap cat_npm_debug_log EXIT
+trap cat_npm_debug_log EXIT
 
-status "Downloading node version $stable_version"
+# Bootstrap the build process with latest stable version of node
+# We'll use it to parse package.json and do semver detection
 download_and_install_node $stable_version
 
 # Is a node version specified in package.json?
@@ -20,21 +21,21 @@ determine_requested_version() {
 }
 requested_version=$(determine_requested_version)
 
-# Give a warning if no node engine is specified
+# Give a warning if engines.node is unspecified
 if ! test $requested_version; then
   node_version=$stable_version
   echo
   echo "WARNING: No node version specified in package.json, see:" | indent
   echo "https://devcenter.heroku.com/articles/nodejs-support#versions" | indent
   echo
-  status "Using latest stable node version $stable_version"
+  status "Defaulting to node v$stable_version (latest stable)"
 
 else
   # Does the already-downloaded stable version of node satisfy the requested version?
   default_satisfies=$(node $bp_dir/vendor/semver/bin/semver -v "${stable_version}" -r "${requested_version}" || echo "")
 
   if test $default_satisfies; then
-    status "Using latest stable node version $stable_version"
+    status "Using node v$stable_version"
     node_version=$stable_version
   else
     # Find all available versions from nodejs.org/dist
@@ -50,7 +51,6 @@ else
     node_version=$(echo $evaluated_versions | tail -n 1)
 
     if test $node_version; then
-      status "Using node version $node_version"
       download_and_install_node $node_version
     else
       error "Requested node version ${requested_version} not found among available versions on nodejs.org/dist"