chore: Improve the way a npm build script is found. (#150)

* chore: Improve the way a npm build script is found. * This commit will first install just the production-only dependencies. Then a script will check the package.json for a build script. If non is found, it just continues, but if there is a build script, `npm install` will be called again to install the dev dependencies. Then `npm run build` is execute. * This reason for doing this way was so we weren't installing all dependecies if we didn't need them * need to set the NODE_ENV to development to install dev deps when on in debug mode. * Also don't do npm install twice, since this could trigger postinstall scripts twice

Author: lholmquist

s2i/assemble

@@ -49,13 +49,25 @@ else
 if [ "$DEV_MODE" == true ]; then
 echo "---> Using 'npm install'"
 npm install
-else
-echo "---> Installing all dependencies"
-NODE_ENV=development npm install
 
 #do not fail when there is no build script
-echo "---> Building in production mode"
+echo "---> Building in development mode"
 npm run build --if-present
+else
+HAS_BUILD=$(node -e "console.log(require('./package.json').scripts.build ? true : false)")
+
+# check to see if there is a build script by inspecting the package.json
+if [ "$HAS_BUILD" == true ]; then
+# Do a npm install to get the dev depdencies
+echo "---> Installing dev dependencies"
+NODE_ENV=development npm install
+#do not fail when there is no build script
+echo "---> Building in production mode"
+npm run build --if-present
+else
+echo "---> Using 'npm install -s --only=production'"
+npm install -s --only=production
+fi
 
 echo "---> Pruning the development dependencies"
 npm prune