feat/refactor: Event-ID Generated for Notifications Only

+ Event-ID is generated in PREP notification middleware itself.
+ No longer setting `Event-ID` response header upon resource mutation, thus reverting the middlewares for unsafe methods to their original state, before PREP was introduced.

lib/handlers/delete.js

@@ -6,12 +6,9 @@ async function handler (req, res, next) {
   debug('DELETE -- Request on' + req.originalUrl)
 
   const ldp = req.app.locals.ldp
-  const prep = req.app.locals.prep
   try {
     await ldp.delete(req)
     debug('DELETE -- Ok.')
-    // Add event-id for notifications
-    prep && res.setHeader('Event-ID', res.setEventID())
     res.sendStatus(200)
     next()
   } catch (err) {

lib/handlers/notify.js

@@ -58,7 +58,7 @@ function handler (req, res, next) {
 
   const { method, path } = req
   const { statusCode } = res
-  const eventID = res.getHeader('event-id')
+  const eventID = res.setEventID()
   const fullUrl = new URL(path, `${req.protocol}://${req.hostname}/`)
 
   // Date is a hack since node does not seem to provide access to send date.

lib/handlers/patch.js

@@ -39,7 +39,6 @@ function contentForNew (contentType) {
 // Handles a PATCH request
 async function patchHandler (req, res, next) {
   debug(`PATCH -- ${req.originalUrl}`)
-  const prep = req.app.locals.prep
   try {
     // Obtain details of the target resource
     const ldp = req.app.locals.ldp
@@ -91,9 +90,6 @@ async function patchHandler (req, res, next) {
       await applyPatch(patchObject, graph, url)
       return writeGraph(graph, resource, ldp.resourceMapper.resolveFilePath(req.hostname), ldp.serverUri)
     })
-
-    // Add event-id for notifications
-    prep && res.setHeader('Event-ID', res.setEventID())
     // Send the status and result to the client
     res.status(resourceExists ? 200 : 201)
     res.send(result)

lib/handlers/post.js

@@ -11,7 +11,6 @@ const getContentType = require('../utils').getContentType
 
 async function handler (req, res, next) {
   const ldp = req.app.locals.ldp
-  const prep = req.app.locals.prep
   const contentType = getContentType(req.headers)
   debug('content-type is ', contentType)
   // Handle SPARQL(-update?) query
@@ -73,8 +72,6 @@ async function handler (req, res, next) {
     // Handled by backpressure of streams!
     busboy.on('finish', function () {
       debug('Done storing files')
-      // Add event-id for notifications
-      prep && res.setHeader('Event-ID', res.setEventID())
       res.sendStatus(200)
       next()
     })
@@ -94,8 +91,6 @@ async function handler (req, res, next) {
         debug('File stored in ' + resourcePath)
         header.addLinks(res, links)
         res.set('Location', resourcePath)
-        // Add event-id for notifications
-        prep && res.setHeader('Event-ID', res.setEventID())
         res.sendStatus(201)
         next()
       },

lib/handlers/put.js

@@ -59,7 +59,6 @@ async function checkPermission (request, resourceExists) {
 // TODO could be renamed as putResource (it now covers container and non-container)
 async function putStream (req, res, next, stream = req) {
   const ldp = req.app.locals.ldp
-  const prep = req.app.locals.prep
   // try {
   // Obtain details of the target resource
   let resourceExists = true
@@ -78,8 +77,6 @@ async function putStream (req, res, next, stream = req) {
     // Fails with Append on existing resource
     if (!req.originalUrl.endsWith('.acl')) await checkPermission(req, resourceExists)
     await ldp.put(req, stream, getContentType(req.headers))
-    // Add event-id for notifications
-    prep && res.setHeader('Event-ID', res.setEventID())
     res.sendStatus(resourceExists ? 204 : 201)
     return next()
   } catch (err) {