Inherit content type from source in COPY handler

Author: rubensworks

lib/handlers/copy.js

@@ -22,17 +22,16 @@ async function handler (req, res, next) {
   const ldp = req.app.locals.ldp
   const serverRoot = ldp.resourceMapper.resolveUrl(req.hostname)
   const copyFromUrl = fromExternal ? copyFrom : serverRoot + copyFrom
-  const copyTo = res.locals.path || req.path
-  const { path: copyToPath } = await ldp.resourceMapper.mapUrlToFile({ url: req })
-  ldpCopy(copyToPath, copyFromUrl, function (err) {
-    if (err) {
-      let statusCode = err.statusCode || 500
-      let errorMessage = err.statusMessage || err.message
-      debug.handlers('Error with COPY request:' + errorMessage)
-      return next(error(statusCode, errorMessage))
-    }
-    res.set('Location', copyTo)
-    res.sendStatus(201)
-    next()
-  })
+  const copyToUrl = res.locals.path || req.path
+  try {
+    await ldpCopy(ldp.resourceMapper, copyToUrl, copyFromUrl)
+  } catch (err) {
+    let statusCode = err.statusCode || 500
+    let errorMessage = err.statusMessage || err.message
+    debug.handlers('Error with COPY request:' + errorMessage)
+    return next(error(statusCode, errorMessage))
+  }
+  res.set('Location', copyToUrl)
+  res.sendStatus(201)
+  next()
 }

lib/ldp-copy.js

@@ -3,6 +3,7 @@ module.exports = copy
 const debug = require('./debug')
 const fs = require('fs')
 const mkdirp = require('fs-extra').mkdirp
+const error = require('./http-error')
 const path = require('path')
 const http = require('http')
 const https = require('https')
@@ -21,47 +22,51 @@ function cleanupFileStream (stream) {
 
 /**
  * Performs an LDP Copy operation, imports a remote resource to a local path.
- * @param copyToPath {String} Local path to copy the resource into
+ * @param resourceMapper {ResourceMapper} A resource mapper instance.
+ * @param copyToUri {Object} The location (in the current domain) to copy to.
  * @param copyFromUri {String} Location of remote resource to copy from
- * @param callback {Function} Node error callback
+ * @return A promise resolving when the copy operation is finished
  */
-function copy (copyToPath, copyFromUri, callback) {
-  mkdirp(path.dirname(copyToPath), function (err) {
-    if (err) {
-      debug.handlers('COPY -- Error creating destination directory: ' + err)
-      return callback(
-        new Error('Failed to create the path to the destination resource: ' +
-          err))
-    }
-    const destinationStream = fs.createWriteStream(copyToPath)
-      .on('error', function (err) {
-        cleanupFileStream(this)
-        return callback(new Error('Error writing data: ' + err))
-      })
-      .on('finish', function () {
-        // Success
-        debug.handlers('COPY -- Wrote data to: ' + copyToPath)
-        callback()
-      })
+function copy (resourceMapper, copyToUri, copyFromUri) {
+  return new Promise((resolve, reject) => {
     const request = /^https:/.test(copyFromUri) ? https : http
     request.get(copyFromUri)
       .on('error', function (err) {
         debug.handlers('COPY -- Error requesting source file: ' + err)
         this.end()
-        cleanupFileStream(destinationStream)
-        return callback(new Error('Error writing data: ' + err))
+        return reject(new Error('Error writing data: ' + err))
       })
       .on('response', function (response) {
         if (response.statusCode !== 200) {
-          debug.handlers('COPY -- HTTP error reading source file: ' +
-            response.statusMessage)
+          debug.handlers('COPY -- HTTP error reading source file: ' + response.statusMessage)
           this.end()
-          cleanupFileStream(destinationStream)
           let error = new Error('Error reading source file: ' + response.statusMessage)
           error.statusCode = response.statusCode
-          return callback(error)
+          return reject(error)
         }
-        response.pipe(destinationStream)
+        // Grab the content type from the source
+        const contentType = response.headers['content-type']
+        resourceMapper.mapUrlToFile({ url: copyToUri, createIfNotExists: true, contentType })
+          .then(({ path: copyToPath }) => {
+            mkdirp(path.dirname(copyToPath), function (err) {
+              if (err) {
+                debug.handlers('COPY -- Error creating destination directory: ' + err)
+                return reject(new Error('Failed to create the path to the destination resource: ' + err))
+              }
+              const destinationStream = fs.createWriteStream(copyToPath)
+                .on('error', function (err) {
+                  cleanupFileStream(this)
+                  return reject(new Error('Error writing data: ' + err))
+                })
+                .on('finish', function () {
+                  // Success
+                  debug.handlers('COPY -- Wrote data to: ' + copyToPath)
+                  resolve()
+                })
+              response.pipe(destinationStream)
+            })
+          })
+          .catch(() => reject(error(500, 'Could not find target file to copy')))
       })
   })
 }