decaffeinate: Rename CommandRunner.coffee and 25 other files from .coffee to .js

app/coffee/StaticServerForbidSymlinks.js

@@ -0,0 +1,41 @@
+Path = require("path")
+fs = require("fs")
+Settings = require("settings-sharelatex")
+logger = require("logger-sharelatex")
+url = require "url"
+
+module.exports = ForbidSymlinks = (staticFn, root, options) ->
+	expressStatic = staticFn root, options
+	basePath = Path.resolve(root)
+	return (req, res, next) ->
+		path = url.parse(req.url)?.pathname
+		# check that the path is of the form /project_id_or_name/path/to/file.log
+		if result = path.match(/^\/?([a-zA-Z0-9_-]+)\/(.*)/)
+			project_id = result[1]
+			file = result[2]
+		else
+			logger.warn path: path, "unrecognized file request"
+			return res.sendStatus(404)
+		# check that the file does not use a relative path
+		for dir in file.split('/')
+			if dir == '..'
+				logger.warn path: path, "attempt to use a relative path"
+				return res.sendStatus(404)
+		# check that the requested path is normalized
+		requestedFsPath = "#{basePath}/#{project_id}/#{file}"
+		if requestedFsPath != Path.normalize(requestedFsPath)
+				logger.error path: requestedFsPath, "requestedFsPath is not normalized"
+				return res.sendStatus(404)
+		# check that the requested path is not a symlink
+		fs.realpath requestedFsPath, (err, realFsPath)->
+			if err?
+				if err.code == 'ENOENT'
+					return res.sendStatus(404)
+				else
+					logger.error err:err, requestedFsPath:requestedFsPath, realFsPath:realFsPath, path: req.params[0], project_id: req.params.project_id, "error checking file access"
+					return res.sendStatus(500)
+			else if requestedFsPath != realFsPath
+				logger.warn requestedFsPath:requestedFsPath, realFsPath:realFsPath, path: req.params[0], project_id: req.params.project_id, "trying to access a different file (symlink), aborting"
+				return res.sendStatus(404)
+			else
+				expressStatic(req, res, next)