Move Contentful access token logic to shared function so that service…

…s/contentful.coffee can use it. Trying to fix bug where no routes were generated when CONTENTFUL_PREVIEW=true.

config/concerns/cms.coffee

@@ -2,6 +2,7 @@
 Add configuration required to interact with CMS choice
 ###
 { join } = require 'path'
+{ getAccessToken } = require '../../services/contentful'
 module.exports = ({ cms }) ->
 	return unless cms
 
@@ -19,11 +20,7 @@ module.exports = ({ cms }) ->
 					CONTENTFUL_PREVIEW: process.env.CONTENTFUL_PREVIEW
 
 					# Don't expose the preview access token when it's not being used
-					CONTENTFUL_ACCESS_TOKEN: do ->
-						if process.env.CONTENTFUL_PREVIEW and
-							previewToken = process.env.CONTENTFUL_PREVIEW_ACCESS_TOKEN
-						then previewToken
-						else process.env.CONTENTFUL_ACCESS_TOKEN
+					CONTENTFUL_ACCESS_TOKEN: getAccessToken()
 
 		)
 	}

services/contentful.coffee

@@ -7,13 +7,19 @@ import axios from 'axios'
 # when services/contentful was imported from a Nuxt module
 nonEmpty = (array) -> array.filter (val) -> !!val
 
+export getAccessToken = ->
+	if process.env.CONTENTFUL_PREVIEW and
+		previewToken = process.env.CONTENTFUL_PREVIEW_ACCESS_TOKEN
+	then previewToken
+	else process.env.CONTENTFUL_ACCESS_TOKEN
+
 # Make a Contentful client
 client = axios.create
 	baseURL: 'https://graphql.contentful.com/content/v1/spaces/' +
 		process.env.CONTENTFUL_SPACE
 	headers:
 		'Content-Type': 'application/json'
-		'Authorization': 'Bearer ' + process.env.CONTENTFUL_ACCESS_TOKEN
+		'Authorization': 'Bearer ' + getAccessToken()
 
 # Retry requests when met with Contentful API rate limits.
 # https://www.contentful.com/developers/docs/references/graphql/#/introduction/api-rate-limits