split checkPrecondition so it can be used in cleaner as well

src/storage/s3.js

@@ -2,7 +2,8 @@
 
 exports = module.exports = {
     getBackupRootPath,
-    checkBackupPreconditions,
+    getBackupProviderStatus,
+    getAvailableSize,
 
     upload,
     exists,
@@ -31,7 +32,6 @@ const assert = require('assert'),
     AwsSdk = require('aws-sdk'),
     BoxError = require('../boxerror.js'),
     constants = require('../constants.js'),
-    DataLayout = require('../datalayout.js'),
     debug = require('debug')('box:storage/s3'),
     https = require('https'),
     path = require('path'),
@@ -98,9 +98,16 @@ function getBackupRootPath(apiConfig) {
     return apiConfig.prefix;
 }
 
-async function checkBackupPreconditions(apiConfig, dataLayout) {
+async function getBackupProviderStatus(apiConfig) {
     assert.strictEqual(typeof apiConfig, 'object');
-    assert(dataLayout instanceof DataLayout, 'dataLayout must be a DataLayout');
+
+    return { state: 'active' };
+}
+
+async function getAvailableSize(apiConfig) {
+    assert.strictEqual(typeof apiConfig, 'object');
+
+    return Number.POSITIVE_INFINITY;
 }
 
 function upload(apiConfig, backupFilePath, sourceStream, callback) {