Improves documentation, add loading tests

Author: flovilmart

README.md

@@ -135,6 +135,20 @@ PARSE_SERVER_MAX_UPLOAD_SIZE
 
 ```
 
+##### Configuring S3 Adapter
+
+You can use the following environment variable setup the S3 adapter
+
+```js
+S3_ACCESS_KEY
+S3_SECRET_KEY
+S3_BUCKET
+S3_REGION
+S3_BUCKET_PREFIX
+S3_DIRECT_ACCESS
+
+```
+
 ## Contributing
 
 We really want Parse to be yours, to see it grow and thrive in the open source community. Please see the [Contributing to Parse Server guide](CONTRIBUTING.md).

spec/AdapterLoader.spec.js

@@ -1,6 +1,8 @@
 
 var loadAdapter = require("../src/Adapters/AdapterLoader").loadAdapter;
 var FilesAdapter = require("../src/Adapters/Files/FilesAdapter").default;
+var ParsePushAdapter = require("../src/Adapters/Push/ParsePushAdapter");
+var S3Adapter = require("../src/Adapters/Files/S3Adapter").default;
 
 describe("AdapterLoader", ()=>{
 
@@ -84,4 +86,27 @@ describe("AdapterLoader", ()=>{
     }).not.toThrow("foo is required for that adapter");
     done();
   });
+  
+  it("should load push adapter from options", (done) => {
+    var options = {
+      ios: {
+        bundleId: 'bundle.id'
+      }
+    }
+    expect(() => {
+      var adapter = loadAdapter(undefined, ParsePushAdapter, options);
+      expect(adapter.constructor).toBe(ParsePushAdapter);
+      expect(adapter).not.toBe(undefined);
+    }).not.toThrow();
+    done();
+  });
+  
+  it("should load S3Adapter from direct passing", (done) => {
+    var s3Adapter = new S3Adapter("key", "secret", "bucket")
+    expect(() => {
+      var adapter = loadAdapter(s3Adapter, FilesAdapter);
+      expect(adapter).toBe(s3Adapter);
+    }).not.toThrow();
+    done();
+  })
 });

src/Adapters/AdapterLoader.js

@@ -29,7 +29,7 @@ export function loadAdapter(adapter, defaultAdapter, options) {
   } else if (adapter.adapter) {
     return loadAdapter(adapter.adapter, undefined, adapter.options);
   }
-  // return the adapter as is as it's unusable otherwise
+  // return the adapter as provided
   return adapter;     
 }