[DEV-2506] StagingBucket: Add ability to prevent bypass

This is a kluge until time can be spent better factoring this
system (using Traits).

* src/bucket/StagingBucket.js (_noStagingBypass): Add field.
  (forbidBypass): Add method to set field.
  (setCommittedValues): Use field.

src/bucket/StagingBucket.js

@@ -80,6 +80,12 @@ module.exports = Class( 'StagingBucket' )
      */
     'private _dirty': false,
 
+    /**
+     * Prevent setCommittedValues from bypassing staging
+     * @type {boolean}
+     */
+    'private _noStagingBypass': false,
+
 
     /**
      * Initializes staging bucket with the provided data bucket
@@ -155,6 +161,11 @@ module.exports = Class( 'StagingBucket' )
      */
     'public setCommittedValues': function( data /*, ...*/ )
     {
+        if ( this._noStagingBypass )
+        {
+            return this.setValues.apply( this, arguments );
+        }
+
         this._bucket.setValues.apply( this._bucket, arguments );
 
         // no use in triggering a pre-update, since these values are
@@ -165,6 +176,20 @@ module.exports = Class( 'StagingBucket' )
     },
 
 
+    /**
+     * Prevent #setCommittedValues from bypassing staging
+     *
+     * When set, #setCommittedValues will act as an alias of #setValues.
+     *
+     * @return {StagingBucket} self
+     */
+    'public forbidBypass'()
+    {
+        this._noStagingBypass = true;
+        return this;
+    },
+
+
     /**
      * Determine whether values have changed
      *

test/bucket/StagingBucketTest.js

@@ -26,6 +26,7 @@
 const { Class } = require( 'easejs' );
 const root      = require( '../../' );
 const expect    = require( 'chai' ).expect;
+const sinon     = require( 'sinon' );
 
 const {
     Bucket,
@@ -161,6 +162,48 @@ describe( 'StagingBucket', () =>
             } );
         } );
     } );
+
+
+    describe( "#setCommittedValues", () =>
+    {
+        it( "bypasses staging bucket without no bypass flag", () =>
+        {
+            const b     = createStubBucket();
+            const bmock = sinon.mock( b );
+            const data  = { foo: [ "bar" ] };
+            const sut   = Sut( b );
+
+            bmock.expects( 'setValues' )
+                .once()
+                .withExactArgs( data );
+
+            sut.setCommittedValues( data );
+
+            // no diff if bypassed
+            expect( sut.getDiff() ).to.deep.equal( {} );
+
+            bmock.verify();
+        } );
+
+
+        it( "does not bypasses staging bucket with no bypass flag", () =>
+        {
+            const b     = createStubBucket();
+            const bmock = sinon.mock( b );
+            const data  = { foo: [ "bar" ] };
+            const sut   = Sut( b );
+
+            bmock.expects( 'setValues' ).never();
+
+            sut.forbidBypass();
+            sut.setCommittedValues( data );
+
+            // should have been staged
+            expect( sut.getDiff() ).to.deep.equal( data );
+
+            bmock.verify();
+        } );
+    } );
 } );