[DEV-4338] Change behavior of default data

Default data was converted to an empty array if the data evaluated to
false. We only want to convert it if it is undefined so values that are
false remain false.

src/server/request/DataProcessor.js

@@ -297,7 +297,19 @@ module.exports = Class( 'DataProcessor',
                 const bdata = ( diff_data[ bucketid ] || [] )[ index ] ||
                       ( bucket.getDataByName( bucketid ) || [] )[ index ];
 
-                result[ srcid ] = bdata || [];
+                if ( typeof bdata === 'undefined' )
+                {
+                    // This might be better as an empty string, but we will
+                    // need to look into it more before we change it. It has
+                    // been an empty array for a long time and it might cause
+                    // issues to change it now.
+                    result[ srcid ] = [];
+                }
+                else
+                {
+                    result[ srcid ] = bdata;
+                }
+
                 return result;
             },
             {}

test/server/request/DataProcessorTest.js

@@ -107,7 +107,7 @@ describe( 'DataProcessor', () =>
             expect( given_request ).to.equal( request );
 
             done();
-        }
+        };
 
         Sut( filter, dapi_factory, null, createStubStagingBucket )
             .processDiff( {}, request, program );
@@ -250,6 +250,69 @@ describe( 'DataProcessor', () =>
 
         return Promise.all( dapis );
     } );
+
+
+    it( "check _mapDapiData default values", () =>
+    {
+        const triggered = {};
+
+        // g prefix = "given"
+        const getFieldData = function( gfield, gindex, gdapim, gdapi, gdata)
+        {
+            triggered[ gdapi.name ]           = triggered[ gdapi.name ] || [];
+            triggered[ gdapi.name ][ gindex ] = arguments;
+
+            expect( gdata ).to.deep.equal( { ina: '', inb: [] } );
+
+            return Promise.resolve( true );
+        };
+
+        const dapi_manager = {};
+
+        const {
+            request,
+            program,
+            filter,
+            meta_source,
+        } = createStubs( false, {}, getFieldData );
+
+        const sut = Sut(
+            filter,
+            () => dapi_manager,
+            meta_source,
+            createStubStagingBucket
+        );
+
+        program.meta.fields = {
+            foo: {
+                dapi: {
+                    name:   'dapi_foo',
+                    mapsrc: { ina: 'src', inb: 'src1' },
+                },
+            },
+        };
+
+        program.mapis = {
+            src1: [ 'foo' ],          // change
+        };
+
+        // data changed
+        const data = {
+            src:  [ 'src0', '' ],
+            src1: [ undefined, '' ],
+        };
+
+        const bucket = createStubBucket( {
+            src:  [ 'bsrc0', '' ],
+            src1: [ 'bsrc10', undefined],
+        } );
+
+        const { dapis } = sut.processDiff(
+            data, request, program, bucket
+        );
+
+        return Promise.all( dapis );
+    } );
 } );