adding support for the target property.

lib/helpers/columnSet.js

@@ -546,6 +546,7 @@ function ColumnSet(columns, options) {
         const info = npm.utils.getIfHas(source, a.name);
         a.exists = !!info.has;
         if (a.exists) {
+            a.target = info.target; // TODO: target needs to be documented
             a.value = info.value;
         } else {
             a.value = 'def' in column ? column.def : undefined;

lib/utils/index.js

@@ -145,33 +145,40 @@ function InternalError(error) {
     this.error = error;
 }
 
-//////////////////////////////////////////////////////////////
+//////////////////////////////////////////////////////////////////////
 // Parses a property name, and gets its name from the object,
-// if the property exists. Returns object {valid, has, value}
+// if the property exists. Returns object {valid, has, target, value}:
+//  - valid - true/false, whether the syntax is valid
+//  - has - whether the property exists; it is set when 'valid' = true
+//  - target - the target object that contains the property, set when 'has' = true
+//  - value - the value; set when 'has' = true
 function getIfHas(obj, prop) {
     const result = {valid: true};
     if (prop.indexOf('.') === -1) {
         result.has = prop in obj;
+        result.target = obj;
         if (result.has) {
             result.value = obj[prop];
         }
     } else {
         const names = prop.split('.');
-        let missing;
+        let missing, target;
         for (let i = 0; i < names.length; i++) {
             const n = names[i];
             if (!n) {
                 result.valid = false;
                 return result;
             }
             if (!missing && obj && typeof obj === 'object' && n in obj) {
+                target = obj;
                 obj = obj[n];
             } else {
                 missing = true;
             }
         }
         result.has = !missing;
         if (result.has) {
+            result.target = target;
             result.value = obj;
         }
     }