Added default value retrieval to pkgBuilder.getValue

This will assist in building generator prompts that return either
the existing value, or a sane default.

Change-Id: I66f47c70ebc529d0a1832677a925083c663adc8c

generators/app/lib/pkg_builder.js

@@ -47,16 +47,18 @@
   }
 
   /**
-   * Get a specific value from the package.json file.
+   * Get a specific value from the package.json file, or a default if the
+   * value is not set.
    *
    * @param {String} name The name of the value.
+   * @param {String} defaultValue A default value to return.
    * @returns {{}} A clone of the referenced value.
    */
-  function getValue (name) {
+  function getValue (name, defaultValue) {
     if (pkgContent.hasOwnProperty(name)) {
       return JSON.parse(JSON.stringify(pkgContent[name]));
     }
-    return undefined;
+    return defaultValue || undefined;
   }
 
   module.exports = {

spec/app/lib/pkg_builder.js

@@ -72,6 +72,13 @@
           builder.fromJSON('{"name":"foo"}');
           expect(builder.getValue('invalidname')).toBeUndefined();
         });
+
+      it('should return a default if provided.',
+        function () {
+          builder.fromJSON('{"name":"foo"}');
+          expect(builder.getValue('invalidname', 'defaultValue'))
+            .toBe('defaultValue');
+        });
     });
   });
 })();