Function cspSafeGetterFn

test/angular/1.2/angular.js:11080–11191

* Implementation of the "Black Hole" variant from: * - http://jsperf.com/angularjs-parse-getter/4 * - http://jsperf.com/path-evaluation-simplified/7

(key0, key1, key2, key3, key4, fullExp, options)

 * - http://jsperf.com/path-evaluation-simplified/7
 */
function cspSafeGetterFn(key0, key1, key2, key3, key4, fullExp, options) {
  ensureSafeMemberName(key0, fullExp);
  ensureSafeMemberName(key1, fullExp);
  ensureSafeMemberName(key2, fullExp);
  ensureSafeMemberName(key3, fullExp);
  ensureSafeMemberName(key4, fullExp);
  var eso = function(o) {
    return ensureSafeObject(o, fullExp);
  };
  var expensiveChecks = options.expensiveChecks;
  var eso0 = (expensiveChecks || isPossiblyDangerousMemberName(key0)) ? eso : identity;
  var eso1 = (expensiveChecks || isPossiblyDangerousMemberName(key1)) ? eso : identity;
  var eso2 = (expensiveChecks || isPossiblyDangerousMemberName(key2)) ? eso : identity;
  var eso3 = (expensiveChecks || isPossiblyDangerousMemberName(key3)) ? eso : identity;
  var eso4 = (expensiveChecks || isPossiblyDangerousMemberName(key4)) ? eso : identity;

  return !options.unwrapPromises
      ? function cspSafeGetter(scope, locals) {
          var pathVal = (locals && locals.hasOwnProperty(key0)) ? locals : scope;

          if (pathVal == null) return pathVal;
          pathVal = eso0(pathVal[key0]);

          if (!key1) return pathVal;
          if (pathVal == null) return undefined;
          pathVal = eso1(pathVal[key1]);

          if (!key2) return pathVal;
          if (pathVal == null) return undefined;
          pathVal = eso2(pathVal[key2]);

          if (!key3) return pathVal;
          if (pathVal == null) return undefined;
          pathVal = eso3(pathVal[key3]);

          if (!key4) return pathVal;
          if (pathVal == null) return undefined;
          pathVal = eso4(pathVal[key4]);

          return pathVal;
        }
      : function cspSafePromiseEnabledGetter(scope, locals) {
          var pathVal = (locals && locals.hasOwnProperty(key0)) ? locals : scope,
              promise;

          if (pathVal == null) return pathVal;

          pathVal = eso0(pathVal[key0]);
          if (pathVal && pathVal.then) {
            promiseWarning(fullExp);
            if (!("$$v" in pathVal)) {
              promise = pathVal;
              promise.$$v = undefined;
              promise.then(function(val) { promise.$$v = eso0(val); });
            }
            pathVal = eso0(pathVal.$$v);
          }