Function addInterceptor

test/angular/1.6/angular.js:16927–16970

(parsedExpression, interceptorFn)

    }

    function addInterceptor(parsedExpression, interceptorFn) {
      if (!interceptorFn) return parsedExpression;
      var watchDelegate = parsedExpression.$$watchDelegate;
      var useInputs = false;

      var regularWatch =
          watchDelegate !== oneTimeLiteralWatchDelegate &&
          watchDelegate !== oneTimeWatchDelegate;

      var fn = regularWatch ? function regularInterceptedExpression(scope, locals, assign, inputs) {
        var value = useInputs && inputs ? inputs[0] : parsedExpression(scope, locals, assign, inputs);
        return interceptorFn(value, scope, locals);
      } : function oneTimeInterceptedExpression(scope, locals, assign, inputs) {
        var value = parsedExpression(scope, locals, assign, inputs);
        var result = interceptorFn(value, scope, locals);
        // we only return the interceptor's result if the
        // initial value is defined (for bind-once)
        return isDefined(value) ? result : value;
      };

      // Propagate $$watchDelegates other then inputsWatchDelegate
      useInputs = !parsedExpression.inputs;
      if (watchDelegate && watchDelegate !== inputsWatchDelegate) {
        fn.$$watchDelegate = watchDelegate;
        fn.inputs = parsedExpression.inputs;
      } else if (!interceptorFn.$stateful) {
        // Treat interceptor like filters - assume non-stateful by default and use the inputsWatchDelegate
        fn.$$watchDelegate = inputsWatchDelegate;
        fn.inputs = parsedExpression.inputs ? parsedExpression.inputs : [parsedExpression];
      }

      if (fn.inputs) {
        fn.inputs = fn.inputs.map(function(e) {
              // Remove the isPure flag of inputs when it is not absolute because they are now wrapped in a
              // potentially non-pure interceptor function.
              if (e.isPure === PURITY_RELATIVE) {
                return function depurifier(s) { return e(s); };
              }
              return e;
            });
      }

      return fn;
    }
  }];
}