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Controlling access to global variables via an ES6 proxy

The following function evalCode() traces the global variables that are accessed while evaluating a piece of JavaScript code.


Why does this work? [].concat[1,2,3]

In this blog post, we look at a syntactic puzzle. This is just for fun; there is nothing useful you can do with what we examine. It may, however, make you more aware of how JavaScript works, syntactically.


Pitfall: not all objects can be wrapped transparently by proxies

A proxy object can be seen as intercepting operations performed on its target object – the proxy wraps the target. The proxy’s handler object is like an observer or listener for the proxy. It specifies which operations should be intercepted by implementing corresponding methods (get for reading a property, etc.). If the handler method for an operation is missing then that operation is not intercepted. It is simply forwarded to the target.

Therefore, if the handler is the empty object, the proxy should transparently wrap the target. Alas, that doesn’t always work, as this blog post explains.


Computing tag functions for ES6 template literals

This blog post describes what you can do with functions that return tag functions for ES6 template literals.

For an introduction to template literals, tagged template literals and tag functions, consult chapter “Template literals” in “Exploring ES6”.