abort-on-property-write

The abort-on-property-write snippet patches a property on the window object that aborts execution when the property is written or set. No error gets printed to the console.

You can use this snippet to abort the execution of inline scripts.

Only use this snippet for written properties. Place it just inside the script you want to abort, otherwise, an error will be thrown.

Parameters

Name	Description	Mandatory
property	The name of the property or path to the property. If the property is a direct child of window, this parameter will be the property name. If you want to access a sub property, though, this parameter becomes a chain of properties separated by dots.	yes
setConfigurable	Value of the configurable attribute of the descriptor of property. If this parameter is not used it defaults to true. Setting it to false will prevent the property set and get being overwritten or otherwise changed by anybody. If this snippet doesn't work as expected when passing only the property, it could mean that the website is circumventing and setting this parameter to false can come in handy.	No

Filter examples

The following table lists examples that use the abort-on-property-write snippet:

Filter	Result
abort-on-property-write hasAdvert	The code that sets the hasAdvert global property throws an exception.
abort-on-property-write adHandler.cmd.push	The code that sets the push function throws an exception. This function is a property of cmd, which is a property of the adHandler global object.
abort-on-property-write Object.prototype.AdblockCookieMatchingType	The code that sets the AdblockCookieMatchingType property throws an exception. This example shows that you can attach the filter to prototype properties as well.

Debugging

The following table contains messages you'll find useful during debugging:

Message	When the error occurs	Definition
no property to abort on write	At the beginning of snippet execution	No property parameter was passed to the snippet.
setting <property> aborted	Each time the property is set, right before throwing the error	The error is about to be thrown.
aborting when setting <property>	Right before attaching to the property	This log is printed just before the snippet takes over the property getter OR setter.

Tradeoffs

Keep the following tradeoffs in mind when you use the abort-on-property-writefilter:

• The snippet is executed after all of a page's inline scripts. As a result, you should only attach properties read inside of a callback, which can be executed after the script.

• You can only attach this snippet to global properties, or properties of the window object.

• You should only attach to properties set just inside the script you want to abort. Otherwise, an error will be thrown.