json-prune

The json-prune snippet traps calls to JSON.parse and, if the result is an Object, removes the specified properties from the result before returning to the caller.

It wraps both JSON.parse and Response.prototype.json, so a payload is covered whether the page parses it itself or reads it straight off a fetch response with await response.json().

Parameters

Name	Description	Mandatory
`rawPrunePaths`	Space-separated properties to remove. Accepts `{}` and `[]` placeholders to iterate over nested objects and arrays. Each entry can also be a `jsonpath(...)` query — see below.	Yes
`rawNeedlePaths`	Space-separated properties which must all be present for pruning to occur.	No
`rawNeedleStack`	Space-separated strings or regex which must be present in the call stack.	No

JSONPath mode

When an entry in rawPrunePaths starts with jsonpath(, the query is evaluated against the parsed object and every property it matches is deleted. Use it when the placeholder syntax cannot express the shape you need — for example filtering on a sibling property's value, or matching at an unknown depth with $... For simple fixed paths, the dotted and placeholder forms remain easier to read.

rawPrunePaths is split on spaces, so a query must not contain spaces.
Quotes inside a filter expression must be written \', or the parser strips them.
Entries are evaluated independently, so plain properties and queries can be mixed in one filter.
For the supported query syntax, see JSONPath evaluator. For the escaping rules, see Snippets Overview.

Filter examples

Filter	Result
`json-prune ads`	Removes any `ads` property from every object parsed with `JSON.parse`.
`json-prune 'ads videoAds'`	Removes all `ads` and `videoAds` properties.
`json-prune ads userId`	Removes `ads` from every object with a `userId` property.
`json-prune data.nested.[].ad`	Removes all `ad` properties listed inside an array.
`json-prune data.nested.{}.ad`	Removes all `ad` properties listed inside nested objects.
`json-prune data.nested.[-].elem.ad`	Removes array elements that have an `ad` property.
`json-prune data.nested.{-}.ad`	Removes object properties that contain the property `ad`.
`json-prune ads '' functionName`	Removes `ads` if `functionName` is found in the call stack.
`json-prune 'jsonpath($..ads)'`	JSONPath mode. Removes every `ads` property at any depth.
`json-prune 'jsonpath($.items[?(@.type==\'ad\')])'`	Removes every element of `items` whose `type` is `ad` — a condition on the data that the placeholder syntax cannot express.
`json-prune 'jsonpath($..ads) videoAds'`	Mixes forms: prunes via the query and via the plain `videoAds` property in the same filter.

Debugging

Message	When	Definition
`Wrapped JSON.parse for prune`	After wrapping	The API was wrapped.
`Wrapped Response.json for prune`	After wrapping	Payloads read via `await response.json()` are covered too.
`Found needle in stack trace: <<rawNeedleStack>>`	After comparing stack trace	The needle was found.
`Found <<rawPrunePaths>> and deleted.`	After deletion	A property was found and deleted.
`Invalid JSONPath query: <<path>>. Error: <<message>>`	Right after the snippet fires	The query could not be compiled, so that entry will never match.
`JSONPath match found and deleted at [<<key>>]`	Per matched property	A property matched the query and was deleted. One message per match.
`JSONPath evaluation failed for: <<path>>. Error: <<message>>`	Evaluating a compiled query threw	That object is left untouched.