Add variable argument `fetchPropsToMatch` to `json-prune` scriptlet

`fetchPropsToMatch` is an optional variable argument. If provided,
the scriplet will take effect only when the JSON data is obtained
through `Response.json()` and if there is a match with the value of
`fetchPropsToMatch` and the properties of the `Response` instance.

Examples of usage:

...##+js(json-prune, ads, , , fetchPropsToMatch, ?param=)
...##+js(json-prune, ads, , , fetchPropsToMatch, url:?param= method:get)

The optional variable argument `fetchPropsToMatch` acts as an additional
narrowing condition to fulfill before the JSON data is pruned.
This commit is contained in:
Raymond Hill 2023-08-08 10:18:34 -04:00
parent 8bf1ed954d
commit f8394ff2d5
No known key found for this signature in database
GPG Key ID: 25E1490B761470C2
1 changed files with 113 additions and 62 deletions

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@ -634,14 +634,14 @@ function objectPrune(
obj,
rawPrunePaths,
rawNeedlePaths,
stackNeedleDetails = { matchAll: true }
stackNeedleDetails = { matchAll: true },
extraArgs = {}
) {
if ( typeof rawPrunePaths !== 'string' ) { return obj; }
const prunePaths = rawPrunePaths !== ''
? rawPrunePaths.split(/ +/)
: [];
const safe = safeSelf();
const extraArgs = safe.getExtraArgs(Array.from(arguments), 4);
let needlePaths;
let log, reLogNeedle;
if ( prunePaths.length !== 0 ) {
@ -869,6 +869,67 @@ function matchesStackTrace(
return r;
}
/******************************************************************************/
builtinScriptlets.push({
name: 'parse-properties-to-match.fn',
fn: parsePropertiesToMatch,
dependencies: [
'safe-self.fn',
],
});
function parsePropertiesToMatch(propsToMatch, implicit = '') {
const safe = safeSelf();
const needles = new Map();
if ( propsToMatch === undefined || propsToMatch === '' ) { return needles; }
for ( const needle of propsToMatch.split(/\s+/) ) {
const [ prop, pattern ] = needle.split(':');
if ( prop === '' ) { continue; }
if ( pattern !== undefined ) {
needles.set(prop, { pattern, re: safe.patternToRegex(pattern) });
} else if ( implicit !== '' ) {
needles.set(implicit, { pattern: prop, re: safe.patternToRegex(prop) });
}
}
return needles;
}
/******************************************************************************/
builtinScriptlets.push({
name: 'match-object-properties.fn',
fn: matchObjectProperties,
});
function matchObjectProperties(propNeedles, ...objs) {
if ( matchObjectProperties.extractProperties === undefined ) {
matchObjectProperties.extractProperties = (src, des, props) => {
for ( const p of props ) {
const v = src[p];
if ( v === undefined ) { continue; }
des[p] = src[p];
}
};
}
const haystack = {};
const props = Array.from(propNeedles.keys());
for ( const obj of objs ) {
if ( obj instanceof Object === false ) { continue; }
matchObjectProperties.extractProperties(obj, haystack, props);
}
for ( const [ prop, details ] of propNeedles ) {
let value = haystack[prop];
if ( value === undefined ) { continue; }
if ( typeof value !== 'string' ) {
try { value = JSON.stringify(value); }
catch(ex) { }
}
if ( typeof value !== 'string' ) { continue; }
if ( details.re.test(value) ) { continue; }
return false;
}
return true;
}
/*******************************************************************************
Injectable scriptlets
@ -1125,8 +1186,11 @@ builtinScriptlets.push({
name: 'json-prune.js',
fn: jsonPrune,
dependencies: [
'match-object-properties.fn',
'object-prune.fn',
'parse-properties-to-match.fn',
'safe-self.fn',
'should-log.fn',
],
});
// When no "prune paths" argument is provided, the scriptlet is
@ -1142,29 +1206,45 @@ function jsonPrune(
) {
const safe = safeSelf();
const stackNeedleDetails = safe.initPattern(stackNeedle, { canNegate: true });
const extraArgs = Array.from(arguments).slice(3);
JSON.parse = new Proxy(JSON.parse, {
apply: function(target, thisArg, args) {
return objectPrune(
Reflect.apply(target, thisArg, args),
rawPrunePaths,
rawNeedlePaths,
stackNeedleDetails,
...extraArgs
);
},
});
Response.prototype.json = new Proxy(Response.prototype.json, {
apply: function(target, thisArg, args) {
return Reflect.apply(target, thisArg, args).then(o =>
objectPrune(
o,
const extraArgs = safe.getExtraArgs(Array.from(arguments), 3);
const logLevel = shouldLog(extraArgs);
const fetchPropNeedles = parsePropertiesToMatch(extraArgs.fetchPropsToMatch, 'url');
if ( fetchPropNeedles.size === 0 ) {
JSON.parse = new Proxy(JSON.parse, {
apply: function(target, thisArg, args) {
return objectPrune(
Reflect.apply(target, thisArg, args),
rawPrunePaths,
rawNeedlePaths,
stackNeedleDetails,
...extraArgs
)
);
extraArgs
);
},
});
}
Response.prototype.json = new Proxy(Response.prototype.json, {
apply: function(target, thisArg, args) {
const dataPromise = Reflect.apply(target, thisArg, args);
if ( fetchPropNeedles.size !== 0 ) {
const outcome = matchObjectProperties(fetchPropNeedles, thisArg)
? 'match'
: 'nomatch';
if ( outcome === logLevel || logLevel === 'all' ) {
safe.uboLog(
`json-prune (${outcome})`,
`\n\tpropsToMatch: ${JSON.stringify(Array.from(fetchPropNeedles)).slice(1,-1)}`,
'\n\tprops:', thisArg,
);
}
if ( outcome === 'nomatch' ) { return dataPromise; }
}
return dataPromise.then(data => objectPrune(
data,
rawPrunePaths,
rawNeedlePaths,
stackNeedleDetails,
extraArgs
));
},
});
}
@ -3316,6 +3396,8 @@ builtinScriptlets.push({
requiresTrust: true,
fn: trustedReplaceFetchResponse,
dependencies: [
'match-object-properties.fn',
'parse-properties-to-match.fn',
'safe-self.fn',
'should-log.fn',
],
@ -3333,22 +3415,7 @@ function trustedReplaceFetchResponse(
const log = logLevel ? ((...args) => { safe.uboLog(...args); }) : (( ) => { });
if ( pattern === '*' ) { pattern = '.*'; }
const rePattern = safe.patternToRegex(pattern);
const propNeedles = new Map();
for ( const needle of propsToMatch.split(/\s+/) ) {
const [ prop, value ] = needle.split(':');
if ( prop === '' ) { continue; }
if ( value === undefined ) {
propNeedles.set('url', prop);
} else {
propNeedles.set(prop, value);
}
}
const propReducer = (src, des, prop) => {
if ( src[prop] !== undefined ) {
des[prop] = src[prop];
}
return des;
};
const propNeedles = parsePropertiesToMatch(propsToMatch, 'url');
self.fetch = new Proxy(self.fetch, {
apply: function(target, thisArg, args) {
if ( logLevel === true ) {
@ -3358,51 +3425,35 @@ function trustedReplaceFetchResponse(
if ( pattern === '' ) { return fetchPromise; }
let outcome = 'match';
if ( propNeedles.size !== 0 ) {
const props = [
'cache', 'credentials', 'destination', 'method',
'mode', 'redirect', 'referrer', 'referrer-policy',
'url',
];
const normalArgs = args[0] instanceof Object
? props.reduce((a, p) => propReducer(args[0], a, p), {})
: { url: args[0] };
const objs = [ args[0] instanceof Object ? args[0] : { url: args[0] } ];
if ( args[1] instanceof Object ) {
props.reduce((a, p) => propReducer(args[0], a, p), normalArgs);
objs.push(args[1]);
}
for ( const prop of props ) {
let value = normalArgs[prop];
if ( value === undefined ) { continue; }
if ( typeof value !== 'string' ) {
try { value = JSON.stringify(value); }
catch(ex) { }
}
if ( typeof value !== 'string' ) { continue; }
const needle = propNeedles.get(prop);
if ( needle === undefined ) { continue; }
if ( safe.patternToRegex(needle).test(value) ) { continue; }
if ( matchObjectProperties(propNeedles, ...objs) === false ) {
outcome = 'nomatch';
break;
}
if ( outcome === logLevel || logLevel === 'all' ) {
log(
`trusted-replace-fetch-response (${outcome})`,
`\n\tpropsToMatch: ${JSON.stringify(Array.from(propNeedles)).slice(1,-1)}`,
`\n\tprops: ${JSON.stringify(normalArgs).slice(1,-1)}`,
'\n\tprops:', ...args,
);
}
}
if ( outcome === 'nomatch' ) { return fetchPromise; }
return fetchPromise.then(responseBefore => {
return responseBefore.text().then(textBefore => {
const response = responseBefore.clone();
return response.text().then(textBefore => {
const textAfter = textBefore.replace(rePattern, replacement);
const outcome = textAfter !== textBefore ? 'match' : 'nomatch';
if ( outcome === logLevel || logLevel === 'all' ) {
log(
`trusted-replace-fetch-response (${outcome})`,
`\n\tpattern: ${rePattern.source}`,
`\n\tpattern: ${pattern}`,
`\n\treplacement: ${replacement}`,
);
}
if ( outcome === 'nomatch' ) { return responseBefore; }
const responseAfter = new Response(textAfter, {
status: responseBefore.status,
statusText: responseBefore.statusText,