// ==UserScript==
// @name Twitter Direct
// @description Remove t.co tracking links from Twitter
// @author chocolateboy
// @copyright chocolateboy
// @version 0.1.3
// @namespace https://github.com/chocolateboy/userscripts
// @license GPL: https://www.gnu.org/copyleft/gpl.html
// @include https://twitter.com/
// @include https://twitter.com/*
// @include https://mobile.twitter.com/
// @include https://mobile.twitter.com/*
// @run-at document-start
// @inject-into auto
// ==/UserScript==
/*
* the domain we expect metadata (JSON) to come from. if responses come from
* this domain, we strip it before passing the document's URI to the transformer.
*/
const TWITTER_API = 'api.twitter.com'
/*
* default locations to search for URL metadata (arrays of objects) within tweet
* nodes
*/
const TWEET_PATHS = [
'entities.media',
'entities.urls',
'extended_entities.media',
'extended_entities.urls',
]
/*
* default locations to search for URL metadata (arrays of objects) within
* user/profile nodes
*/
const USER_PATHS = [
'entities.description.urls',
'entities.url.urls',
]
/*
* paths into the JSON data in which we can find context objects, i.e. objects
* which have an `entities` (and/or `extended_entities`) property which contains
* URL metadata
*/
const SCHEMAS = [
{
match: /\/users\/lookup\.json$/,
root: [], // returns self
},
{
match: /\/Following$/,
root: 'data.user.following_timeline.timeline.instructions.*.entries.*.content.itemContent.user.legacy',
},
{
match: /\/Followers$/,
root: 'data.user.followers_timeline.timeline.instructions.*.entries.*.content.itemContent.user.legacy',
},
{
// found in /graphql/<query-id>/UserByScreenName
// used for hovercard data
root: 'data.user.legacy',
collect: Array.of,
},
{
root: 'globalObjects.tweets',
paths: TWEET_PATHS
},
{
// spotted in list.json and all.json (used for hovercard data).
// may exist in other documents
root: 'globalObjects.tweets.*.card.users.*'
},
{
root: 'globalObjects.users'
},
]
/*
* a pattern which matches the content-type header of responses we scan for
* tweets: "application/json" or "application/json; charset=utf-8"
*/
const CONTENT_TYPE = /^application\/json\b/
/*
* compatibility shim needed for Violentmonkey:
* https://github.com/violentmonkey/violentmonkey/issues/997#issuecomment-637700732
*/
const Compat = { unsafeWindow }
/*
* a function which takes an object and a path into that object (a string of
* dot-separated property names or an array of property names) and returns the
* value at that position within the object, or the (optional) default value if
* it can't be reached.
*
* based on just-safe-get by Angus Croll [1] (which in turn is an implementation
* of Lodash's function of the same name), but with added support for
* wildcard props, e.g.:
*
* foo.*.bar.baz.*.quux
*
* is roughly equivalent to:
*
* obj.foo
* |> Object.values(#)
* |> #.flatMap(value => get(value, "bar.baz", []))
* |> Object.values(#)
* |> #.flatMap(value => get(value, "quux", []))
*
* [1] https://www.npmjs.com/package/just-safe-get
*/
const get = (function () {
const emptyArray = []
// TODO release as an NPM module (just-safe-get is ES5 only, but this
// requires ES6 for Array#flatMap and Object.values, though both could be
// polyfilled
return function get (obj, path, $default) {
if (!obj) {
return $default
}
let props, prop
if (Array.isArray(path)) {
props = Array.from(path) // clone
} else if (typeof path === 'string') {
props = path.split('.')
} else {
throw new Error('path must be an array or string')
}
while (props.length) {
if (!obj) {
return $default
}
prop = props.shift()
if (prop === '*') {
// Object.values is very forgiving and works with anything that
// can be turned into an object via Object(...), i.e. everything
// but undefined and null, which we've guarded against above.
return Object.values(obj).flatMap(value => {
return get(value, Array.from(props), emptyArray)
})
}
obj = obj[prop]
if (obj === undefined) {
return $default
}
}
return obj
}
})()
/*
* replace t.co URLs with the original URL in all locations within the document
* which contain URL data
*/
function transformLinks (data, uri) {
const seen = new Map()
for (const schema of SCHEMAS) {
const want = schema.match
if (want) {
const match = (typeof want === 'string') ? uri === want : want.test(uri)
if (!match) {
continue
}
}
const root = get(data, schema.root)
if (!(root && (typeof root === 'object'))) { // may be an array (e.g. lookup.json)
continue
}
const { collect = Object.values, paths = USER_PATHS } = schema
const contexts = collect(root)
for (const context of contexts) {
for (const path of paths) {
const items = get(context, path, [])
for (const item of items) {
item.url = item.expanded_url
const oldCount = seen.get(schema.root) || 0
seen.set(schema.root, oldCount + 1)
}
}
}
}
if (seen.size) {
// format: "expanded 1 URL in "a.b" and 2 URLs in "c.d" in /2/example.json"
const stats = Array.from(seen).map(([path, count]) => {
const quantity = count === 1 ? '1 URL' : `${count} URLs`
return `${quantity} in ${JSON.stringify(path)}`
}).join(' and ')
console.debug(`expanded ${stats} in ${uri}`)
}
return data
}
/*
* parse and transform the JSON response, handling (catching and logging) any
* errors
*/
function transformResponse (json, path) {
let parsed
try {
parsed = JSON.parse(json)
} catch (e) {
console.error("Can't parse response:", e)
return
}
let transformed
try {
transformed = transformLinks(parsed, path)
} catch (e) {
console.error('error transforming JSON:', e)
return
}
return transformed
}
/*
* replacement for Twitter's default response handler. we transform the response
* if it's a) JSON and b) contains tweet data; otherwise, we leave it unchanged
*/
function onReadyStateChange (xhr, url) {
const contentType = xhr.getResponseHeader('Content-Type')
if (!CONTENT_TYPE.test(contentType)) {
return
}
const parsed = new URL(url)
const path = parsed.hostname === TWITTER_API ? parsed.pathname : parsed.origin + parsed.pathname
const transformed = transformResponse(xhr.responseText, path)
if (transformed) {
const descriptor = { value: JSON.stringify(transformed) }
const clone = Compat.cloneInto(descriptor, Compat.unsafeWindow)
Compat.unsafeWindow.Object.defineProperty(xhr, 'responseText', clone)
}
}
/*
* replace the built-in XHR#send method with our custom version which swaps in
* our custom response handler. once done, we delegate to the original handler
* (this.onreadystatechange)
*/
function hookXHRSend (oldSend) {
return function send () {
const oldOnReadyStateChange = this.onreadystatechange
this.onreadystatechange = function () {
if (this.readyState === this.DONE && this.responseURL && this.status === 200) {
onReadyStateChange(this, this.responseURL)
}
oldOnReadyStateChange.apply(this, arguments)
}
return oldSend.apply(this, arguments)
}
}
/*
* set up a cross-engine API to shield us from differences between engines so we
* don't have to clutter the code with conditionals.
*
* XXX the functions are only needed by Violentmonkey for Firefox, and are
* no-ops in other engines
*/
if ((typeof cloneInto === 'function') && (typeof exportFunction === 'function')) {
// Greasemonkey 4 (Firefox) and Violentmonkey (Firefox + Chrome)
Object.assign(Compat, { cloneInto, exportFunction })
// Violentmonkey for Firefox
if (unsafeWindow.wrappedJSObject) {
Compat.unsafeWindow = unsafeWindow.wrappedJSObject
}
} else {
Compat.cloneInto = Compat.exportFunction = value => value
}
/*
* replace the default XHR#send with our custom version, which scans responses
* for tweets and expands their URLs
*/
console.debug('hooking XHR#send:', Compat.unsafeWindow.XMLHttpRequest.prototype.send)
Compat.unsafeWindow.XMLHttpRequest.prototype.send = Compat.exportFunction(
hookXHRSend(window.XMLHttpRequest.prototype.send),
Compat.unsafeWindow
)