This patch:
- stops appending `undefined` to our protocol messages unnecessarily.
- rewrites `Cannot find execution context id` to `Execution context was destroyed, most likely because of a navigation.` when it occurs from a Puppeteer ExecutionContext. The error message is left alone if it occurs via a CDPSession.
This patch eliminates a common race condition with WaitTask, that
happens when predicate function gets resolved right before the execution
context gets destroyed.
This situation results in a "Cannot find context with specified id undefined"
exception.
Credits go to @jakub300 for his wonderful [investigation](https://github.com/GoogleChrome/puppeteer/issues/1325#issuecomment-395472092).
Fixes#1325.
`Data.prototype.toString` may return non-ASCII characters, which aren't accepted by `setHeader`.
E.g., on Russian locale, it might look like this:
```
> new Date().toString()
'Thu Jun 14 2018 13:11:50 GMT+0300 (Финляндия (лето))'
```
This patch:
- adds `worker.evaluate` and `worker.evaluateHandle` methods as a shortcut to their execution context equivalents.
- makes the error messages a bit nicer when interacting with a closed worker (as opposed to a closed page).
- moves the worker tests into their own spec file.
This patch disables OOPIF by default.
**NOTE**: this is a temporary bandaid for the time we're crafting
the full-fledged support for site isolation over DevTools protocol.
References #2548.
It's impossible to launch chromium without initial page.
This patch makes sure that `puppeteer.launch()` always returns a browser
with at least one page user can connect to.
Since Node 10, `console.assert` no longer throws an AssertionError.
(This is generally good since it aligns Node.js with Browsers.)
This patch migrates all usages of `console.assert` in our codebase.
- All the `lib/` and testing code is migrated onto a handmade `assert`
function. This is to make Puppeteer transpilation / bundling easier.
- All the tooling is switched to use Node's `assert` module.
Fixes#2547.
Some of the worker tests were failing on the bots. After investigating, I found one race in the test, and one race upstream in Chromium which I filed upstream as https://crbug.com/846099. But I added a small hack here as a temporary workaround.
References #2632
This patch allows logging the output of the Chromium process to be enabled in tests by passing in the environment variable `DUMPIO=true`.
Additionally, the `stderr` of the Chromium process will always be logged in the the "Output" section of failing page tests.
Scrollbars look different on different platforms, so must be made invisible in tests. As a drive-by, xdescribe was broken with the new test runner.
References #2524
This adds `page.workers()`, and two events `workercreated` and `workerdestroyed`. It also forwards logs from a worker into the page `console` event.
Only dedicated workers are supported for now, ServiceWorkers will probably work differently because they aren't necessarily associated with a single page.
Fixes#2350.
This patch introduces Browser Contexts and methods to manage them:
- `browser.createIncognitoBrowserContext()` - to create new incognito
context
- `browser.browserContext()` - to get all existing contexts
- `browserContext.dispose()` - to dispose incognito context.
Fixes#85.
Today, `page.close()` method doesn't run page's beforeunload listeners.
This way users can be sure that `page.close()` actually closes the
page.
This patch adds an optional `runBeforeUnload` option to the
`page.close()` method that would run beforeunload listeners. Note:
running beforeunload handlers might cancel page closing.
Fixes#2386.
This patch teaches Page.waitForNavigation to correctly handle navigation
to pages that have frames that might never load.
These frames include:
- frames which main resource loading was aborted due to mixed-content
error
- frames that artificially called `window.stop()` to interrupt loading
themselves
Fixes#1936.
This patch fixes puppeteer navigation primitives to work with
same-document navigation.
Same-document navigation happens when document's URL is changed,
but document instance is not re-created. Some common scenarios
for same-document navigation are:
- History API
- anchor navigation
With this patch:
- pptr starts dispatching `framenavigated` event when frame's URL gets
changed due to same-document navigation
- `page.waitForNavigation` now works with same-document navigation
- `page.goBack()` and `page.goForward()` are handled correctly.
Fixes#257.
Today, we have tests split into multiple files, with files pulling
tests from some other files.
This patch starts explicitly gathering all tests from the same
`test.js` file.
Drive-By: move one test from `browser.spec.js` into `puppeteer.spec.js`
since it starts browser itself.
This roll includes:
- https://crrev.com/549003 - DevTools: make pptr tests pass with DCHECKs.
The patch fixes a browser crash that happens during browser close.
As a result, cookies were not saved properly (and thus the flaky test we
had).
Fixes#1537.
This roll includes:
- https://crrev.com/547982 - v8 roll that includes [fixed
Runtime.callFunctionOn](1637818671) method
The upstream fix makes it possible to run frame.waitFor* functions on
pages with strict CSP.
References #1229.
This patch introduces a new `pipe` option to the launcher to connect over a pipe.
In certain environments, exposing web socket for remote debugging is a security risk.
Pipe connection eliminates this risk.
This patch adds support for `timeout: 0` to disable timeout for the following functions:
- `page.waitForFunction`
- `page.waitForXPath`
- `page.waitForSelector`
and their `frame` counterparts.
Fixes#2200
This patch:
- starts fulfilling security details for redirect responses
- changes `response.securityDetails()` to return null if the response
is served over non-secure connection
This patch introduces ExecutionContext.frame() that returns Frame
associated with this Execution Context.
This allows to associate console messages with the originating frame,
if any.
This patch:
- introduces `SecurityDetails` class that exposes a set of fields that describe properties of secure connection
- introduces method `response.securityDetails()` that returns an instance of `SecurityDetails` object.
keyboard.down() and keyboard.up() both use the _pressedKeys Set, however keyboard.down() adds and searches for the key code, whereas keyboard.up() attempts to delete based on the key rather than the key code.
Fixes#1901
This patch introduces `BrowserFetcher` class that manages
downloaded versions of products.
This patch:
- shapes Downloader API to be minimal yet usable for our needs. This
includes removing such methods as `Downloader.supportedPlatforms` and
`Downloader.defaultRevision`.
- makes most of the fs-related methods in Downloader async. The only
exception is the `Downloader.revisionInfo`: it has stay sync due to the
`pptr.executablePath()` method being sync.
- updates `install.js` and `utils/check_availability.js` to use new API
- finally, renames `Downloader` into `BrowserFetcher`
Fixes#1748.
This patch:
- introduces `test/assets/cached` folder and teaches server to cache
all the assets from the folder
- introduces `test/assets/serviceworkers` folder that stores all the
service workers and makes them register with unique URL prefix
- introduces `Response.fromCache()` and `Response.fromServiceWorker()`
methods
Fixes#1551.
This PR fixes lost functionality that is no longer on-par with the documentation for `Page.select`, namely:
> `...values` <...string> Values of options to select. If the `<select>` has the `multiple` attribute, all values are considered, **otherwise only the first one is taken into account**.
I've also added an accompanying test for this use case.
This patch:
- introduces `page.waitForXPath` method
- introduces `frame.waitForXPath` method
- amends `page.waitFor` to treat strings that start with `//` as xpath queries.
Fixes#1757.
feat: expose raw devtools protocol connection
This patch introduces `target.createCDPSession` method that
allows directly communicating with the target over the
Chrome DevTools Protocol.
Fixes#31.
If the success value of `waitForFunction` was not serializable, checking whether it was truthy with `.jsonValue()` might fail. Now I check whether it was truthy inside the page.
Fixes#1737.
This patch:
- teaches page.waitFor* methods to accept JSHandles
- starts returning JSHandles from page.waitFor* calls.
BREAKING CHANGE: this patch starts allocating `JSHandle`/`ElementHandle` instances for every call to `page.waitFor*` functions. These handles should be disposed manually to avoid memory consumption.
Fixes#1703, fixes#1654, fixes#1724.
This patch adds two new methods to the `page.coverage` namespace:
- `page.coverage.startCSSCoverage()` - to initiate css coverage
- `page.coverage.stopCSSCoverage()` - to stop css coverage
The coverage format is consistent with the JavaScript coverage.
This patch introduces a new `page.coverage` namespace with two methods:
- `page.coverage.startJSCoverage` to initiate JavaScript coverage
recording
- `page.coverage.stopJSCoverage` to stop JavaScript coverage and get
results
This patch:
- adds `puppeteer.defaultArgs()` method to get default arguments that are used to launch chrome
- adds `ignoreDefaultArgs` option to `puppeteer.launch` to avoid using default puppeteer arguments
Fixes#872
The patch converts all the getters in the codebase into the methods.
For example, the `request.url` getter becomes the `request.url()`
method.
This is done in order to unify the API and make it more predictable.
The general rule for all further changes would be:
- there are no getters/fields exposed in the api
- the only exceptions are "namespaces", e.g. `page.keyboard`
Fixes#280.
BREAKING CHANGE:
This patch ditches getters and replaces them with methods throughout
the API. The following methods were added instead of the fields:
- dialog.type()
- consoleMessage.args()
- consoleMessage.text()
- consoleMessage.type()
- request.headers()
- request.method()
- request.postData()
- request.resourceType()
- request.url()
- response.headers()
- response.ok()
- response.status()
- response.url()
This patch migrates tests so that they can be run concurrently.
- By default, tests still run in one thread.
- To run tests in 4 parallel threads, run node test/test.js -j 4 or npm run unit -- -j 4
- Environment variable PPTR_PARALLEL_TESTS could be set to override default parallelization
Every test gets passed in a state. State is set up in the beforeAll and beforeEach callbacks,
and should be teared down in the afterAll and afterEach callbacks.
By default, state has a parallelIndex variable initialized that defines the thread index that runs the execution.
This patch unifies node6 transpilation:
- instead of generating multiple top-level directories, prefixed with
`node6-`, all transpiled code gets placed under single `node6/` folder
- transpilation doesn't change require paths of transpiled modules any
more
This patch:
- renames ChromiumDownloader into just Downloader (this is in
preparation for different products download)
- moves Downloader from utils/ to lib/. This unifies all of the
production-critical code in the lib/.
Drive-by: make Downloader a regular class.
This patch introduces a tiny test runner to run puppeteer tests.
The test runner is self-container and allows parallel (wrt IO) test execution.
It will also allow us to split tests into multiple files if necessary.
Comparing to the jasmine, the testrunner supports parallel execution, properly
handles "unhandled promise rejection" event and signals.
Comparing to ava/jest, the testrunner doesn't run multiple node processes,
which makes it simpler but sufficient for our goals.
When mojo is enabled for input events, we sometimes get an extra mouse move after the page is created. Moving the mouse ourselves makes the test consistent. The same behavior also caused DevTools dispatchMouseEvent to become flaky, but that will be fixed with: https://chromium-review.googlesource.com/c/chromium/src/+/804357
Since non-promise values always win the `Promise.race`, we shouldn't
return `null` for timeout promise in NavigationWatcher.
Instead, we can return a promise that never resolved. It should be
GC'd later with the navigation watcher itself.
Fixes#1417.
With the addition of `browser.targets()` api, we now can connect to
in-flight targets.
For Puppeteer, it means that it can "miss" certain events happenning
while it wasn't attached to the target.
This patch:
- fixes this problem with NetworkManager, preparing it for the
missed `requestWillBeSent` event.
- adds a new test to ensure that not a single unhandled promise
rejection has happened during test execution.
Fixes#1363.
In Blink, frames don't necesserily have execution context all the time.
DevTools Protocol precisely reports this situation, which results in
Puppeteer's frame.executionContext() being null occasionally.
However, from puppeteer point of view every frame will have at least a
default executions context, sooner or later:
- frame's execution context might be created naturally to run frame's
javascript
- if frame has no javascript, devtools protocol will issue execution
context creation
This patch builds up on this assumption and makes frame.executionContext()
to be a promise.
As a result, all the evaluations await for the execution context to be created first.
Fixes#827, #1325
BREAKING CHANGE: this patch changes frame.executionContext() method to return a promise.
To migrate onto a new behavior, await the context first before using it.
Currently, `elementHandle.screenshot` passes bounding box into the `page.captureScreenshot`
method.
This is wrong since `captureScreenshot` accepts viewport, not bounding box.
This patch uses layout metrics to convert bounding box into viewport.
Fixes#1315.
This patch:
- starts persisting lifecycle state for every frame
- migrates NavigationWatcher to rely on these lifecycle events
- refactors Page.goto to properly return navigation errors
Fixes#1218.
This patch starts asserting that all values are of type "string".
The alternative approach to cast values to strings
might yield a hard-to-debug errors.
Fixes#1276.
This patch migrates puppeteer to support PlzNavigate chromium
project.
As a consequence of this patch, we no longer wait for both
requestWillBeSent and requestIntercepted events to happen. This should
resolve a ton of request interception bugs that "hanged" the loading.
Fixes#877.
Currently, NavigationWatcher listens to lifecycle events from Page
domain and security events from Security domain.
However, the events are dispatched from different processes in browser:
- Page's lifecycle events are dispatched from renderer process
- Security events are dispatched from browser process
This makes for the undefined order between events and results in
NavigationWatcher reporting different failuer messages, based on
the event order.
This patch stops relying on security errors in navigation watcher and
instead switches to request failure codes for the main resource.
Fixes#1195
Elements in shadow dom erroneously considered that they were detached
from document.
This patch starts using `Element.isConnected` instead of
`document.contains()` call.
Fixes#1061.
This roll includes:
- crrev.com/510651 that changes request interception methods in protocol
- s/Page.setRequestInterceptionEnabled/Page.setRequestInterception
BREAKING CHANGE
Page.setRequestInterceptionEnabled is renamed into
Page.setRequestInterception.
This patch adds "options" parameter to the `page.setContent` method. The
parameter is the same as a navigation parameter and allows to specify
maximum timeout to wait for resources to be loaded, as well as to
describe events that should be emitted before the setContent operation
would be considered successful.
Fixes#728.
This patch adds support to multiple events that could be passed inside
navigation methods:
- Page.goto
- Page.waitForNavigation
- Page.goForward
- Page.goBack
- Page.reload
Fixes#805
This patch adds a new `domcontentloaded` option to a bunch of navigation
methods:
- Page.goto
- Page.waitForNavigation
- Page.goBack
- Page.goForward
- Page.reload
Fixes#946.
This patch:
- migrates navigation watcher to use protocol-issued lifecycle events.
- removes `networkIdleTimeout` and `networkIdleInflight` options for
`page.goto` method
- adds a new `networkidle0` value to the waitUntil option of navigation
methods
References #728.
BREAKING CHANGE:
As an implication of this new approach, the `networkIdleTimeout` and
`networkIdleInflight` options are no longer supported. Interested
clients should implement the behavior themselves using the `request` and
`response` events.
BREAKING CHANGE:
This patch lets key names be code in addition to key. When specifying a code, the proper text is generated assuming a standard US keyboard layout. e.g Digit5 -> "5" or "%" depending on Shift.
* location is now specified. #777
* Using unknown key names now throws an error. #723
* Typing newlines now correctly presses enter. #681
feat(interception): Implement request.respond method
This patch implements a new Request.respond method. This
allows users to fulfill the intercepted request with a hand-crafted
response if they wish so.
References #1020.
Currently, JSHandle.jsonValue() is implemented as in-page JSON.stringify
call and consequent JSON.parse in node. This approach proved to be
unfortunate for automation purposes: if page author overrode the
Object.prototype.toJSON method, then it's harder for puppeteer to
interact with the page.
This patch switches JSHandle.jsonValue to use protocol serialization
that ignores toJSON property. THis also changes the `page.evaluate`
behavior since it is based on JSHandle.jsonValue().
Fixes#1003.
BREAKING CHANGE:
`page.evaluate` no longer calls toJSON when generating return value.
For the old behavior, do JSON.parse/JSON.stringify manually:
```js
const json = JSON.parse(await page.evaluate(() => JSON.stringify(obj)));
```
This patch:
- introduces Target class that represents any inspectable target, such as service worker or page
- emits events when targets come and go
- introduces target.page() to instantiate a page from a target
Fixes#386, fixes#443.
Similarly to the `request.response()` method, this patch adds
`request.failure()` method that returns error details for the failed
requests.
Fixes#901.
This patch:
- changes `browser.close` to terminate browser.
- introduces new `browser.disconnect` to disconnect from a browser without closing it
This patch: fixes#918, fixes#989
BREAKING CHANGE:
`browser.close()` will always close a browser, even if it was initialized with
`puppeteer.connect`. To disconnect from a remote browser, use `browser.disconnect()` instead.
This patch starts generating input events for `keyboard.down`, addressing bullet 2 of
#723. With this patch, there's no longer any difference between `keboard.press('a')` and
`keyboard.press('a', {text: 'a'})`.
BREAKING CHANGE:
`keyboard.down('a')` starts generating input event (wasn't the case before).
References #723
This patch:
- deprecates injectFile as it was confused with the addScriptTag
- accepts an options object in addScriptTag which supports properties url, path and content.
- accepts an options object in addStyleTag which supports properties url, path and content.
Fixes#949.
BREAKING CHANGE:
- the addStyleTag/addScriptTag have changed;
- the injectFile was removed in favor of (addStyleTag({path:}).
This patch introduces `Page.queryObjects` and
`ExecutionContext.queryObjects` methods to query JavaScript heap
for objects with a certain prototype.
Fixes#304.
This patch improves life of puppeteer contributor on Windows:
- Setting environment variables using cross-env since Windows requires the SET command.
- Calling Jasmine in the script debug-unit using jasmine's JavaScript binary instead of shell.
- Add /test/test-user-data-dir* to .gitignore since temporary user data directories, in case of test
fails, remains in the test directory.
The page.plainText is confusing: it's unclear what kind of text it
returns, textContent or innerText. It's also easily polyfillable and
doesn't seem to be used.
BREAKING CHANGE: the page.plainText is not existing any more.
Instead, use `page.evaluate(() => document.body.innerText)`.
This patch:
- updates JSHandle.toString to make a nicer description for primitives
- excludes JSHandle.toString from documentation to avoid its abuse
References #382
This patch moves resourceType to be all small-caps. This aligns
with our convention that all string constants should be smallcaps.
BREAKING CHANGE: this patch changes the constants of the
request.resourceType to be all small-caps.
This patch:
- adds `ElementHandle.boundingBox()` method to get bounding box of element relative
to the page
- adds `ElementHandle.screenshot()` method to capture a screenshot of an element
This patch:
- adds input methods to ElementHandle, such as ElementHandle.type and ElementHandle.press
- changes `page.type` to accept selector as the first argument
- removes `page.press` method. The `page.press` is rarely used and doesn't operate with selectors; if there's a need to press a button, `page.keyboard.press` should be used.
BREAKING CHANGE: `page.type` is changed, `page.press` is removed.
Fixes#241.
This patch:
- introduces ExecutionContext class that incapsulates javascript
execution context. An examples of execution contexts are workers and
frames
- introduces JSHandle that holds a references to the javascript
object in ExecutionContext
- inherits ElementHandle from JSHandle
Fixes#382.
Headless isn't closing gracefully, which sometimes causes data loss when Chrome closes before it finishes writing things to disk.
See https://crbug.com/771830
References #921
This patch allows passing 0 to disable timeout for the following methods:
- page.goto
- page.waitForNavigation
- page.goForward
- page.goBack
Fixes#782.
This patch introduces ConsoleMessage type and starts dispatching
it for the 'console' event.
BREAKING CHANGE: this breaks the api of the 'console' event.
Fixes#744.
This lets the user pass `...args` into `page.waitFor`. It also clarifies that the docs that `options` is not optional if `...args` are specified.
Fixes#770
Since protocol ignores all HTTP headers that don't have string
value, this patch starts validating header key-values before
sending them over the protocol.
Fixes#713.
This patch:
- makes `browser.close()` return a promise that resolves when browser gets closed
- starts closing chrome gracefully if a custom `userDataDir` is supplied
Fixes#527
This patch:
- teaches `page.evaluate` to accept ElementHandles as parameters
- removes `ElementHandle.evaluate` method since it's not needed any
more
References #382
It turns out that [undefined, 1].join(',') results in ",1" instead
of "undefined,1". This causes a syntax error when trying to pass undefined
as a first argument to `page.evaluate` method.
Fixes#572.
Currently, navigation watcher throws exception if timeout
is exceeded.
Due to the way it is used in `page.navigate`, the promise
get's rejected before it is awaited, which is considered to
be "unhandled promise rejection".
Fixes#738
It's very bad to have 'unhandled promise rejection' that can't be
handled in user code. These errors will exit node process in a near
future.
This patch avoids 'unhandled promise rejection' while sending protocol
messages.
This patch:
- introduces `puppeteer:error` debug scope and starts using it for all
swalloed errors.
- makes sure that every `client.send` method is either awaited or its
errors are handled.
- starts return promises from Request.continue() and Request.abort().
- starts swallow errors from Request.contine() and Request.abort().
The last is the most important part of the patch. Since
`Request.continue()` might try to continue canceled request, we should
disregard the error.
Fixes#627.
This patch:
- adds `page.touchscreen` namespace, similar to `page.mouse` and `page.keyboard`.
- adds tapping to multiple layers:
- `page.touchscreen.tap`
- `page.tap` - convenience method which accepts selector
- `elementHandle.tap`
Fixes#568 and #569.
This patch:
- switches to objects instead of maps for headers (in Request, Response and
page.setExtraHTTPHeaders)
- converts all header names to lower case
Fixes#547, fixes#509
It turned out that either Network.requestIntercepted or
Network.requestWillBeSent occasionally report encoded URL.
This patch starts decoding URL's when generating request hash.
Fixes#558.
This patch:
- introduces a transpiler which substitutes async/await logic with
generators.
- starts using the transpiler to generate a node6-compatible version of puppeteer
- introduces a runtime-check to decide which version of code to use
Fixes#316.
This patch rolls chromium to r496140. This includes the r496130 that
introduces multiple sessions for single target.
With this patch, it is possible to run puppeteer in headful mode
and open devtools over the automated pages without puppeteer losing
connection to the page.
Fail gracefully when chromium failed to download
This patch changes both install.js and Launcher.js to inform how
chromium could be downloaded manually.
This patch:
- removes the `page.uploadFile` method
- adds `elementHandle.uploadFile` method.
Motivation: `elementHandle.uploadFile` is rarely used, so it doesn't worth it
to keep it on page.
This patch:
- rolls chromium to r494365
- starts using Runtime.evaluate(awaitPromise: true), with new semantic
we can avoid additional Runtime.awaitPromise call
- stops resolving promises for Console event
This patch:
- refactors Connection to use a single remote debugging URL instead of a
pair of port and browserTargetId
- introduces Puppeteer.connect() method to attach to already running
browser instance.
Fixes#238.
This patch:
- teaches request interception to ignore data URLs. Currently protocol
doesn't send interceptions for data URLs.
- teaches request interception to properly process URLs with hashes.
Currently `Network.requestIntercepted` sends url with a hash, whereas
`Network.requestWillBeSent` doesn't report hashes in its urls. @see
crbug.com/755456
- skips one more header that I spotted during debugging interception on
the realworld websites.
Fixes#258, #259.
This patch starts emitting 'error' event when page crashes.
'error' events have special treatment in node, so page crashes
become observable for users.
Fixes#262.
This patch:
- split browser launching logic from Browser into `lib/Launcher.js`
- introduce `puppeteer` namespace which currently has a single `launch`
method to start a browser
With this patch, the browser is no longer created with the `new
Browser(..)` command. Instead, it should be "launched" via the
`puppeteer.launch` method:
```js
const puppeteer = require('puppeteer');
puppeteer.launch().then(async browser => {
...
});
```
With this approach browser instance lifetime matches the lifetime of
actual browser process. This helps us:
- remove proxy streams, e.g. browser.stderr and browser.stdout
- cleanup browser class and make it possible to connect to remote
browser
- introduce events on the browser instance, e.g. 'page' event. In case
of lazy-launching browser, we should've launch browser when an event
listener is added, which is unneded comlpexity.
Mouse events are no longer racy. Enabling touch no longer converts all mouse events into touches. Promises in destroyed execution contexts are rejected immediately.
The issue #168 is a protocol inconsistency which happens only
in case of HTTPS error. This patch starts refering to the
upstream bug instead of puppeteer issue.
Closes#168.
This patch
- rolls chromium to 492629
- migrates connection establishing to use browser target. This migration means
that now we have a single websocket connection to browser (implemented
in Connection class). A connection to a particular target is
incapsulated in a new Session class.
This patch:
- changes interception API so that it better aligns with what we'd like to see
in #121
- fixes the issue with redirect interception
Fixes#217.
This patch starts using "Failed" command for request interception instead of
"Aborted".
The "Aborted" status also has a side-effect of cancelling the navigation, so
there will be no error on the page and form puppeteer's standpoint, the navigation
will never complete.
The chrome-devtools://devtools/bundled/inspector.html is a perfectly
valid url in headful chromium, so we should pick another one for test
to work (and for the navigation inside the test to fail).
This patch implements 'autoRepeat' functionality for `keyboard.down`.
With this patch, the subsequent calls to `keyboard.down` would generate
an event with 'autoRepeat` flag set to true.
Closes#157
This patch makes sure that request.text() doesn't try
to fetch response body from the backend until the request is
actually finished (finished or failed).
It turns out we're not receiving 'Network.requestWillBeSent' event
for every requestId.
This patch makes sure we don't dispatch `requestfinished` and
`requestfailed` events without passing actual request.
References #168
