README.md

Zombie.js

The Bite

If you're going to write an insanely fast, headless browser, how can you not call it Zombie? Zombie it is.

Zombie.js is a lightweight framework for testing client-side JavaScript code in a simulated environment. No browser required.

Let's try to sign up to a page and see what happens:

var Browser = require("zombie");
var assert = require("assert");

// Load the page from localhost
browser = Browser.create()
browser.visit("http://localhost:3000/", function (error) {

  // Fill email, password and submit form
  browser.
    fill("email", "zombie@underworld.dead").
    fill("password", "eat-the-living").
    pressButton("Sign Me Up!", function() {

      // Form submitted, new page loaded.
      browser.assert.success();
      browser.assert.text("title", "Welcome To Brains Depot");

    });

});

Well, that was easy.

Installing

To install Zombie.js you will need Node.js 0.8 or later, NPM, a C++ toolchain and Python.

One-click installers for Windows, OS X, Linux and SunOS are available directly from the Node.js site.

On OS X you can download the full XCode from the Apple Store, or install the OSX GCC toolchain directly (smaller download).

You can also install Node and NPM using the wonderful Homebrew (if you're serious about developing on the Mac, you should be using Homebrew):

$ brew install node
$ node --version
v0.8.16
$ npm --version
1.1.69
$ npm install zombie

On Windows you will need to install a recent version of Python and Visual Studio. See node-gyp for specific installation instructions and Chocolatey for easy package management.

Browser

browser.assert

Methods for making assertions against the browser, such as browser.assert.element(".foo").

See Assertions for detailed discussion.

browser.console

Provides access to the browser console (same as window.console).

browser.referer

You can use this to set the HTTP Referer header.

browser.resources

Access to history of retrieved resources. Also provides methods for retrieving resources and managing the resource pipeline. When things are not going your way, try calling browser.resources.dump().

See Resources for detailed discussion.

browser.tabs

Array of all open tabs (windows). Allows you to operate on more than one open window at a time.

See Tabs for detailed discussion.

browser.eventLoop

browser.errors

Extending The Browser

Browser.extend(function(browser) {
  browser.on("console", function(level, message) {
    logger.log(message);
  });
  browser.on("log", function(level, message) {
    logger.log(message);
  });
});

Cookies

Are delicious. Also, somewhat tricky to work with. A browser will only send a cookie to the server if it matches the request domain and path.

Most modern Web applications don't care so much about the path and set all cookies to the root path of the application (/), but do pay attention to the domain.

Consider this code:

browser.setCookie(name: "session", domain: "example.com", value: "delicious");
browser.visit("http://example.com", function() {
  var value = browser.getCookie("session");
  console.log("Cookie", value);
});

In order for the cookie to be set in this example, we need to specify the cookie name, domain and path. In this example we omit the path and choose the default /.

To get the cookie in this example, we only need the cookie name, because at that point the browser has an open document, and it can use the domain of that document to find the right cookie. We do need to specify a domain if we're interested in other cookies, e.g for a 3rd party widget.

There may be multiple cookies that match the same host, for example, cookies set for .example.com and www.example.com will both match www.example.com, but only the former will match example.com. Likewise, cookies set for / and /foo will both match a request for /foo/bar.

getCookie, setCookie and deleteCookie always operate on a single cookie, and they match the most specific one, starting with the cookies that have the longest matching domain, followed by the cookie that has the longest matching path.

If the first argument is a string, they look for a cookie with that name using the hostname of the currently open page as the domain and / as the path. To be more specific, the first argument can be an object with the properties name, domain and path.

The following are equivalent:

browser.getCookie("session");
browser.getCookie({ name: "session",
                    domain: browser.location.hostname,
                    path: browser.location.pathname });

getCookie take a second argument. If false (or missing), it returns the value of the cookie. If true, it returns an object with all the cookie properties: name, value, domain, path, expires, httpOnly and secure.

browser.cookies

Returns an object holding all cookies used by this browser.

browser.cookies.dump(stream?)

Dumps all cookies to standard output, or the output stream.

browser.deleteCookie(identifier)

Deletes a cookie matching the identifier.

The identifier is either the name of a cookie, or an object with the property name and the optional properties domain and path.

browser.deleteCookies()

Deletes all cookies.

browser.getCookie(identifier, allProperties?)

Returns a cookie matching the identifier.

The identifier is either the name of a cookie, or an object with the property name and the optional properties domain and path.

If allProperties is true, returns an object with all the cookie properties, otherwise returns the cookie value.

browser.setCookie(name, value)

Sets the value of a cookie based on its name.

browser.setCookie(cookie)

Sets the value of a cookie based on the following properties:

• domain - Domain of the cookie (requires, defaults to hostname of currently open page)
• expires - When cookie it set to expire (Date, optional, defaults to session)
• maxAge - How long before cookie expires (in seconds, defaults to session)
• name - Cookie name (required)
• path - Path for the cookie (defaults to /)
• httpOnly - True if HTTP-only (not accessible from client-side JavaScript, defaults to false)
• secure - True if secure (requires HTTPS, defaults to false)
• value - Cookie value (required)

Tabs

Just like your favorite Web browser, Zombie manages multiple open windows as tabs. New browsers start without any open tabs. As you visit the first page, Zombie will open a tab for it.

All operations against the browser object operate on the currently active tab (window) and most of the time you only need to interact with that one tab. You can access it directly via browser.window.

Web pages can open additional tabs using the window.open method, or whenever a link or form specifies a target (e.g. target=_blank or target=window-name). You can also open additional tabs by calling browser.open. To close the currently active tab, close the window itself.

You can access all open tabs from browser.tabs. This property is an associative array, you can access each tab by its index number, and iterate over all open tabs using functions like forEach and map.

If a window was opened with a name, you can also access it by its name. Since names may conflict with reserved properties/methods, you may need to use browser.tabs.find.

The value of a tab is the currently active window. That window changes when you navigate forwards and backwards in history. For example, if you visited the URL "/foo" and then the URL "/bar", the first tab (browser.tabs[0]) would be a window with the document from "/bar". If you then navigate back in history, the first tab would be the window with the document "/foo".

The following operations are used for managing tabs:

browser.close(window)

Closes the tab with the given window.

browser.close()

Closes the currently open tab.

browser.tabs

Returns an array of all open tabs.

browser.tabs[number]

Returns the tab with that index number.

browser.tabs[string]

browser.tabs.find(string)

Returns the tab with that name.

browser.tabs.closeAll()

Closes all tabs.

browser.tabs.current

This is a read/write property. It returns the currently active tab.

Can also be used to change the currently active tabe. You can set it to a window (e.g. as currently returned from browser.current), a window name or the tab index number.

browser.tabs.dump(output)

Dump a list of all open tabs to standard output, or the output stream.

browser.tabs.index

Returns the index of the currently active tab.

browser.tabs.length

Returns the number of currently opened tabs.

browser.open(url: "http://example.com")

Opens and returns a new tab. Supported options are:

• name - Window name.
• url - Load document from this URL.

browser.window

Returns the currently active window, same as browser.tabs.current.

Assertions

To make life easier, Zombie introduces a set of convenience assertions that you can access directly from the browser object. For example, to check that a page loaded successfuly:

browser.assert.success();
browser.assert.text("title", "My Awesome Site");
browser.assert.element("#main");

These assertions are available from the browser object since they operate on a particular browser instance -- generally dependent on the currently open window, or document loaded in that window.

Many assertions require an element/elements as the first argument, for example, to compare the text content (assert.text), or attribute value (assert.attribute). You can pass one of the following values:

• An HTML element or an array of HTML elements
• A CSS selector string (e.g. "h2", ".book", "#first-name")

Many assertions take an expected value and compare it against the actual value. For example, assert.text compares the expected value against the text contents of one or more strings. The expected value can be one of:

• A JavaScript primitive value (string, number)
• undefined or null are used to assert the lack of value
• A regular expression
• A function that is called with the actual value and returns true if the assertion is true
• Any other object will be matched using assert.deepEqual

Note that in some cases the DOM specification indicates that lack of value is an empty string, not null/undefined.

All assertions take an optional last argument that is the message to show if the assertion fails. Better yet, use a testing framework like Mocha that has good diff support and don't worry about these messages.

Available Assertions

The following assertions are available:

assert.attribute(selection, name, expected, message)

Asserts the named attribute of the selected element(s) has the expected value.

Fails if no element found.

assert.className(selection, className, message)

Asserts that selected element(s) has that and only that class name. May also be space-separated list of class names.

Fails if no element found.

assert.cookie(identifier, expected, message)

Asserts that a cookie exists and has the expected value, or if expected is null, that no such cookie exists.

The identifier is either the name of a cookie, or an object with the property name and the optional properties domain and path.

assert.element(selection, message)

Asserts that one element matching selection exists.

Fails if no element or more than one matching element are found.

assert.elements(selection, count, message)

Asserts how many elements exist in the selection.

The argument count can be a number, or an object with the following properties:

• atLeast - Expecting to find at least that many elements
• atMost - Expecting to find at most that many elements
• exactly - Expecting to find exactly that many elements

assert.evaluate(expression, expected, message)

Evaluates the JavaScript expression in the context of the currently open window.

With one argument, asserts that the value is equal to true.

With two/three arguments, asserts that the returned value matches the expected value.

assert.global(name, expected, message)

Asserts that the global (window) property has the expected value.

assert.hasClass(selection, className, message)

Asserts that selected element(s) have the expected class name. Elements may have other class names (unlike assert.className).

Fails if no element found.

assert.hasFocus(selection, message)

Asserts that selected element has the focus.

If the first argument is null, asserts that no element has the focus.

Otherwise, fails if element not found, or if more than one element found.

assert.input(selection, expected, message)

Asserts that selected input field(s) (input, textarea, select etc) have the expected value.

Fails if no element found.

assert.hasNoClass(selection, className, message)

Asserts that selected element(s) does not have the expected class name. Elements may have other class names (unlike assert.className).

Fails if no element found.

assert.prompted(messageShown, message)

Asserts the browser prompted with a given message.

assert.redirected(message)

Asserts the browser was redirected when retrieving the current page.

assert.success(message)

Asserts the current page loaded successfully (status code 2xx or 3xx).

assert.status(code, message)

Asserts the current page loaded with the expected status code.

assert.style(selection, style, expected, message)

Asserts that selected element(s) have the expected value for the named style property. For example:

browser.assert.style(".navigation", "opacity", 0.5)

Fails if no element found.

assert.text(selection, expected, message)

Asserts that selected element(s) have the expected text content. For example:

browser.assert.text("title", "My Awesome Page")

Fails if no element found.

assert.url(url, message)

Asserts the current page has the expected URL.

The expected URL can be one of:

• The full URL as a string
• A regular expression
• A function, called with the URL and returns true if the assertion is true
• An object, in which case individual properties are matched against the URL

For example:

browser.assert.url("http://localhost/foo/bar")
browser.assert.url({ pathame: "/foo/bar" });
browser.assert.url({ query: { name: "joedoe" } });

Roll Your Own Assertions

Not seeing an assertion you want? You can add your own assertions to the prototype of Browser.Assert.

For example:

// Asserts the browser has the expected number of open tabs.
Browser.Assert.prototype.openTabs = function(expected, message) {
  assert.equal(this.browser.tabs.length, expected, message);
};

Or application specific:

// Asserts which links is highlighted in the navigation bar
Browser.Assert.navigationOn = function(linkText) {
  this.assert.element(".navigation-bar");
  this.assert.text(".navigation-bar a.highlighted", linkText);
};

Events

Each browser instance is an EventEmitter, and will emit a variety of events you can listen to.

Some things you can do with events:

• Trace what the browser is doing, e.g. log every page loaded, every DOM event emitted, every timeout fired
• Wait for something to happen, e.g. form submitted, link clicked, input element getting the focus
• Strip out code from HTML pages, e.g remove analytics code when running tests
• Add event listeners to the page before any JavaScript executes
• Mess with the browser, e.g. modify loaded resources, capture and change DOM events

console (level, message)

Emitted whenever a message is printed to the console (console.log, console.error, console.trace, etc).

The first argument is the logging level, and the second argument is the message.

The logging levels are: debug, error, info, log, trace and warn.

active (window)

Emitted when this window becomes the active window.

closed (window)

Emitted when this window is closed.

done ()

Emitted when the event loop goes empty.

evaluated (code, result, filename)

Emitted after JavaScript code is evaluated.

The first argument is the JavaScript function or code (string). The second argument is the result. The third argument is the filename.

event (event, target)

Emitted whenever a DOM event is fired on the target element, document or window.

focus (element)

Emitted whenever an element receives the focus.

inactive (window)

Emitted when this window is no longer the active window.

interval (function, interval)

Emitted whenever an interval (setInterval) is fired.

The first argument is the function or code to evaluate, the second argument is the interval in milliseconds.

link (url, target)

Emitted when a link is clicked.

The first argument is the URL of the new location, the second argument identifies the target window (_self, _blank, window name, etc).

loaded (document)

Emitted when a document has been loaded into a window or frame.

This event is emitted after the HTML is parsed, and some scripts executed.

loading (document)

Emitted when a document is about to be loaded into a window or frame.

This event is emitted when the document is still empty, before parsing any HTML.

opened (window)

Emitted when a new window is opened.

redirect (request, response)

Emitted when following a redirect.

The first argument is the request, the second argument is the response that caused the redirect. See Resources for more details.

The URL of the new resource to retrieve is given by response.url.

request (request)

Emitted before making a request to retrieve a resource.

The first argument is the request object. See Resources for more details.

response (request, response)

Emitted after receiving the response (excluding redirects).

The first argument is the request object, the second argument is the response object. See Resources for more details.

submit (url, target)

Emitted whenever a form is submitted.

The first argument is the URL of the new location, the second argument identifies the target window (_self, _blank, window name, etc).

timeout (function, delay)

Emitted whenever a timeout (setTimeout) is fired.

The first argument is the function or code to evaluate, the second argument is the delay in milliseconds.

Resources

Zombie can retrieve with resources - HTML pages, scripts, XHR requests - over HTTP, HTTPS and from the file system.

Most work involving resources is done behind the scenes, but there are few notable features that you'll want to know about. Specifically, if you need to do any of the following:

• Inspect the history of retrieved resources, useful for troubleshooting issues related to resource loading
• Simulate a failed server
• Change the order in which resources are retrieved, or otherwise introduce delays to simulate a real world network
• Mock responses from servers you don't have access to, or don't want to access from test environment
• Request resources directly, but have Zombie handle cookies, authentication, etc
• Implement new mechanism for retrieving resources, for example, add new protocols or support new headers

The Resources List

Each browser provides access to its resources list through browser.resources.

The resources list is an array of all resouces requested by the browser. You can iterate and manipulate it just like any other JavaScript array.

Each resource provides four properties:

• request - The request object
• response - The resource object (if received)
• error - The error received instead of response
• target - The target element or document (when loading HTML page, script, etc)

The request object consists of:

• method - HTTP method, e.g. "GET"
• url - The requested URL
• headers - All request headers
• body - The request body can be Buffer or string; only applies to POST and PUT methods
• multiparty - Used instead of a body to support file upload
• time - Timestamp when request was made
• timeout - Request timeout (0 for no timeout)

The response object consists of:

• url - The actual URL of the resource; different from request URL if there were any redirects
• statusCode - HTTP status code, eg 200
• statusText - HTTP static code as text, eg "OK"
• headers - All response headers
• body - The response body, may be Buffer or string, depending on the content type encoding
• redirects - Number of redirects followed (0 if no redirects)
• time - Timestamp when response was completed

Request for loading pages and scripts include the target DOM element or document. This is used internally, and may also give you more insight as to why a request is being made.

Mocking, Failing and Delaying Responses

To help in testing, Zombie includes some convenience methods for mocking, failing and delaying responses.

For example, to mock a response:

browser.resources.mock("http://3rd.party.api/v1/request", {
  statusCode: 200,
  headers:    { "ContentType": "application/json" },
  body:       JSON.stringify({ "count": 5 })
})

In the real world, servers and networks often fail. You can test to for these conditions by asking Zombie to simulate a failure. For example:

browser.resource.fail("http://3rd.party.api/v1/request");

Another issue you'll encounter in real-life applications are network latencies. When running tests, Zombie will request resources in the order in which they appear on the page, and likely receive them from the local server in that same order.

Occassionally you'll need to force the server to return resources in a different order, for example, to check what happens when script A loads after script B. You can introduce a delay into any response as simple as:

browser.resources.delay("http://3d.party.api/v1/request", 50);

The Pipeline

Zombie uses a pipeline to operate on resources. You can extend that pipeline with your own set of handlers, for example, to support additional protocols, content types, special handlers, better resource mocking, etc.

The pipeline consists of a set of handlers. There are two types of handlers:

Functions with two arguments deal with requests. They are called with the request object and a callback, and must call that callback with one of:

• No arguments to pass control to the next handler
• An error to stop processing and return that error
• null and the response objec to return that response

Functions with three arguments deal with responses. They are called with the request object, response object and a callback, and must call that callback with one of:

• No arguments to pass control to the next handler
• An error to stop processing and return that error

To add a new handle to the end of the pipeline:

browser.resources.addHandler(function(request, next) {
  // Let's delay this request by 1/10th second
  setTimeout(function() {
    Resources.httpRequest(request, next);
  }, Math.random() * 100);
});

If you need anything more complicated, you can access the pipeline directly via browser.resources.pipeline.

You can add handlers to all browsers via Browser.Resources.addHandler. These handlers are automatically added to every new browser.resources instance.

Browser.Resources.addHandler(function(request, response, next) {
  // Log the response body
  console.log("Response body: " + response.body);
  next();
});

When handlers are executed, this is set to the browser instance.

Operating On Resources

If you need to retrieve of operate on resources directly, you can do that as well, using all the same features available to Zombie, including mocks, cookies, authentication, etc.

resources.addHandler(handler)

Adds a handler to the pipeline of this browser instance. To add a handler to the pipeline of every browser instance, use Browser.Resources.addHandler.

resources.delay(url, delay)

Retrieve the resource with the given URL, but only after a delay.

resources.dump(output)

Dumps the resources list to the output stream (defaults to standard output stream).

resources.fail(url, error)

Do not attempt to retrieve the resource with the given URL, but act as if the request failed with the given message.

This is used to simulate network failures (can't resolve hostname, can't make connection, etc). To simulate server failures (status codes 5xx), use resources.mock.

resources.pipeline

Returns the current pipeline (array of handlers) for this browser instance.

resources.get(url, callback)

Retrieves a resource with the given URL and passes response to the callback.

For example:

browser.resources.get("http://some.service", function(error, response) {
  console.log(response.statusText);
  console.log(response.body);
});

resources.mock(url, response)

Do not attempt to retrieve the resource with the given URL, but return the response object instead.

resources.post(url, options, callback)

Posts a document to the resource with the given URL and passes the response to the callback.

Supported options are:

• body- Request document body
• headers - Headers to include in the request
• params - Parameters to pass in the document body
• timeout - Request timeout in milliseconds (0 or null for no timeout)

For example:

var params  = { "count": 5 };
browser.resources.post("http://some.service",
                       { params: params },
                       function(error, response) {
  . . .
});

var headers = { "Content-Type": "application/x-www-form-urlencoded" };
browser.resources.post("http://some.service",
                       { headers: headers, body: "count=5" },
                       function(error, response) {
   . . .
});

resources.request(method, url, options, callback)

Makes an HTTP request to the resource and passes the response to the callback.

Supported options are:

• body- Request document body
• headers - Headers to include in the request
• params - Parameters to pass in the query string (GET, DELETE) or document body (POST, PUT)
• timeout - Request timeout in milliseconds (0 or null for no timeout)

For example:

browser.resources.request("DELETE",
                          "http://some.service",
                          function(error) {
  . . .
});

resources.restore(url)

Reset any special resource handling from a previous call to delay, fail or mock.