Automation By Meta

All that is needed to drive automation from specifications is at least one more specification.

In the previous post we used the REPL console in gwen-web to interactively complete the floodio challenge one step at a time. In this post we will use a lot of the same steps again but will automate the entire challenge through a feature file instead. Like before, there will be no need to compile any code. But unlike before, we will introduce some custom steps and compose step definitions for those in a meta file.

Before proceeding, be sure to install gwen-web if you have not done so already and open a command prompt to your installation directory.

Writing the Feature

Features should be self documenting.

We start by writing a FloodIO.feature file containing the content shown below. For convenience, create this file in the root of your gwen-web installation. You can use any plain text editor you like. This will be the feature specification that we will use to automate the challenge.

   Feature: Complete the floodio challenge
       As a gwen user
       I want to automate the floodio challenge
       So that I can verify that it works

  Scenario: Launch the challenge
      Given I launch the floodio challenge
       Then I should be on the start page

  Scenario: Complete step 1
      Given I am on the start page
       When I click the Start button
       Then I should be on the step 2 page

  Scenario: Complete step 2
      Given I am on the step 2 page
       When I select "21" in the how old are you dropdown
        And I click the next button
       Then I should be on the step 3 page
       
  Scenario: Complete step 3
      Given I am on the step 3 page
       When I select and enter the largest order value
        And I click the next button
       Then I should be on the step 4 page
   
  Scenario: Complete step 4
      Given I am on the step 4 page
       When I click the next button
       Then I should be on the step 5 page

  Scenario: Complete step 5
      Given I am on the step 5 page
       When I enter the one time token
        And I click the next button
       Then I should be on the challenge completed page

The above specification consists of a feature declaration followed by several scenarios. The feature declaration is merely documentation. It has a name followed by an “As a.. I want.. So that..” story-like description spanning three lines.

Each scenario has a name and a sequence of steps. If you look carefully you will discover that the steps in the feature are not the same set of steps we previously used to complete the challenge in the REPL. There are several reasons for this:

1. We are writing the feature first and want it to read well.
2. We are grouping steps into scenarios.
3. We expect that all steps will execute one after the other in rapid succession when sourced from a feature file. In the REPL, pages had plenty of time to load between manually entering steps. But in batch mode we will not get any free page loading time between steps. We therefore have to introduce additional steps that will explicitly wait for pages to load before subsequent steps interact with those pages.

Writing the Meta

We are now ready to identify and compose the custom steps we have introduced. The easiest way to do this is to launch the feature and define a step definition for every step that fails to execute because it is undefined, and then repeat the process until there are no more undefined steps. We start using that approach now and issue the following command in the root of our gwen-web installation to launch the feature in batch mode (using the -b option). Batch mode forces the gwen session to exit as soon as the feature exits.

bin/gwen -b FloodIO.feature

The output shows that the first step fails:

ERROR - Unsupported step: Given I launch the floodio challenge

This error reports that an unsupported step has been found and identifies which one it was. We can be sure now that this is a custom step and so immediately compose a step definition for it. To do this, create a new file called FloodIO.meta in the root of your gwen-web installation (alongside the feature file) and update it with the following content. Again, use any plain text editor you like.

   Feature: floodio meta
  
  @StepDef
  Scenario: I launch the floodio challenge
      Given I navigate to "https://challengers.flood.io/start"

Notice that we composed this new step definition by simply declaring a Scenario that:

• Is annotated with the @StepDef tag
• Has the name ‘I launch the floodio challenge‘. Note that the ‘Given’ keyword prefix is omitted from this name.
• Contains one step that launches the browser and navigates to the challenge url.

The above step definition contains only a single step. This effectively makes ‘I launch the floodio challenge‘ an alias for ‘I navigate to https://challengers.flood.io/start‘. This may not seem very useful but what it does do in this instance is externalise the URL to the meta file. The URL is considered configuration data and therefore should be in the meta file and not the feature file.

Now when this meta is loaded, the bound navigation step will execute whenever ‘I launch the floodio challenge‘ is referenced by a step running in the interpreter.

The ‘When’, ‘Then’, ‘And’, or ‘But’ keywords would also work in place of the ‘Given’ keyword in the calling step. Which keyword you use is up to you, but you should consider both fluency and context when authoring your own features.

Next, we launch the feature again to confirm that the step now works. But this time we do it in interactive mode (without using the -b option) so that the browser remains open and the REPL mode starts after the feature exits.

bin/gwen FloodIO.feature

Gwen will automatically find the meta file if it is in the same directory as (or somewhere in the path of) the feature file. If you saved the meta somewhere else, then you can specify its location using the -m option.

The step we just composed now works and its output looks good. The start page has loaded in the browser and the console has reported a ‘Passed’ status for it. But now we get the following error on the next step:


ERROR - on the start page not found in https://challengers.flood.io/start scope
ERROR - [0.0041 secs] Failed Step: Then I should be on the start page


This error suggests that something called ‘on the start page’ could not be found in the https://challengers.flood.io/start scope. This is because the expression ‘I should be on the start page‘ happens to match ‘x should be y‘ which is a predefined step in the gwen-web engine that compares some value x to some value y. But our intention with this step was to assert that we are on the start page and not to compare values. Errors like this can sometimes be tricky to diagnose. Fortunately the second error line shows exactly which step failed and we can immediately identify it as being a custom step that we know we have not defined. So we proceed to add a step definition for it in our meta file as follows:

   Feature: floodio meta
        
  @StepDef
  Scenario: I launch the floodio challenge
      Given I navigate to "https://challengers.flood.io/start"
      
  @StepDef 
  Scenario: I should be on the start page
      Given I wait until "$('h2').text().trim() == 'Welcome'"
       Then I am on the start page
        And the heading can be located by tag name "h2"
        And the heading should be "Welcome"
        And the Start button can be located by name "commit"

As before, we defined this step definition as a Scenario and annotated it with the @StepDef tag, but this time we named it ‘I should be on the start page‘ and bound five steps to it:

• The first step waits for the javascript predicate “$('h2').text().trim() == 'Welcome'” to return true. We consider the start page to be loaded when the ‘Welcome’ heading is rendered in the browser. Simply checking the heading is sufficient in this case, but other pages on other sites could require more sophisticated checks. It’s up to you to discover what constitutes a page load and tailor a suitable predicate to match.
• The second step puts the start page in scope
• The third step defines the locator binding for the heading
• The fourth step checks that the rendered heading is ‘Welcome’. Although the predicate in the first step already does this, it is good practice to always check the heading (or some other text) on every page after it loads regardless. It just so happens in this instance that the predicate checks the same heading. But this will not always be so.
• The fifth step defines the locator binding for the Start button

We now type exit in the previous gwen session to close it and launch the feature again to confirm that the above works.

bin/gwen FloodIO.feature

We observe from the output that the custom step does work and that we have progressed beyond the first page and have made it to the second page of the challenge in the browser. We also observe that the following two steps executed successfully:

Given I am on the start page
 When I click the Start button

This is because these are not custom steps, but rather predefined steps in gwen-web. The embedded web engine in the interpreter knows how to execute them without us having to do anything. But we do again fail with a similar error to the one we got last time on the custom step that follows.

ERROR - on the step 2 page not found in start page scope
ERROR - [0.0020 secs] Failed Step: Then I should be on the step 2 page

The Completed Meta

Repeating the process for the remaining custom steps (and doing some refactoring as we go to eliminate redundancies) yields the complete meta specification below. Most of the steps in this meta are borrowed from the previous post. We simply bound them here to step definitions and mapped them by name to the custom steps in our feature.

   Feature: floodio meta
  
  Scenario: Initialise
      Given the heading can be located by tag name "h2"
        And the next button can be located by class name "btn"
       
  @StepDef
  Scenario: I launch the floodio challenge
      Given I navigate to "https://challengers.flood.io/start"
  
  @StepDef 
  Scenario: I should be on the start page
      Given I wait until "$('h2').text().trim() == 'Welcome'"
       Then I am on the start page
        And the heading should be "Welcome"
        And the Start button can be located by name "commit"

  @StepDef
  Scenario: I should be on the step 2 page
      Given I wait until "$('h2').text().trim() == 'Step 2'"
       Then I am on the step 2 page
        And the heading should be "Step 2"
        And the how old are you dropdown can be located by id "challenger_age"

 @StepDef
  Scenario: I should be on the step 3 page
      Given I wait until "$('h2').text().trim() == 'Step 3'"
       Then I am on the step 3 page
        And the heading should be "Step 3"
        And the largest order value field can be located by id "challenger_largest_order"
        And the largest order value can be located by javascript "$('.radio:contains(' + Math.max.apply(Math, $.map($('.radio'), function(x) { return parseInt($(x).text()); })) + ')').get(0);"
      
  @StepDef  
  Scenario: I should be on the step 4 page
      Given I wait until "$('h2').text().trim() == 'Step 4'"
       Then I am on the step 4 page
        And the heading should be "Step 4"
        
  @StepDef
  Scenario: I should be on the step 5 page
      Given I wait until "$('h2').text().trim() == 'Step 5'"
       Then I am on the step 5 page
        And the heading should be "Step 5"
        And the one time token can be located by css selector ".token"
        And the one time token field can be located by id "challenger_one_time_token"
        
  @StepDef
  Scenario: I should be on the challenge completed page
      Given I wait until "$('h2').text().trim() == "You're Done!""
       Then I am on the challenge completed page
        And the heading should be "You're Done!"
     
  @StepDef
  Scenario: I select and enter the largest order value
      Given I capture the largest order value
        And I type the largest order value in the largest order value field
        And I click the largest order value
  
  @StepDef
  Scenario: I enter the one time token
      Given I wait for the one time token text
        And I capture the one time token
        And I type the one time token in the one time token field

Conclusion

With the meta complete and all custom steps resolved, we now have a fully executable feature file for automating the floodio challenge. We did this by writing the feature specification first and composing the meta specification second to make the feature executable “as is” (without modifying it whatsoever).

Launching the feature should now always result in success, unless something has changed in the application or it suddenly goes offline.

bin/gwen -b FloodIO.feature

Reports

If you want to also generate reports:

bin/gwen -b -r target/reports FloodIO.feature

A HTML report will be available at target/reports/feature-summary.html.

Tips

The approach presented here can be used to automate any web application and works consistently well across the four major browsers. The core tips for doing it right include:

• Composing a custom step that will take you to the entry point of the application. The step definition for this should include all the necessary steps to get you there.
• Composing custom wait steps for each page. For any given page, you must first wait for that page to load through an appropriately tailored JavaScript predicate before putting the page in scope, binding its locators, and performing actions and assertions on it.
• Creating all conditions and asserting all expectations for completeness.

Next Time

In the next post we will look at meta overrides and see how they can be used to bind environment and user data.

Page Objects Begone

Because we can emulate them with page scopes instead.

Page objects are a commonly used design pattern for developing web tests with Selenium web driver. But coding page objects and tests to an API is a very developer centric activity. The role of a tester is to write and execute tests and not to develop and compile code. The same can be said for developers when they put their test hats on.

Gherkin features that describe the expected behavior of a system are good enough to drive tests. There is no need for a sophisticated UI that requires up front modelling and compilation to generate tests. It is much simpler to just specify the expected behavior in plain text and have an interpreter dynamically evaluate it against the system under test.

Introducing gwen-web

gwen-web is a tool that aims to give testers this dynamic capability and do away with page objects and compilation altogether. It is powered by gwen; an interpreter that maps gherkin features to executable code. In the case of gwen-web, it maps Gherkin features to precompiled Selenium code to drive a web browser. As a user of this tool, you never have to write any Selenium code or develop any page objects at all.

Page Scopes

Gwen-web introduces the concept of page scopes. A page scope is a stack of name-value pairs bound to a namespace in memory. They can be used to store information about individual pages and how their web elements can be located. In this way gwen does not store or manage any web element references but rather just binds their names to locator expressions (or lookup strings) that you provide. You specify what pages and bindings you require through a prescribed DSL that gwen-web knows how to interpret and understand.

It is best to illustrate with an example. The floodio challenge walks you through a series of web pages that prompt you to perform some tasks. In the remainder of this post, we will use the gwen REPL (Read-Eval-Print Loop) console to perform these tasks and complete the challenge.

Build and install gwen-web from source – Note that gwen-web is an open source project (and at this time of writing) is currently still under development and a binary release is not yet available. On the bright side it is fully functional and you can download the source and build and install it on your local machine by following the instructions here. Gwen is written in Scala and you will need to download the sbt build tool to build it (the details are in the instructions). But once built, you only need Java to run it.

Update 18 Nov 2014 – Build and install gwen-web from a binary distribution – Distributable gwen-web binaries (zips) are now available. See install instructions here.

After completing the installation, open a command prompt to your installed gwen-web directory and enter the following command:

bin/gwen

REPL Console

The gwen REPL will start and you will see the following console displayed:

The REPL is case sensitive and does not accept fuzzy input. So be sure to enter all steps and commands exactly as shown in this post.

When gwen starts up, it always implicitly creates and activates a default feature scope with no bindings in it. This is a global scope that can be used to set bindings for elements that are common and accessible across multiple pages (the entire feature).

The first thing we will do is create and activate a new page scope for the floodio start page. No need to write a page object, just type the following into the gwen prompt and hit enter:

When I am on the start page

Gwen will create a new page scope called “start” and activate it in memory before informing you that it has successfully completed the step. If you enter env at the gwen prompt, you will see the output of the environment context in memory and our newly created page scope called “start” at the bottom.

{
  "scopes" : [ {
    "scope" : "feature",
    "atts" : [ ]
  }, {
    "scope" : "start",
    "atts" : [ ]
  } ]
}

All we have done here is defined a new page scope called “start” and made it the currently active scope. Now we will store the url of the floodio start page into this scope so that gwen can know where to navigate to. Enter the following to bind the floodio start page URL to the currently active “start” page scope:

Then the url will be "https://challengers.flood.io/start"

When it successfully completes, enter env at the prompt again to see our bound URL:

{
  "scopes" : [ {
    "scope" : "feature",
    "atts" : [ ]
  }, {
    "scope" : "start",
    "atts" : [ {
      "url" : "https://challengers.flood.io/start"
    } ]
  } ]
}

We have now told gwen what the url of the floodio start page is. We will now instruct gwen to open a browser to that page. Enter the following, and observe!

Given I navigate to the start page

This step will start a new browser window, locate the URL for the start page, and point the browser to that location.

Gwen-web supports the Firefox, Chrome, Safari, and IE browsers. It uses Firefox as the default browser since it does not require you to install a native web driver on your local machine. To use a different browser, follow the instructions in this user guide.

Now we will tell gwen how to locate the Start button that appears on the start page. But to do that, we need to know how the button has been defined on the page. If you right click the Start button in the browser page and click “inspect element”, you will see that it is defined as an input element with a name attribute set to “commit”.

<input class="btn blue" name="commit" value="Start" type="submit">

Now enter the following at the gwen prompt to bind this information to the “start” page scope that is currently active:

And the Start button can be located by name "commit"

Type env at the command prompt again if you would like to see how this locator information is bound to memory.

Before continuing, be sure to close the “inspect element” pane if you still have it open in your browser. Leaving it open may interfere with gwen and could result in errors.

Now enter the following to verify that gwen can locate the Start button:

And I highlight the Start button

This step locates the Start button and highlights it for a short time. You should see the Start button being highlighted and then unhighlighted.

This confirms that gwen can locate the button and that we have bound the locator correctly. Now enter the following to have gwen click the Start button:

When I click the Start button

Gwen will now click the Start button and the browser will navigate to the next page.

To proceed from here, we again first need to create a new page scope for this page, and then tell gwen how to locate the elements we wish to interact with. Enter the following to create a new page scope for this page:

Then I am on the step 2 page

This will create a new empty page scope in memory called “step 2″ and make it the currently active scope. If you type env at the command prompt, you will see it printed at the bottom.

{
  "scopes" : [ {
    "scope" : "feature",
    "atts" : [ ]
  }, {
    "scope" : "step 2",
    "atts" : [ ]
  } ]
}

By default, the env command displays only the currently visible scopes (in this case, the feature and step 2 scope). To display all scopes (including our previously created start scope), you need to specify the -all switch.

To see all scopes, type env -a:

{
  "scopes" : [ {
    "scope" : "feature",
    "atts" : [ ]
  }, {
    "scope" : "start",
    "atts" : [ {
      "url" : "https://challengers.flood.io/start"
    }, {
      "the Start button/locator" : "name"
    }, {
      "the Start button/locator/name" : "commit"
    }, {
      "the Start button/click" : "true"
    } ]
  }, {
    "scope" : "step 2",
    "atts" : [ ]
  } ]
}

All page scopes are managed in memory as JSON objects on a stack with the most recently active scope appearing at the bottom. For more details about how this stack works, you can study the documented source on the gwen project site here.

Moving on, we can now proceed to bind the locator information for the ‘how old are you’ dropdown and the ‘Next’ button elements that appear on the step 2 page. If you inspect these elements in the page source, you will find that they are defined as follows:

<select class="select optional" id="challenger_age" name="challenger[age]">
  <option value="">How old are you?</option>
  <option value="18">18</option>
  <option value="19">19</option>
  ...
</select>

<input class="btn" name="commit" value="Next" type="submit">

Again, be sure to close the “inspect element” pane (if you opened it) in the browser before continuing.

Enter the following into the gwen prompt to let gwen know how to locate the ‘how old are you’ dropdown element (in this instance we locate it by Id).

Given the how old are you dropdown can be located by id "challenger_age"

Now for the next button. We could locate it by name in the same way we did for the Start button on the start page, but to mix things up a bit (and because we can), we will locate it by class instead. Enter the following to let gwen know how to locate the next button:

And the next button can be located by class name "btn"

You can confirm that both of these locators work by entering the following steps in the console (one after the other) to highlight them:

And I highlight the how old are you dropdown
And I highlight the next button

After confirming the above, we can proceed to select an age and click the next button before creating a scope for the next page:

And I select "21" in the how old are you dropdown
And I click the next button
Then I am on the step 3 page

We are now on the step 3 page. Here we need to select and enter the largest order value from the list of radio buttons displayed on the page.

How do we instruct gwen to find the largest order value? Lets see if we can find it with some JQuery scripting first. Open the browser console view and enter the following lines of script to locate the largest order value:

var orderRadios = $('.radio'); 
var orderValues = $.map(orderRadios, function(x) { return parseInt($(x).text()); });
var maxValue = Math.max.apply(Math, orderValues);
var maxRadio = $('.radio:contains("' + maxValue + '")');
$(maxRadio).text(); // should return largest order value

The above can be reduced to a one-liner to get the maxRadio element as follows:

$('.radio:contains(' + Math.max.apply(Math, $.map($('.radio'), function(x) { return parseInt($(x).text()); })) + ')');

We have shown above that we can locate the largest order value using JQuery. Luckily for us, gwen-web allows us to locate elements by JavaScript (but only through one liner expressions). Futhermore, if the page in the browser has loaded the JQuery library then we can use it too. Now enter the following into the console so that gwen can know how to locate the element containing the highest order value (note that we use the one-liner expression version here to locate and return the element):

Given the largest order value can be located by javascript "$('.radio:contains(' + Math.max.apply(Math, $.map($('.radio'), function(x) { return parseInt($(x).text()); })) + ')').get(0);"

Now enter the following to highlight the largest order value and confirm that the locator works:

And I highlight the largest order value

We had to use some JQuery scripting here to locate the largest order value. Scripting is necessary in this case because we need to enter values and select buttons based on the results of functions applied to the elements and values on this page. This is a good example of an interaction that cannot be readily automated without some level of scripting. For this reason, gwen-web supports locating elements by javascript.

The other things we need to locate on this page are the input field into which we will need to enter the largest order value into and the next button. We define the location of these by entering the following:

And the largest order value field can be located by id "challenger_largest_order"
And the next button can be located by class name "btn"

We are now ready to let gwen find the largest order value, type it into the input field, click the radio button for that value, and then click next. We do that by entering the following steps:

Given I capture the largest order value
And I type the largest order value in the largest order value field
When I click the largest order value
And I click the next button
Then I am on the step 4 page

The step 4 page merely asks us to click the next button when we are ready. We do this straight away by entering the following:

Given the next button can be located by class name "btn"
When I click the next button
Then I am on the step 5 page

This will bring us to the step 5 page (the last page in the floodio challenge).

This page requires that we copy a provided token value into a field and then click next. Inspecting the page source reveals that the token is displayed in a span element defined with a class="token" attribute. The input field has an id of “challenger_one_time_token”, and the next button is defined in the same way it was in the previous pages. We now define locators for these by entering:

Given the one time token can be located by css selector ".token"
And the one time token field can be located by id "challenger_one_time_token"
And the next button can be located by class name "btn"

If you take a closer look at the source you will see that the token value is actually loaded by an ajax request when the page is loaded. Waiting for this value to load is not a problem when running gwen in REPL mode as the ajax request will have most likely completed in the time that the REPL is idly waiting for us to enter the next step at the prompt. But if we were running all the steps we’ve entered so far very quickly (as if in automated batch mode), then we would need to wait for the ajax request to complete and the token value to be populated first before attempting to access the value. Enter the following to have gwen wait for the token value to be populated (note: if the token is already populated, then gwen will immediately return without waiting).

And I wait for the one time token text

Now that we know the token is loaded, we can proceed to copy it into the input field and click the next button to complete the challenge. Enter the following steps to do that:

Given I capture the one time token
And I type the one time token in the one time token field
When I click the next button
Then I am on the done page

This will take us to the done page, telling us that we’re done.

To finish, type exit at the gwen prompt. The browser and the REPL will shut down.

Separation of Concerns

Two major benefits that page objects provide include the separation of test logic from configuration and the elimination of unwanted redundancies. Gwen can provide these same benefits through meta features.

Configuration by Meta

A meta feature is simply a configuration specification expressed as a gherkin feature (a feature describing a feature if you like). Recall that some of the steps we typed into the REPL above just configure (or tell gwen) what the url to a page is or how an element on a page can be located. This configuration information can all be captured in a meta feature file and loaded into gwen on startup. We can also eliminate duplicated steps and other redundancies too. For example, you will have noticed that the step that configures the next button locator was repeated above for every page that contains a next button. Since this button is common across multiple pages, it makes sense to define it once and reuse it. This can be done by binding it to the global feature scope that is implicitly created and activated by gwen when it starts up.

So we can now capture all the configuration steps into a single meta feature file. Note that this meta is representative of everything that would otherwise need to be programmed into a page object. But with gwen meta features, that programming is never necessary.

Now create a new file called floodio.meta in your gwen-web install directory and edit it to contain the following meta specification:

 Feature: Flood IO Meta

Scenario: Configure common locators
    Given the next button can be located by class name "btn"

Scenario: Configure start page
     When I am on the start page
     Then the url will be "https://challengers.flood.io/start"
      And the Start button can be located by name "commit"

Scenario: Configure step 2 page
     When I am on the step 2 page
     Then the how old are you dropdown can be located by id "challenger_age"

Scenario: Configure step 3 page
     When I am on the step 3 page
     Then the largest order value can be located by javascript "$('.radio:contains(' + Math.max.apply(Math, $.map($('.radio'), function(x) { return parseInt($(x).text()); })) + ')').get(0);"
      And the largest order value field can be located by id "challenger_largest_order"

Scenario: Configure step 4 page
   # noop - this page only has a next button (we have already defined a common locator for it above)
    
Scenario: Configure step 5 page
     When I am on the step 5 page
     Then the one time token can be located by css selector ".token"
      And the one time token field can be located by id "challenger_one_time_token"

Loading Meta

The above meta can now be loaded into gwen on startup through the -m command line option as follows:

bin/gwen -m floodio.meta

You will notice this time that the REPL console will load the meta when it starts up.

You can type env -a at the gwen prompt to view all the meta bindings in memory:

{
  "scopes" : [ {
    "scope" : "feature",
    "atts" : [ {
      "the next button/locator" : "class name"
    }, {
      "the next button/locator/class name" : "btn"
    } ]
  }, {
    "scope" : "start",
    "atts" : [ {
      "url" : "https://challengers.flood.io/start"
    }, {
      "the Start button/locator" : "name"
    }, {
      "the Start button/locator/name" : "commit"
    } ]
  }, {
    "scope" : "step 2",
    "atts" : [ {
      "the how old are you dropdown/locator" : "id"
    }, {
      "the how old are you dropdown/locator/id" : "challenger_age"
    } ]
  }, {
    "scope" : "step 3",
    "atts" : [ {
      "the largest order value/locator" : "javascript"
    }, {
      "the largest order value/locator/javascript" : "$('.radio:contains(' + Math.max.apply(Math, $.map($('.radio'), function(x) { return parseInt($(x).text()); })) + ')').get(0);"
    }, {
      "the largest order value field/locator" : "id"
    }, {
      "the largest order value field/locator/id" : "challenger_largest_order"
    } ]
  }, {
    "scope" : "step 5",
    "atts" : [ {
      "the one time token/locator" : "css selector"
    }, {
      "the one time token/locator/css selector" : ".token"
    }, {
      "the one time token field/locator" : "id"
    }, {
      "the one time token field/locator/id" : "challenger_one_time_token"
    } ]
  } ]
}

Now we can open a new browser session to the floodio start page and click the start button by entering only the following steps into the REPL:

Given I navigate to the start page
When I click the Start button
Then I am on the step 2 page

And similarly for the remaining pages..

Step 2 page:

Given I select "21" in the how old are you dropdown
When I click the next button
Then I am on the step 3 page

Step 3 page:

Given I capture the largest order value
And I type the largest order value in the largest order value field
And I click the largest order value
When I click the next button
Then I am on the step 4 page

Step 4 page:

When I click the next button
Then I am on the step 5 page

Step 5 page:

Given I wait for the one time token text
And I capture the one time token
And I type the one time token in the one time token field
When I click the next button
Then I am on the done page

When ready, type exit to close the browser and quit the REPL.

Conclusion

In this post, we used the gwen REPL to directly interact with a web application from scratch. We then factored out the configuration steps into a meta feature and loaded that into the REPL and interacted with the same web application again without reentering any of the configuration steps. We did it all with no page objects too! :)

Next..

In the next post we will write a feature file to automate the same floodio challenge in batch mode and generate evaluation reports. We will also compose custom step definitions and perform some assertions on each page. Lastly we will solve some common ajax and page loading problems that arise when automating web tests.

Update 12 Jan 2015 – As promised, here is the follow up post.

One Gwen Interpreter, Many Evaluation Engines

There is so much more that can be automated with Gherkin.

In the previous post, I announced the open sourcing of the gwen project. In this post I will introduce the interpreter and evaluation engine concepts and describe the difference and relationship between them.

The Gwen interpreter translates Gherkin features into executable code. The code that each step is translated to is not defined in the interpreter itself, but rather in separate modules called evaluation engines. When a feature is executed, the interpreter delegates the processing of each step to a mixed in engine that you define or provide. This is necessary since evaluation varies across systems and it would be futile to try and code for every conceivable behavior in one implementation. For this reason Gwen abstracts the evaluation engine to support many implementations. In this way, you decide which engine to use based on the type of system you want to evaluate. For example, if you want to evaluate the behavior of a web application, then you would use a web engine. Each engine must prescribe a DSL and use at least one API to interact with its target system.

Engines can be defined to replicate any software process that is reproducible through one or more API’s.

There are many useful engines that can be built. A web engine for automating web application testing is an obvious one that comes to mind (and one that we have already built). But gwen engines need not be confined to just testing. Engines can be defined to automate, emulate, or simulate any process that is repeatable through software. Engines can also be built to generate data and other resources too.

In summary,

• The interpreter reads in Gherkin features and dispatches the processing of all steps to an engine.
• Engines process all steps and create conditions, perform actions, and assert expectations on target systems.

I hope that many engines emerge from the community and that many of them are shared for everyone to download and use. But everyone is also permitted to build their own proprietary or commercial engines too.

Gwen – A Gherkin DSL Interpreter

One platform for many types of automation.

Gherkin is a language for describing software behavior. Any software behavior. It makes sense then to use it for evaluating software behavior too. But how can one evaluate any software behavior against any type of system with the one language?

A Gherkin interpreter with an abstracted evaluation engine could be one way to do it.

This interpreter would accept Gherkin features and dispatch the processing of each step to an evaluation engine for processing. You could implement your own specialised engines with specifically prescribed DSLs. The interpreter would translate plain text specifications into executing instructions and report the evaluated results. It would support sequential or parallel execution. It would also have a REPL. It would provide all the necessary processing and tooling required to interpret gherkin features and make them executable. A public library of engines would emerge and be shared for download. The one interpreter would work with all of them.

It’s a simple idea that a colleague and I have been working on. We haven’t built an extensive library of engines, but we have built one platform that many engines can be built on and one interpreter that any engine can be mixed into. We wrote it in Scala and open sourced it as a project called gwen.

• https://github.com/gwen-interpreter/gwen

Check it out and have a play. We would like to get some feedback and help from the community before publishing a 1.0 release.

How I defeated the maven-release-plugin in a flat structured multi module project

Rules are made to be broken so that paradoxes can be created.

Maven is a handy tool and has a lot of available plugins. It adopts the convention over configuration philosophy and provides a standard build lifecycle out of the box. This makes it very easy to automate a build and release process without writing a single line of script. But there’s a catch! It only works if you do things the “maven way” and follow the maven rules.

Most projects are made up of one or more multiple smaller projects. In the maven world, such projects are called multi module projects. A multi module project has a parent project and one or more nested child projects known as modules. When you build the parent project the child projects are also built. The recommended maven way of structuring a multi module project is to mirror the parent child hierarchy using a nested project structure.

So maven recommends that you create a parent project that contains the child projects using a physical project structure like this:

workspace/parent/pom.xml
workspace/parent/child1/pom.xml
workspace/parent/child2/pom.xml

Modules are then declared in the parent POM like this:

<modules>
  <module>child1</module>
  <module>child2</module>
</modules>

This was good for maven but it was is not good for eclipse. The eclipse IDE does not support nested projects. This was clearly a problem! I wanted to import all my projects (parent and children) into eclipse but the nested structure made this impossible. So I decided to use a flat project structure instead and moved all my child projects out of the parent project.

Now my parent and child projects were organised in a flat physical structure like this:

workspace/parent/pom.xml
workspace/child1/pom.xml
workspace/child2/pom.xml

And I then redefined the maven modules in the parent POM like this:

<modules>
  <module>../child1</module>
  <module>../child2</module>
</modules>

Now I could import all my projects into eclipse. This worked well and life was good until I decided to use the maven release plugin to automate the release process. I learned the hard way that the release plugin only supports the nested project structure recommended by maven. Reverting back to the nested structure was not an option. I had broken a maven rule and was being punished for it! I needed a paradoxical solution that would support both the nested and flat structures at the same time. It was then that I realised that my parent POM was responsible for two things: POM inheritance and module composition. It served two “parental” roles. In one role it provided all the common properties, dependencies, plugins, and profiles to all children through inheritance and in the other it defined itself as the parent project of all child projects. In OO terms, this was akin to defining a superclass that contains a list of all its subclasess.

My parent POM had violated the single responsibility principle. So I decided to split it up into two separate parent POMs. I removed the modules declaration from the original POM in my parent project. This POM was now purely to be used for inheritance purposes only. All child POMs continued to reference this POM as the parent POM. Nothing changed there. I then created a new POM that inherited this modified POM and aggregated all the other child POMs. I placed this new top level POM file in the workspace root alongside all my existing projects. My flat project structure now had a top level POM file that defined all the child projects as modules.

The final project structure looked like this:

workspace/pom.xml
workspace/parent/pom.xml
workspace/child1/pom.xml
workspace/child2/pom.xml

The workspace/parent/pom.xml was inherited by all child POMs and also the top level workspace/pom.xml. It was the parent POM for inheritance purposes. The top level workspace/pom.xml aggregated all the child projects into one container project. It was the (root) parent POM for composition purposes. It defined the parent and child modules like this:

<parent>
  <groupId>?</groupId>
  <artifactId>?</artifactId>
  <version>?</version>
  <relativePath>parent/pom.xml</relativePath>
</parent>
<modules>
  <module>parent</module>
  <module>child1</module>
  <module>child2</module>
</modules>

Both the maven release plugin and the eclipse IDE were happy with this structure. It was flat enough for eclipse and hierarchical enough for the maven release plugin.

Note: After experiencing and resolving this problem first hand I later discovered that the issue has already been reported and discussed here and mentioned at the very bottom of the maven eclipse plugin page. But I still cannot find any mention of this limitation on the maven release plugin page itself. I suspect that this is a well known issue in the maven community. If anyone is aware of any fixes or better solutions, please let me know. Interestingly also the title of this issue suggests that the problem has been fixed but the actual contents therein state otherwise.

Sample POM snippets – Posted on 22 Aug 2011 by request

workspace/pom.xml (The top level root POM)

  <parent> 
    <groupId>maven.demo</groupId> 
    <artifactId>parent</artifactId> 
    <version>1.0.0-SNAPSHOT</version>
    <relativePath>parent/pom.xml</relativePath>
  </parent> 

  <groupId>maven.demo</groupId>
  <artifactId>root</artifactId>
  <version>1.0.0-SNAPSHOT</version>
  <packaging>pom</packaging>

  <modules>
    <module>parent</module>
    <module>child1</module>
    <module>child2</module>
  </modules>

workspace/parent/pom.xml (The parent POM)

  <groupId>maven.demo</groupId>
  <artifactId>parent</artifactId>
  <version>1.0.0-SNAPSHOT</version>
  <packaging>pom</packaging>

workspace/child1/pom.xml (The child1 POM)

  <parent> 
    <groupId>maven.demo</groupId> 
    <artifactId>parent</artifactId> 
    <version>1.0.0-SNAPSHOT</version>
    <relativePath>../parent/pom.xml</relativePath>
  </parent> 

  <groupId>maven.demo</groupId>
  <artifactId>child1</artifactId>
  <version>1.0.0-SNAPSHOT</version>
  <packaging>jar</packaging>

workspace/child2/pom.xml (The child2 POM)

  <parent> 
    <groupId>maven.demo</groupId> 
    <artifactId>parent</artifactId> 
    <version>1.0.0-SNAPSHOT</version>
    <relativePath>../parent/pom.xml</relativePath>
  </parent> 

  <groupId>maven.demo</groupId>  
  <artifactId>child2</artifactId>
  <version>1.0.0-SNAPSHOT</version>
  <packaging>war</packaging>