Macros4Cuke
===========

_Add macros to your Cucumber scenarios._  
[Homepage](https://github.com/famished-tiger/Macros4Cuke)

__Macros4Cuke__ is a lightweight library that adds a macro facility your Cucumber scenarios.  
  With it, you can create any new step that replaces a sequence of lower-level steps.
  All this can be done directly in your feature files without programming step definitions.
 
### Highlights ###
* Works with out-of-the-box Cucumber
* Simple installation and setup (no programming required),
* Substep sequence can be of arbitrary length,
* Macro-steps may have data arguments,
* Data values can be passed to the sub-steps.

## A quick example ##
Here is a macro-step example taken from our demo files:  
```cucumber
  Given I define the step "When I [enter my userid <userid> and password <password>]" to mean:  
  """  
  Given I landed in the homepage  
  When I click "Sign in"  
  And I fill in "Username" with "<userid>"  
  And I fill in "Password" with "<password>"  
  And I click "Submit"  
  """  
```

Notice how the arguments _userid_ and _password_ are enclosed between chevrons (angle brackets) <...>.


That macro-step can then be used in a scenario like this:  
```cucumber 
  When I [enter my userid "jdoe" and password "hello-world"]
```

Once it is executing, the macro-step as the same effect as:  
```cucumber 
  Given I landed in the homepage  
  When I click "Sign in"  
  And I fill in "Username" with "jdoe"  
  And I fill in "Password" with "hello-world"  
  And I click "Submit"  
  """  
```

In other words, this sequence of 5 steps can be replaced by just one.
Macros4Cuke not only helps in getting rid of the repeated step sequences,
 it allows the feature writers to create themselves higher-level steps
 that are closer to the business logic.  

See also the working examples in the ```features/``` folder.

## Setup ##
### Installation ###
To install the macros4cuke gem:
```bash  
$[sudo] gem install macros4cuke
```

### Setting up your Cucumber project ####
  
* Step 1: Add support for macros in your Cucumber project    
  
```ruby
# /features/support/env.rb
# Add the two next lines
require 'macros4cuke'  
World(Macros4Cuke::MacroStepSupport)
```  
  
* Step 2: Import the macro-management steps  
In your `/features/step_definitions/` folder:  
  - Create a Ruby file (say, 'use\_macro\_steps.rb') with the following line:  
  
```ruby  
require 'macros4cuke/../macro_steps'
```  
  
That's it! Now you can start writing macros in your Cucumber project.


## Getting started ##
Working with a macro-step is a two-stages process:  
1. Defining a new macro-step; and,  
2. Using that macro-step in a scenario.

Let's begin by taking a closer look at the definition part.
### Defining a macro-step ###
To create a macro-step, you'll need to use a _defining_ step bundled with Macros4Cuke.
It is a rather unusual Cucumber step in the sense that its sole purpose is to build another step!  
The defining step follows the general pattern:
```cucumber
  Given I define the step "When I [some phrase]" to mean:  
  """  
  # A sequence of sub-steps comes here
  """  
```

The defining step has two key components:  
1. The _quoted sentence_ ```"When I [some phrase]"```. That part
 specifies the syntax of your future macro-step.  
2. The multiline text enclosed between the triple quotes (""") that immediately follows the
 the defining step. It is the place where the sub-steps are listed.  

These two components are detailed now.


#### Specifying the syntax of a macro-step ####
As just mentioned earlier, the __quoted sentence__ determines the syntax of the new macro-step.
Its syntax is more or less free:  
- The text outside the square brackets follows a fixed pattern. In other words,
 the quoted sentence MUST always start as follows: ```"When I [...```. Notice however,
 that the Given, Then keywords are also allowed.  
- The text delimited by the square brackets [...], is called the __phrase__.  

A few remarks about the __phrase__ part:  
- It must be unique. In other words, it is not possible to create another
  macro-step with the same phrase. In fact, Macros4Cuke uses the phrase internally as a mean to identify/name
  a macro-step.  
- It may have one or more arguments.
Besides that, the text inside the phrase can be arbitrary (well, almost).

A phrase can be without argument as in:  
```cucumber
  # A phrase without argument
  [enter my credentials]
```
  
Alternatively, a phrase can have one or more arguments enclosed between chevrons <...>.
For instance, the next first phrase has two arguments, the second has three arguments:  
```cucumber
  [enter my <userid> and <password>]
  [travel from <origin> to <destination> via <waypoint>]
```

Each argument (variable) is enclosed between <...> chevrons. In our last example,
the argument names are: _origin_ and _destination_. Notice that _origin_ and _destination_ are
 variable names that will take a value (if any) when the step is invoked _(more on this later)_.
 

#### Specifying the sub-steps of a macro-step ####
The sub-steps are placed in a Gherkin multiline text, that is, a text that is enclosed between 
 triple quotes ("""). In the next example,  
```cucumber 
  Given I define the step "When I [enter my credentials]" to mean:  
  """  
  Given I landed in the homepage   
  And I fill in "Username" with "tweedledum"  
  And I fill in "Password" with "tweedledee"  
  And I click "Sign in"  
  """  
```  
  
the text between triple quotes enumerates the sub-steps associated with the macro-step.  
 A pleasing aspect is the familiar syntax the sub-steps have: they closely look to genuine steps of a scenario.  
Sub-steps can also have macro arguments. 
 For instance, the previous step sequence could have two arguments called _userid_ and _password_:  
```cucumber  
  """  
  Given I landed in the homepage   
  And I fill in "Username" with "<userid>"  
  And I fill in "Password" with "<password>"  
  And I click "Sign in"  
  """  
``` 

### Using (invoking) a macro-step ###
A macro-step can only be invoked after its definition has been read by Cucumber.  
The syntax rules for using a given macro-step in a scenario are pretty straightforward:  
- Follow closely the syntax of the _quoted sentence_ in the macro definition.  
- Replace every \<argument\> in the _phrase_ by its actual value between quotes.  

#### Example 1: ####
Consider the following macro-step definition:  
```cucumber
  Given I define the step "When I [log in as <userid>]" to mean: 
  """
  # Sub-steps come here...
  """
```

Its quoted sentence is ```"When I [log in as <userid>]"```, therefore
 the macro-step can be invoked in a scenario like this:  
```cucumber
  Given I do this ...
  When I [log in as "jdoe"]
  And I do that...
```  

#### Example 2: ####
Here is another -partial- macro-step definition:  
```cucumber
  Given I define the step "When I [travel from <origin> to <destination> via <stop>]" to mean: 
  """
  # Sub-steps come here...
  """
```

This macro-step can occur in a scenario as:  
```cucumber
  When I [travel from "San Francisco" to "New-York" via "Las Vegas"]
```

The actual values for the arguments _origin_, _destination_ and _stop_ are
respectively San Francisco, New-York and Las Vegas.


### Passing argument data via a table  ###
Passing more than three arguments in the phrase becomes problematic for readability reasons.
 One ends up with lengthy and clumsy steps.  
Therefore __Macros4Cuke__ has an alternative way to pass data values via a Gherkin table.  
To enable this mechanism for a given macro, ensure that in its definition the quoted sentence ends with
a terminating colon (:) character.

The next example is based on one of the demo feature files:  
```cucumber
  # Next step has a colon ':'  after the ']': data can be passed with a table
  Given I define the step "When I [enter my address as follows]:" to mean:
  """
  When I fill in firstname with "<firstname>"  
  And I fill in lastname with  "<lastname>"  
  And I fill in street with "<street_address>"  
  And I fill in postcode with "<postcode>"  
  And I fill in locality with "<city>"  
  And I fill in country with "<country>"  
  """
```

This step can be used like this:
```cucumber
  When I [enter my address as follows]:"  
  |lastname|Doe|  
  |firstname|John|  
  |street_address| Main Street, 22|  
  |city| Old White Castle|  
  |postcode|JK345|  
```
  
Here are few observations worth noticing:   
- The data table has two columns.  
- Each row is of the form: |argument name| actual value|. For instance, the argument _street_address_ takes
the value "Main Street, 22".  
- Data rows don't have to follow strictly the order of the arguments in the sub-step sequence. 

## Naming macro-step arguments ##
In line with most computer languages, Macros4Cuke accepts argument names containing alphanumeric characters and 
underscores.  
In fact, the only characters that are not allowed in argument names are the following punctuation or delimiting
signs:  
__\!"'\#$%\&\*\+\-/,\.\:\;\=\?\(\)\<\>\[\]\{\}\\\^\`\|\~__


## With great power comes great responsibility. ##
_Stan Lee_  

Our experience is that macro-steps change deeply the way one designs and writes feature files.  
Macro-steps are most useful in UI-testing (e.g. with tools like Capybara) because they help to close
 the gap between the user's intent and the low-level user interface actions.   
In addition __Macros4Cuke__ allows advanced users to craft their own steps without having to program step definitions.
This last argument becomes important in the context of user acceptance testing, a domain where the assumption that
 every tester is also Rubyist is -alas!- far from the truth.

 
Macros with Cucumber is highly debated topic, so it is always wise to know what other people say about it:  
[Support for Macros] (https://github.com/cucumber/gherkin/issues/178)  
[Substeps - macro request for the nth time] (http://grokbase.com/t/gg/cukes/133ey063b8/cucumber-substeps-macro-request-for-the-nth-time)


Copyright
---------
Copyright (c) 2013, Dimitri Geshef. Macros4Cuke is released under the MIT License see [LICENSE.txt](https://github.com/famished-tiger/Macros4Cuke/blob/master/LICENSE.txt) for details.