Mastering Robot Framework Variables – A Comprehensive Guide for Test Automation Engineers

Understanding Robot Framework Variables

In Robot Framework, variables play a crucial role in test automation. They allow us to store and retrieve values, making our tests dynamic and flexible. There are three types of variables in Robot Framework: Scalar Variables, List Variables, and Dictionary Variables. Let’s explore each type in detail.

Scalar Variables

Scalar variables are used to store single values, such as strings, numbers, or booleans. They are the simplest form of variables in Robot Framework. Scalar variables can be used to define test data, configuration settings, and other fixed values.

Here are some examples of scalar variables:

${name}             John Doe ${age}              27 ${is_adult}         ${True} 

Scalar variables can be accessed and used in test cases and keywords by enclosing them in curly brackets, like ${variable_name}.

List Variables

List variables are used to store a collection of values. They are enclosed in square brackets and the individual values are separated by a pipe (|) character. List variables allow us to work with multiple values as a group, enabling us to perform iterations and validations efficiently.

Here are some examples of list variables:

@{colors}           Red | Green | Blue @{numbers}          1 | 2 | 3 | 4 | 5 

List variables can be accessed and used in test cases and keywords using the same syntax as scalar variables. We can retrieve individual items from a list using indexing, where the index starts from 0.

Dictionary Variables

Dictionary variables are used to store key-value pairs. They are enclosed in curly brackets, where keys and values are separated by a colon (:), and each key-value pair is separated by a pipe (|) character. Dictionary variables allow us to work with structured data and provide a convenient way to define and manipulate complex objects.

Here are some examples of dictionary variables:

&{person}           name: John Doe | age: 27 | gender: Male &{config}           browser: Chrome | timeout: 10 | headless: ${True} 

Similar to scalar and list variables, dictionary variables can be accessed and used in test cases and keywords using the same syntax. To retrieve a specific value from a dictionary, we can use the key name.

Declaring and Assigning Variables in Robot Framework

Now that we understand the different types of variables in Robot Framework, let’s explore how to declare and assign values to them.

Scalar Variables

To declare a scalar variable, we can use the Set Variable keyword. This keyword allows us to assign a value to a scalar variable.

For example, let’s consider a scenario where we need to store a person’s name:

*** Test Cases *** Example Test Case Set Variable    ${name}    John Doe Log    The name is: ${name} 

In the above example, the Set Variable keyword is used to assign the value “John Doe” to the ${name} variable. Subsequently, the Log keyword is used to print the value of ${name}.

In some cases, we may need to set a global variable that can be accessed across multiple test cases. We can achieve this using the Set Global Variable keyword.

List Variables

To initialize a list variable, we enclose the values within square brackets and separate them using the pipe (|) character.

For example, let’s consider a scenario where we need to store a list of colors:

*** Test Cases *** Example Test Case @{colors}    Create List    Red    Green    Blue Log    The colors are: @{colors} 

In the above example, the Create List keyword is used to initialize the @{colors} list variable with the values Red, Green, and Blue. Subsequently, the Log keyword is used to print the values of @{colors}.

Once a list variable is initialized, we can append new items using the Append To List keyword and remove items using the Remove From List keyword.

Dictionary Variables

To initialize a dictionary variable, we enclose the key-value pairs within curly brackets, where each key-value pair is separated by a pipe (|) character.

For example, let’s consider a scenario where we need to store a person’s details:

*** Test Cases *** Example Test Case &{person}    Create Dictionary    name: John Doe    age: 27    gender: Male Log    The person is: &{person} 

In the above example, the Create Dictionary keyword is used to initialize the &{person} dictionary variable with the key-value pairs name: John Doe, age: 27, and gender: Male. Subsequently, the Log keyword is used to print the values of &{person}.

We can update the values of a dictionary variable using the Set To Dictionary keyword, which allows us to modify or add new key-value pairs.

Accessing and Using Variables in Robot Framework

Once variables are declared and assigned values, we can access and use them in test cases and keywords.

Scalar Variables

Scalar variables can be used directly in test steps and keywords by enclosing them in curly brackets, like ${variable_name}.

For example, let’s consider a scenario where we want to use a scalar variable to navigate to a specific URL:

*** Test Cases *** Example Test Case Set Variable    ${url}    www.example.com Go To    ${url} 

In the above example, the ${url} scalar variable is assigned the value “http://www.example.com” using the Set Variable keyword. The Go To keyword is then used to navigate to the URL stored in the ${url} variable.

We can also use scalar variables in keywords by passing them as arguments.

List Variables

List variables can be accessed and used in a similar way to scalar variables. We can retrieve individual items from a list using indexing and perform operations on the list.

For example, let’s consider a scenario where we want to verify the presence of certain items in a list:

*** Test Cases *** Example Test Case @{fruits}    Create List    Apple    Banana    Orange Run Keyword If    'Apple' in @{fruits}    Log    Apple is present Remove From List    ${fruits}    Orange Log    ${fruits} 

In the above example, the Run Keyword If keyword is used to check if the item ‘Apple’ is present in the @{fruits} list. If it is present, the Log keyword is used to print a message. The Remove From List keyword is then used to remove the item ‘Orange’ from the list, and the updated list is printed using the Log keyword.

Dictionary Variables

Dictionary variables can be accessed and used similarly to scalar and list variables. We can retrieve specific values using the key name and perform manipulations on the dictionary.

For example, let’s consider a scenario where we want to retrieve a person’s name and age from a dictionary:

*** Test Cases *** Example Test Case &{person}    Create Dictionary    name: John Doe    age: 27    gender: Male Log    The person's name is: &{person}[name] Log    The person's age is: &{person}[age] 

In the above example, the Log keyword is used to retrieve and print the values of the ‘name’ and ‘age’ keys from the &{person} dictionary.

We can also update the values of a dictionary variable using the Set To Dictionary keyword.

Best Practices for Using Variables in Robot Framework

When working with variables in Robot Framework, it is important to follow certain best practices to ensure clarity, reusability, and maintainability of our test automation code.

Naming conventions for variables

Using descriptive names for variables can greatly improve code readability. It is advisable to use meaningful names that reflect the purpose or content of the variable.

For example, instead of using a variable name like ${var1}, a more descriptive name like ${guest_name} would be more meaningful.

Variable scope and visibility

Understanding variable scope and visibility is crucial to avoid conflicts and unintended side effects. Global variables can be accessed across multiple test cases, while local variables are limited to a specific test case or keyword.

It is important to define variables in the appropriate scope to avoid naming conflicts and unintended data modifications.

Reusability and modularity with variables

Variables allow us to create reusable and modular test cases and keywords. By using variables, we can easily modify test data or configuration settings without changing the underlying test steps.

We can encapsulate common operations into reusable keywords that accept variables as arguments, making our tests more flexible and adaptable.

Conclusion

In this blog post, we explored the various types of variables in Robot Framework and learned how to declare, assign, access, and use them effectively. Variables are powerful tools that enable us to make our tests dynamic, flexible, and reusable. By mastering variables in Robot Framework, we enhance our test automation capabilities and improve the efficiency and effectiveness of our test suites.

So, whether you are a beginner or an experienced user of Robot Framework, it is highly recommended to incorporate the usage of variables into your test automation workflow. Understanding and leveraging variables will undoubtedly take your automation efforts to the next level.