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2.4. Class based libraries

Goal

  • Create a new class based library named JSONLibrary with a keyword named Parse JSON File. This keyword should open and parse the content of the given JSON file and return the parsed data.
  • Make sure that the JSONLibrary available to every test case.
  • Modify the test case named Get Exam Results to use JSONLibrary and Parse JSON File keyword.

Solution

Hints

Test libraries can be implemented as Python modules and Python or Java classes.

Click here to learn more about creating test libraries.

Solution: tests/libraries/JSONLibrary.py
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from robot.api.deco import keyword
from robot.api.deco import library
import json


@library(scope='GLOBAL', version='1.0')
class JSONLibrary():
    """Library which contains keywords to work with JSON files."""

    @keyword(tags=['json'], types={'json_file': str})
    def parse_json_file(self, json_file):
        """Returns the parsed ``json_file`` as a dictionary.

        Example:
        | &{parsed_json}= | Parse JSON File | exam_results.json |
        =>
        | ${parsed_json}= {'Jane Doe': {'math': '90%', 'physics': '85%'}}
        """
        with open(json_file, 'r') as json_content:
            return json.load(json_content)
Solution: tests/02-classroom/02-exams.robot
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*** Test Cases ***
Get Exam Results
    &{results}=    Parse JSON File    ${EXAM_RESULTS_JSON}
    Log To Console    ${\n}    no_newline=True
    FOR    ${student}    ${results}    IN    &{results}
        Log To Console    ${student}: ${results}
    END

*** Settings ***
Library    JSONLibrary

*** Variables ***
${EXAM_RESULTS_JSON}    ${CURDIR}${/}test_data${/}exam_results.json

Results

To be able to import JSONLibrary without defining the whole path to the file, you need to set its location with --pythonpath parameter.

Inside the tests folder, execute the following command to execute 02-Exams suite.

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robot --pythonpath libraries --suite 02-Exams .

You can check the generated log.html file to see how your test cases worked.

Last update: June 22, 2020