take_screenshot.py

import os
import shutil
import imagecompare
'''module for taking a screenshot and comparing it'''


def take_screenshot(browser, filename):
    '''Takes a screenshot of the requested webpage
    :param browser: an instance of a selenium webdriver
    :param filename: the filename to save as
    :return: true if image is the same, false if its different
    '''

    # if it doesn't exist make the outputs directory
    if os.path.exists("outputs") is not True:
        os.mkdir("outputs")

    if os.path.exists("outputs/screenshots") is not True:
        os.mkdir("outputs/screenshots")

    browser.save_screenshot("outputs/screenshots/" + filename)
    is_different = False
    # compare with the previous screenshot (if it exists)
    if os.path.isfile("outputs/old_screenshots/" + filename) is True:
        print("old image exists, comparing ", "outputs/screenshots/" +
              filename, "with outputs/old_screenshots/" + filename)

        is_different = imagecompare.compare_image("outputs/screenshots/"
                                                  + filename,
                                                  "outputs/old_screenshots/"
                                                  + filename,
                                                  "outputs/comparison-"
                                                  + filename,
                                                  "outputs/mask-" + filename)
        if is_different is True:
            print(filename, "has changed")
            status_file = open("outputs/" + filename + ".status", "w")
            status_file.write("changed")
            status_file.close()
        else:
            print(filename, "hasn't changed")
            # delete the mask and comparison image if they exist
            status_file = open("outputs/" + filename + ".status", "w")
            status_file.write("unchanged")
            status_file.close()

        # copy the image for the report
        print("copying outputs/old_screenshots/" + filename,
              "to outputs/report-" + filename)
        shutil.copyfile("outputs/old_screenshots/" + filename,
                        "outputs/report-" + filename)

    else:
        print("old file doesn't exist")

    # if it doesn't exist make a directory for screenshots
    if os.path.exists("outputs/old_screenshots") is not True:
        os.mkdir("outputs/old_screenshots")

    # copy the image
    shutil.copyfile("outputs/screenshots/"+filename,
                    "outputs/old_screenshots/"+filename)
    return is_different