B2G/QA/Automation/Style Guide/Python Script Style

Python Script Style Guide

Naming

• Module names should be called test_ and then behavioral areas.

   test_search.py

• Test method names should always show the intent of the test case.

# Good
def test_that_advanced_search_does_not_find_item(self):

# Bad
def test_advanced_search(self):

File Headers

• Each file should have a completed copy of the MPL2 license block, immediately followed by an empty line.
• Each file should pass PEP8 except for line length, see below.

# Good
def method(self, parameter) 

# Bad
def method(self,parameter)

• Lines should try not to have more than 100 characters.
• Docstrings should conform to PEP0257 and should be on a single line wherever possible.

# Good
def click_login():
"""Clicks the login link."""

# Bad
def click_login():
"""
Clicks the login link.
"""

Where not possible, the first line should be a summary.

# Good
def login():
"""Logs in.

Clicks the login link and then waits for the home page to load.

"""

# Bad
def login():
"""Logs in.
Clicks the login link and then waits for the home page to load."""

• Indenting should be a soft tab (4 spaces) as common with in Python. Do not mix tabs and spaces!
• There should be no whitespace at the end of the file (as per PEP8).
• Comments should be on the line above. Remember to update comments when changing code so that code matches the comments.
• Comments should be used carefully. Try not to put comments that don't provide any additional value
• Class names should be in Pascal style as this is Python idiomatic.

# Good
class TestThisSite:
    
# Bad
class test_this_site:

Actions

• Methods that perform actions on the page should indicate the action in the method name.

# Good
def click_report_with_length(length)

# Bad
def report_length(length)

• Actions should wait for the appropriate action to complete. This could be an implicit or explicit wait. For example, clicking a login button might explicitly wait for a username field to be visible.

Use testvars.json <njpark>

Using test variable file when running gaiatest can avoid defining variables inside the script. The testvars template is located here.
Make sure to fill in the appropriate section if you're planning to use it, and supply the name and location of the .json file as the parameter to the gaiatest command with --testvars= option.

If you want to access the varable value defined in the .json file, you can do as the following example:

test_phone_number = self.testvars['remote_phone_number']

If you need to access the sub-variable, consider below example as well:

self.testvars['plivo']['auth_id'],
self.testvars['plivo']['auth_token'],
self.testvars['plivo']['phone_number']

Using high-level methods

TBD - jlorenzo

• In a test, make sure to only have steps that are high level (for instance: messages.send_an_sms_to_yourself() instead of detailing every single tap and click)

Avoid sleep() calls

TBD - njpark

Variable naming

TBD - jlorenzo

• Name your variables with units. For example: timeout_in_seconds, width_in_pixels
• Don't shorten variable names. A bad example: self.t_out_err_tim = 1000 instead of self.time_out_error_time

app.py and regions/helper.py

TBD - njpark

How to create filename strings

TBD - njpark http://mxr.mozilla.org/gaia/source/tests/python/gaia-ui-tests/gaiatest/apps/settings/app.py#296

Meaningful custom Assert() messages

TBD - njpark

https://bugzilla.mozilla.org/show_bug.cgi?id=1198449#c2

Clean up afterwards

TBD - njpark

Avoid code duplication

TBD - jlorenzo

• Use parameterized()
• Centralize workarounds

Simulate end-user check

TBD - jlorenzo

• Check what an end-user would check.
• Make sure manifest.ini is updated with right flags

Making test multi-locale

TBD - njpark

• we check the raw text in order to verify the input from the user (for instance a phone number put in the dialer, we verify it appears in the call log)
• we test the l10n-id for any string that comes from Gaia only (like an error message)

Be aware of outside consumers of ui-test

TBD - mwargers

• Be aware if you change the Gaia UI test API, that outside consumers (mtbf, etc) might get broken