Logging Selenium commands

Getting information about Selenium execution.

Turning on logging is a valuable way to get extra information that might help you determine why you might be having a problem.

Getting a logger

Java logs are typically created per class. You can work with the default logger to work with all loggers. To filter out specific classes, see Filtering

Get the root logger:

    Logger.getLogger(SeleniumManager.class.getName()).setLevel(Level.SEVERE);
View full example on GitHub

Java Logging is not exactly straightforward, and if you are just looking for an easy way to look at the important Selenium logs, take a look at the Selenium Logger project

Python logs are typically created per module. You can match all submodules by referencing the top level module. So to work with all loggers in selenium module, you can do this:

import pytest
View full example on GitHub 
.NET does not currently have a Logging implementation

If you want to see as much debugging as possible in all the classes, you can turn on debugging globally in Ruby by setting $DEBUG = true.

For more fine-tuned control, Ruby Selenium created its own Logger class to wrap the default Logger class. This implementation provides some interesting additional features. Obtain the logger directly from the #loggerclass method on the Selenium::WebDriver module:

      logger = Selenium::WebDriver.logger
View full example on GitHub 
const logging = require('selenium-webdriver/lib/logging')
logger = logging.getLogger('webdriver')

Logger level

Logger level helps to filter out logs based on their severity.

Java has 7 logger levels: SEVERE, WARNING, INFO, CONFIG, FINE, FINER, and FINEST. The default is INFO.

You have to change both the level of the logger and the level of the handlers on the root logger:


    Logger localLogger = Logger.getLogger(this.getClass().getName());
    localLogger.warning("this is a warning");
    localLogger.info("this is useful information");
View full example on GitHub

Python has 6 logger levels: CRITICAL, ERROR, WARNING, INFO, DEBUG, and NOTSET. The default is WARNING

To change the level of the logger:

View full example on GitHub

Things get complicated when you use PyTest, though. By default, PyTest hides logging unless the test fails. You need to set 3 things to get PyTest to display logs on passing tests.

To always output logs with PyTest you need to run with additional arguments. First, -s to prevent PyTest from capturing the console. Second, -p no:logging, which allows you to override the default PyTest logging settings so logs can be displayed regardless of errors.

So you need to set these flags in your IDE, or run PyTest on command line like:

pytest -s -p no:logging

Finally, since you turned off logging in the arguments above, you now need to add configuration to turn it back on:

logging.basicConfig(level=logging.WARN)

.NET does not currently have a Logging implementation

Ruby logger has 5 logger levels: :debug, :info, :warn, :error, :fatal. As of Selenium v4.9.1, The default is :info.

To change the level of the logger:

      logger.level = :debug
View full example on GitHub

JavaScript has 9 logger levels: OFF, SEVERE, WARNING, INFO, DEBUG, FINE, FINER, FINEST, ALL. The default is OFF.

To change the level of the logger:

logger.setLevel(logging.Level.INFO)

Actionable items

Things are logged as warnings if they are something the user needs to take action on. This is often used for deprecations. For various reasons, Selenium project does not follow standard Semantic Versioning practices. Our policy is to mark things as deprecated for 3 releases and then remove them, so deprecations may be logged as warnings.

Java logs actionable content at logger level WARN

Example:

May 08, 2023 9:23:38 PM dev.selenium.troubleshooting.LoggingTest logging
WARNING: this is a warning

Python logs actionable content at logger level — WARNING Details about deprecations are logged at this level.

Example:

WARNING  selenium:test_logging.py:23 this is a warning

.NET does not currently have a Logging implementation

Ruby logs actionable content at logger level — :warn. Details about deprecations are logged at this level.

For example:

2023-05-08 20:53:13 WARN Selenium [:example_id] this is a warning

Because these items can get annoying, we’ve provided an easy way to turn them off, see filtering section below.

Useful information

This is the default level where Selenium logs things that users should be aware of but do not need to take actions on. This might reference a new method or direct users to more information about something

Java logs useful information at logger level INFO

Example:

May 08, 2023 9:23:38 PM dev.selenium.troubleshooting.LoggingTest logging
INFO: this is useful information

Python logs useful information at logger level — INFO

Example:

INFO     selenium:test_logging.py:22 this is useful information

.NET does not currently have a Logging implementation

Ruby logs useful information at logger level — :info.

Example:

2023-05-08 20:53:13 INFO Selenium [:example_id] this is useful information

Logs useful information at level: INFO

Debugging Details

The debug log level is used for information that may be needed for diagnosing issues and troubleshooting problems.

Java logs most debug content at logger level FINE

Example:

May 08, 2023 9:23:38 PM dev.selenium.troubleshooting.LoggingTest logging
FINE: this is detailed debug information

Python logs debugging details at logger level — DEBUG

Example:

DEBUG    selenium:test_logging.py:24 this is detailed debug information

.NET does not currently have a Logging implementation

Ruby only provides one level for debugging, so all details are at logger level — :debug.

Example:

2023-05-08 20:53:13 DEBUG Selenium [:example_id] this is detailed debug information

Logs debugging details at level: FINER and FINEST

Logger output

Logs can be displayed in the console or stored in a file. Different languages have different defaults.

By default all logs are sent to System.err. To direct output to a file, you need to add a handler:


    byte[] bytes = Files.readAllBytes(Paths.get("selenium.xml"));
View full example on GitHub

By default all logs are sent to sys.stderr. To direct output somewhere else, you need to add a handler with either a StreamHandler or a FileHandler:

    logger = logging.getLogger('selenium')
View full example on GitHub 
.NET does not currently have a Logging implementation

By default, logs are sent to the console in stdout.
To store the logs in a file:

      logger.output = file_name
View full example on GitHub

JavaScript does not currently support sending output to a file.

To send logs to console output:

logging.installConsoleHandler()

Logger filtering

Java logging is managed on a per class level, so instead of using the root logger (Logger.getLogger("")), set the level you want to use on a per-class basis:


    Assertions.assertTrue(fileContent.contains("this is a warning"));
View full example on GitHub
Because logging is managed by module, instead of working with just "selenium", you can specify different levels for different modules: 

    log_path = "selenium.log"
View full example on GitHub 
.NET does not currently have a Logging implementation

Ruby’s logger allows you to opt in (“allow”) or opt out (“ignore”) of log messages based on their IDs. Everything that Selenium logs includes an ID. You can also turn on or off all deprecation notices by using :deprecations.

These methods accept one or more symbols or an array of symbols:

      logger.ignore(:jwp_caps, :logger_info)
View full example on GitHub

or

      logger.allow(%i[selenium_manager example_id])
View full example on GitHub
最后修改 June 28, 2023: update logging example code and references (#1417)[deploy site] (8ac6031d33)