SeleniumBase/help_docs/how_it_works.md

## [<img src="https://seleniumbase.io/img/logo6.png" title="SeleniumBase" width="32">](https://github.com/seleniumbase/SeleniumBase/) How SeleniumBase Works:

<a id="how_seleniumbase_works"></a>

At the core, SeleniumBase works by extending [pytest](https://docs.pytest.org/en/latest/) as a direct plugin. SeleniumBase automatically spins up web browsers for tests (using Selenium WebDriver), and then gives those tests access to the SeleniumBase libraries through the [BaseCase class](https://github.com/seleniumbase/SeleniumBase/blob/master/seleniumbase/fixtures/base_case.py). Tests are also given access to [SeleniumBase command-line arguments](https://github.com/seleniumbase/SeleniumBase/blob/master/help_docs/customizing_test_runs.md) and [SeleniumBase methods](https://github.com/seleniumbase/SeleniumBase/blob/master/help_docs/method_summary.md), which provide additional functionality.

(NOTE: pytest uses a feature called test discovery to automatically find and run Python methods that start with "``test_``" from the file that you specified on the command line.)

The most common way of using SeleniumBase is by inheriting BaseCase:

```python
from seleniumbase import BaseCase
```

Then have your test classes inherit BaseCase:

```python
class MyTestClass(BaseCase):
```

Here's what a full test might look like:

```python
from seleniumbase import BaseCase

class TestMFALogin(BaseCase):
    def test_mfa_login(self):
        self.open("https://seleniumbase.io/realworld/login")
        self.type("#username", "demo_user")
        self.type("#password", "secret_pass")
        self.enter_mfa_code("#totpcode", "GAXG2MTEOR3DMMDG")  # 6-digit
        self.assert_text("Welcome!", "h1")
        self.highlight("img#image1")  # A fancier assert_element() call
        self.click('a:contains("This Page")')
        self.save_screenshot_to_logs()  # In "./latest_logs/" folder.
        self.click_link("Sign out")  # Must be "a" tag. Not "button".
        self.assert_element('a:contains("Sign in")')
        self.assert_exact_text("You have been signed out!", "#top_message")
```

(See the example test, [my_first_test.py](https://github.com/seleniumbase/SeleniumBase/blob/master/examples/my_first_test.py), for reference.)

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For more ways of using SeleniumBase, see: <a href="https://seleniumbase.io/help_docs/syntax_formats/">SyntaxFormats</a>.