Evaluate Browser params

[ka3de]

Look through the existing browser configurable parameters and evaluate:

1. Which will be useful for the user
2. Which will work locally and also when connected to a remote browser.
3. What is the best mean through which specify the parameter (env variable, test script options).

Related: #857

[ka3de]

Browser parameters have been reevaluated with the following criteria:

• Only the options that have an actual effect in the test execution will be supported as test script options. These are options that can have an impact in the correctness of the test and therefore make sense that are "hardcoded" in the actual script definition.
• Every option that is "circumstantial" / "environment related" will be supported as environment variable only.
• Every option that has low value or is currently unimplemented will be removed and not supported by now.

Following this criteria, the proposed browser options modifications are:

Option	Description	Supported
slowMo	Slow down input actions and navigation by the specified time e.g. 500ms.	script
timeout	Default timeout to use for various actions and navigation.	script
headless	Show browser GUI or not.	env
debug	All CDP messages and internal fine grained logs will be logged if set to true.	env
args	Extra command line arguments to include when launching browser process.	env
ignoreDefaultArgs	Ignore any of the default arguments included when launching the browser process.	env
executablePath	Override search for browser executable in favor of specified absolute path.	env
cdpWSURL	Specifies the CDP WS URL to connect to. If set, k6 browser will try to connect to this WS instead of launching a new browser.	env
devtools	Open up developer tools in the browser by default.	remove
env	Environment variables to set before launching the browser process.	remove
proxy	Specify to set browser's proxy configuration.	remove

These decisions apply for the current status of k6 browser and can be changed in the future. Especially "promotions" following the path: not supported -> env supported -> script supported.

CC: @ankur22 , @mdcruz, @inancgumus, @andrewslotin.

[mdcruz]

For reference, this is how Playwright defines Global setup and teardown https://playwright.dev/docs/test-global-setup-teardown

[ka3de]

Based on discussions from #857 , the table defined in the previous comment requires some modifications. Specifically in relation with the timeout and slowMo options:

timeout

Currently the timeout option defined at the browser level applied to two different functionalities:

• Defined the TO to apply for some "browser initialization" actions, such as TO when launching the browser instnace.
• Defined the default navigation TO. This one could be overwritten at the browserContext and page levels.

We believe that his double purpose is wrong, as a the use cases are quite different and a single value for both does not make sense. At the same time, though, we still believe that defining a TO for the browser initialization actions provides value and is required. Taking this into account our decisions have been:

• The browser level timeout option will apply only for the browser initialization actions. Not for the default navigation TO.
• The browser level timeout option will be moved to be defined as an ENV variable, instead of being defined at the script level.
• The default navigation TO will be set by our own implementation with an initial sensible value. This value will be able to be overwritten at the browserContext and page levels, as it's currently possible.

slowMo

• slowMo won't be supported at the browser level, and instead will eventually be moved to the browserContext level.

Final definition

Option	Description	Supported
timeout	Default timeout to use for various browser initialization actions and navigation.	env
headless	Show browser GUI or not.	env
debug	All CDP messages and internal fine grained logs will be logged if set to true.	env
args	Extra command line arguments to include when launching browser process.	env
ignoreDefaultArgs	Ignore any of the default arguments included when launching the browser process.	env
executablePath	Override search for browser executable in favor of specified absolute path.	env
cdpWSURL	Specifies the CDP WS URL to connect to. If set, k6 browser will try to connect to this WS instead of launching a new browser.	env
slowMo	Slow down input actions and navigation by the specified time e.g. 500ms.	removed [*]
devtools	Open up developer tools in the browser by default.	remove
env	Environment variables to set before launching the browser process.	remove
proxy	Specify to set browser's proxy configuration.	remove

[*] Eventuallly moved to browserContext level (see #863).