Launch Settings

What a plugin learns about a browser before it starts, and what it may change. The set checks every plugin against a LaunchContext; before_launch gets the browser’s LaunchSettings, which the host turns into the engine’s own options after every plugin has run. Items are in seleniumbase_rs_plugin, defined in crates/seleniumbase-rs-plugin/src/lib.rs.

LaunchContext#

struct seleniumbase_rs_plugin::LaunchContext

#[derive(Clone, Copy, Debug, PartialEq, Eq)]pub struct LaunchContext {    pub engine: Engine,    pub family: BrowserFamily,    pub headless: bool,    pub connecting: bool,}

What the set checks a plugin against before a browser starts, in PluginSet::check and check_with. It is not #[non_exhaustive], so a test builds one with a struct literal.

What the hosts of seleniumbase-rs pass:

A launch checks the set twice, before and after before_launch, because a plugin may change what another was checked against, such as headless mode.

LaunchSettings#

struct non_exhaustive seleniumbase_rs_plugin::LaunchSettings

#[derive(Clone, Debug, Default, PartialEq)]#[non_exhaustive]pub struct LaunchSettings {    pub args: Vec<String>,    pub prefs: serde_json::Map<String, Value>,    pub extensions: Vec<PathBuf>,    pub proxy: Option<String>,    pub headless: bool,    pub host_resolver_rules: Vec<String>,    pub webrtc_policy: Option<WebRtcPolicy>,    pub disable_features: Vec<String>,    pub enable_features: Vec<String>,    pub disable_quic: bool,    // private: profile: ProfileView}

The start-up settings a plugin may change in before_launch. After each plugin, PluginSet::before_launch compares the settings with what they were and refuses a change the plugin may not make, as PluginError::Capability or PluginError::Sealed. Outside the crate, start from LaunchSettings::default() and assign the fields.

What each engine fills in and applies#

A refusal on Firefox or Safari is SeleniumBaseError::Plugin (a plugin's before_launch asked for what Firefox cannot do here: ...). The guide has the details per browser: The WebDriver engine.

LaunchSettings::profile#

fn seleniumbase_rs_plugin::LaunchSettings::profile

#[must_use]pub fn profile(&self) -> &ProfileView

The hosts show ProfileView::Persistent(folder) when the launch names a profile folder (user_data_dir), and ProfileView::Ephemeral otherwise.

LaunchSettings::set_profile#

fn seleniumbase_rs_plugin::LaunchSettings::set_profile

pub fn set_profile(&mut self, profile: ProfileView)

For the host, before the plugins run. A plugin that calls it is refused after its hook: PluginError::Capability on profile, the profile is read-only for plugins.

ProfileView#

enum non_exhaustive seleniumbase_rs_plugin::ProfileView

#[derive(Clone, Debug, Default, PartialEq, Eq)]#[non_exhaustive]pub enum ProfileView {    #[default]    Ephemeral,    Persistent(PathBuf),}

Engine#

enum non_exhaustive seleniumbase_rs_plugin::Engine

#[derive(Clone, Copy, Debug, PartialEq, Eq)]#[non_exhaustive]pub enum Engine {    Cdp,    WebDriver,}

Which of seleniumbase-rs’s engines runs the browser. A plugin reads it from LaunchContext::engine, BrowserHandle::engine and PageHandle::engine.

BrowserFamily#

enum non_exhaustive seleniumbase_rs_plugin::BrowserFamily

#[derive(Clone, Copy, Debug, PartialEq, Eq)]#[non_exhaustive]pub enum BrowserFamily {    Chromium,    Firefox,    Safari,    Embedded,}

The family of the browser a plugin runs with.

The WebDriver engine refuses plugins for Internet Explorer, which is none of these families, with SeleniumBaseError::Plugin.

WebRtcPolicy#

enum non_exhaustive seleniumbase_rs_plugin::WebRtcPolicy

#[derive(Clone, Copy, Debug, PartialEq, Eq)]#[non_exhaustive]pub enum WebRtcPolicy {    Default,    DefaultPublicInterfaceOnly,    DefaultPublicAndPrivateInterfaces,    DisableNonProxiedUdp,}

Chrome’s WebRTC IP-handling policies, the value of LaunchSettings::webrtc_policy. Both engines turn it into one --force-webrtc-ip-handling-policy switch.

A policy added to the API later, which this version of seleniumbase-rs cannot apply, is SeleniumBaseError::InvalidConfig.