Add browser_launch_opts config option

README.md

@@ -153,6 +153,28 @@ defmodule DebuggingFeatureTest do
 end
 ```
 
+### Browser Launch Options
+
+Pass additional arguments to the browser via `browser_launch_opts`. This is useful for
+testing features that require specific browser flags, like fake media streams for
+audio/video capture tests:
+
+```elixir
+# config/test.exs
+config :phoenix_test,
+  playwright: [
+    browser_launch_opts: [
+      args: [
+        "--use-fake-ui-for-media-stream",
+        "--use-fake-device-for-media-stream"
+      ]
+    ]
+  ]
+```
+
+See [Playwright's browserType.launch() docs](https://playwright.dev/docs/api/class-browsertype#browser-type-launch)
+for all available options.
+
 
 ## Remote Playwright Server
 

lib/phoenix_test/playwright/config.ex

@@ -12,6 +12,14 @@ browser_opts = [
     type: {:in, browsers},
     type_doc: "`#{Enum.map_join(browsers, " | ", &":#{&1}")}`"
   ],
+  browser_launch_opts: [
+    default: [],
+    type: {:or, [:map, :keyword_list]},
+    doc: """
+    Additional arguments passed to Playwright [browserType.launch](https://playwright.dev/docs/api/class-browsertype#browser-type-launch).
+    E.g. `[args: ["--use-fake-ui-for-media-stream", "--use-fake-device-for-media-stream"]]`.
+    """
+  ],
   browser_launch_timeout: [
     default: to_timeout(second: 4),
     type: :non_neg_integer
@@ -60,6 +68,7 @@ schema_opts = [
     """
   ],
   browser: browser_opts[:browser],
+  browser_launch_opts: browser_opts[:browser_launch_opts],
   browser_context_opts: [
     default: [],
     type: {:or, [:map, :keyword_list]},
@@ -172,9 +181,9 @@ schema_opts = [
 
 schema = NimbleOptions.new!(schema_opts)
 
-setup_all_keys = ~w(browser_pool browser browser_launch_timeout executable_path headless slow_mo)a
+setup_all_keys = ~w(browser_pool browser browser_launch_opts browser_launch_timeout executable_path headless slow_mo)a
 setup_keys = ~w(accept_dialogs ecto_sandbox_stop_owner_delay screenshot trace browser_context_opts browser_page_opts)a
-merge_global_into_browser_pool_keys = ~w(browser browser_launch_timeout headless slow_mo)a
+merge_global_into_browser_pool_keys = ~w(browser browser_launch_opts browser_launch_timeout headless slow_mo)a
 
 defmodule PhoenixTest.Playwright.Config do
   @moduledoc """

lib/phoenix_test/playwright/internal/browser.ex

@@ -7,7 +7,9 @@ defmodule PhoenixTest.Playwright.Browser do
   def launch_browser!(config) do
     {launch_timeout, opts} = Keyword.pop!(config, :browser_launch_timeout)
     {browser, opts} = Keyword.pop!(opts, :browser)
+    {launch_opts, opts} = Keyword.pop(opts, :browser_launch_opts, [])
     opts = opts |> Keyword.put(:timeout, launch_timeout) |> Keyword.delete(:browser_pool)
+    opts = Keyword.merge(opts, launch_opts)
 
     case PlaywrightEx.launch_browser(browser, opts) do
       {:ok, browser} ->

test/phoenix_test/playwright/browser_launch_opts_test.exs

@@ -0,0 +1,18 @@
+defmodule PhoenixTest.Playwright.BrowserLaunchOptsTest do
+  @moduledoc """
+  Tests that browser_launch_opts are passed through to Playwright.
+  """
+
+  use PhoenixTest.Playwright.Case,
+    async: true,
+    browser_pool: false,
+    browser_launch_opts: [args: ["--disable-background-networking"]]
+
+  test "launches browser with custom launch opts", %{conn: conn} do
+    # Verifies that browser_launch_opts is accepted by the config and doesn't
+    # break browser launching. The args are passed through to Playwright.
+    conn
+    |> visit("/pw/live")
+    |> assert_has("h1")
+  end
+end

test/phoenix_test/playwright/config_test.exs

@@ -0,0 +1,26 @@
+defmodule PhoenixTest.Playwright.ConfigTest do
+  use ExUnit.Case, async: true
+
+  alias PhoenixTest.Playwright.Config
+
+  describe "browser_launch_opts" do
+    test "accepts keyword list" do
+      config = Config.validate!(browser_launch_opts: [args: ["--disable-gpu"]])
+      assert config[:browser_launch_opts] == [args: ["--disable-gpu"]]
+    end
+
+    test "accepts map" do
+      config = Config.validate!(browser_launch_opts: %{args: ["--disable-gpu"]})
+      assert config[:browser_launch_opts] == %{args: ["--disable-gpu"]}
+    end
+
+    test "defaults to empty list" do
+      config = Config.validate!([])
+      assert config[:browser_launch_opts] == []
+    end
+
+    test "is included in setup_all_keys" do
+      assert :browser_launch_opts in Config.setup_all_keys()
+    end
+  end
+end