devbrowser

devbrowser

A lightweight Go library for launching and controlling web browsers programmatically, designed for automation and development tools.

Usage

The main entry point is the New function, which creates a new browser controller:

import "github.com/tinywasm/devbrowser"

type myServerConfig struct{}
func (myServerConfig) GetServerPort() string { return "8080" }

type myUI struct{}
func (myUI) ReturnFocus() {}

func main() {
	exitChan := make(chan bool)
	browser := devbrowser.New(myServerConfig{}, myUI{}, exitChan)
	err := browser.OpenBrowser()
	if err != nil {
		// handle error
	}
	// ... use browser ...
	browser.CloseBrowser()
}

Public API

• New(sc serverConfig, ui userInterface, exitChan chan bool) *DevBrowser: Create a new DevBrowser instance.

• (*DevBrowser) OpenBrowser() error: Launch a new browser window.

• (*DevBrowser) CloseBrowser() error: Close the browser and clean up resources.

• (*DevBrowser) Reload() error: Reload the current page in the browser.

• (*DevBrowser) RestartBrowser() error: Restart the browser (close and reopen).

• (*DevBrowser) BrowserStartUrlChanged(fieldName, oldValue, newValue string) error: Handle changes to the start URL and restart the browser if open.

• (*DevBrowser) BrowserPositionAndSizeChanged(fieldName, oldValue, newValue string) error: Change the browser window's position and size, and restart the browser.

• (*DevBrowser) Name() string and (*DevBrowser) Label() string: For UI integration, returns the component name and label.

• (*DevBrowser) Execute(progress func(msgs ...any)): For UI integration, toggles browser open/close and reports progress.

• (*DevBrowser) SetHeadless(headless bool): Configure whether the browser runs in headless mode (without a visible UI).

  • Signature: func (b *DevBrowser) SetHeadless(headless bool)
  • Default: false (shows the browser window). This is convenient for local development and debugging.
  • Tests: the test helper DefaultTestBrowser() configures the returned DevBrowser with headless = true so unit tests run without requiring a graphical display.
  • Notes: Call this before OpenBrowser() (or before the browser context is created) to ensure the headless flag is applied when launching Chrome/Chromium.
  • Example:

db := devbrowser.New(myServerConfig{}, myUI{}, exitChan)
// run with no UI (useful in CI/tests)
db.SetHeadless(true)
err := db.OpenBrowser()
if err != nil {
		// handle error
}

• (*DevBrowser) GetConsoleLogs() ([]string, error): Capture console messages from the loaded page.
  • Signature: func (b *DevBrowser) GetConsoleLogs() ([]string, error)
  • Behavior: injects a small script into the page that maintains window.__consoleLogs and returns its contents as a slice of strings. Captures console.log, console.error, console.warn, and console.info messages.
  • Requirements: the browser context must be initialized (OpenBrowser() called and context created). Returns an error if the context is not ready or the evaluation fails.
  • Example:

logs, err := db.GetConsoleLogs()
if err != nil {
		// handle error
}
for _, l := range logs {
		fmt.Println(l)
}

• (*DevBrowser) ClearConsoleLogs() error: Clear the in-page captured console log buffer.
  • Signature: func (b *DevBrowser) ClearConsoleLogs() error
  • Behavior: executes a small script that resets window.__consoleLogs = [] if present.
  • Requirements: the browser context must be initialized. Returns an error if the evaluation fails.
  • Example:

err := db.ClearConsoleLogs()
if err != nil {
		// handle error
}