Class: Capybara::Lightpanda::Downloads

Inherits:
Object
  • Object
show all
Defined in:
lib/capybara/lightpanda/downloads.rb

Overview

File-download tracker built on Browser.setDownloadBehavior (upstream PR #2722, build >= 7545, guaranteed by MINIMUM_NIGHTLY_BUILD). When a navigation response carries Content-Disposition: attachment, Lightpanda streams the body to disk under downloadPath and — with eventsEnabled: true — emits Browser.downloadWillBegin / Browser.downloadProgress. We mirror those into a completed-files list + a blocking wait, the way ferrum's Downloads does.

IMPORTANT: the trigger is Content-Disposition: attachment, NOT MIME type. A text/csv (or any) response without that header is rendered as a normal navigation, not downloaded — which is why Capybara's MIME-triggered :download shared spec stays in capybara_skip.

Structure deliberately mirrors Network (same browser ref, same mutex + subscribe/unsubscribe lifecycle, same reset-after-disposeBrowserContext contract) so the two trackers behave identically under create_page/reset.

Constant Summary collapse

DOWNLOAD_BEGIN_GRACE =

How long #wait gives a download to BEGIN (the downloadWillBegin frame can arrive a beat after the click that triggers it, once the click's own wait_for_idle has already returned). Once a download has begun we wait the full timeout for it to finish.

1.0

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(browser) ⇒ Downloads

Returns a new instance of Downloads.



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# File 'lib/capybara/lightpanda/downloads.rb', line 32

def initialize(browser)
  @browser = browser
  @path = nil
  @enabled = false
  @mutex = Mutex.new
  @pending = {}  # guid => on-disk basename (from suggestedFilename)
  @files = []    # absolute paths of completed downloads, in order
  @started = 0   # monotonic count of downloads begun this session
  @will_handler = nil
  @progress_handler = nil
end

Instance Attribute Details

#browser ⇒ Object (readonly)

Returns the value of attribute browser.



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# File 'lib/capybara/lightpanda/downloads.rb', line 24

def browser
  @browser
end

#path ⇒ Object (readonly)

Returns the value of attribute path.



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# File 'lib/capybara/lightpanda/downloads.rb', line 24

def path
  @path
end

Instance Method Details

#clear ⇒ Object 



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# File 'lib/capybara/lightpanda/downloads.rb', line 108

def clear
  @mutex.synchronize do
    @files.clear
    @pending.clear
    @started = 0
  end
end

#enable(save_path) ⇒ Object

Opt into downloads, writing completed files under save_path. No-op when save_path is blank — downloads then stay at Lightpanda's deny default. Connection-scoped (browser.command) like Network.enable; Browser#create_page calls this after the context is loaded (the CDP method is a no-op without one). Subscribe BEFORE the wire toggle so no event can slip past, and roll the handlers back if the command fails.



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# File 'lib/capybara/lightpanda/downloads.rb', line 50

def enable(save_path)
  return if @enabled || save_path.to_s.empty?

  @path = File.expand_path(save_path.to_s)
  FileUtils.mkdir_p(@path)
  subscribe
  begin
    browser.command("Browser.setDownloadBehavior",
                    behavior: "allow", downloadPath: @path, eventsEnabled: true)
  rescue StandardError
    unsubscribe
    @path = nil
    raise
  end
  @enabled = true
end

#files ⇒ Object

Absolute paths of downloads completed this session (newest last).



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# File 'lib/capybara/lightpanda/downloads.rb', line 68

def files
  @mutex.synchronize { @files.dup }
end

#in_progress? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/capybara/lightpanda/downloads.rb', line 79

def in_progress?
  @mutex.synchronize { @pending.any? }
end

#reset ⇒ Object

Wipe local state after Target.disposeBrowserContext, which drops both the subscriptions and the per-connection download config — leaving



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# File 'lib/capybara/lightpanda/downloads.rb', line 119

def reset
  unsubscribe
  clear
  @enabled = false
  @path = nil
end

#started_count ⇒ Object

Monotonic count of downloads that have begun this session. Used by #wait to detect "a download started since I was called" even after the event queue has drained and @pending is empty again.



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# File 'lib/capybara/lightpanda/downloads.rb', line 75

def started_count
  @mutex.synchronize { @started }
end

#wait(timeout: 5) ⇒ Object

Block until in-flight downloads finish, then return the completed-file list. Non-raising, matching Network#wait_for_idle.

The triggering click returns (its wait_for_idle settles on the navigation's network response) slightly BEFORE the downloadWillBegin frame is processed, so a naive wait until !in_progress? would see an empty queue and return before the download even registered. Instead: give a download up to DOWNLOAD_BEGIN_GRACE to begin (tracked by the monotonic @started counter, immune to the queue already having drained), then wait up to timeout for every in-flight download to finish.



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# File 'lib/capybara/lightpanda/downloads.rb', line 93

def wait(timeout: 5)
  baseline = started_count
  clock = -> { ::Process.clock_gettime(::Process::CLOCK_MONOTONIC) }
  hard_deadline = clock.call + timeout
  begin_deadline = clock.call + [timeout, DOWNLOAD_BEGIN_GRACE].min

  loop do
    began = started_count > baseline
    done = (began ? !in_progress? : clock.call >= begin_deadline) || clock.call >= hard_deadline
    return files if done

    sleep 0.02
  end
end