For BC purposes \Drupal\Tests\BrowserTestBase::drupalPostForm should return the HTML of the rendered page

So... something like this?

@Lendude this patch contains 'The HTML of the rendered page.' on the next line . is it correct ?

Combined patch from #2, #3, #8.

updating status.

+++ b/core/tests/Drupal/Tests/BrowserTestBase.php
@@ -920,6 +920,9 @@ protected function submitForm(array $edit, $submit, $form_html_id = NULL) {
+   *
+   * @return string
+   *   The HTML of the rendered page.

@@ -938,6 +941,8 @@ protected function drupalPostForm($path, $edit, $submit, array $options = []) {
+
+    return $this->getSession()->getPage()->getContent();
   }

Should we document here that the recommended way is to use $this->getSession()->getPage()->getContent() or actually the assertions we provide via the webAssert?

1. +++ b/core/tests/Drupal/Tests/BrowserTestBase.php
   @@ -938,6 +941,11 @@ protected function drupalPostForm($path, $edit, $submit, array $options = []) {
   +    // Returns response content for BC purposes. Feel free to use the webAssert
   +    // object for your assertions.
   

   What do you think about moving the hint to webAssert into the function documentation itself? This would help a bit in terms of discovery, as people will most likely read the function documentation instead of the actual code of the function.

2. +++ b/core/tests/Drupal/Tests/BrowserTestBase.php
   @@ -938,6 +941,11 @@ protected function drupalPostForm($path, $edit, $submit, array $options = []) {
   +    // @see \Drupal\simpletest\WebTestBase::drupalPostForm()
   

   This @see feels a little bit weird ... I would have probably skipped that :)

Thank you!

Are we going to want to deprecate the return for 9.0.x or just leave it like this?

Thanks all for the work on this!

I've added a draft CR, please review =) https://www.drupal.org/node/2907815

Thank you @Manuel Garcia to create the change record. I fixed a tiny bit of it, but it looks good for me.

Yes return deprecation is hard.

Committed/pushed to 8.5.x and cherry-picked to 8.4.x. Thanks!

publish the change record