Replace usages of deprecated AssertLegacyTrait::assertHeader()

Adding the "Deprecated assertions" tag to add this into the kanban board https://contribkanban.com/board/Deprecatedassertions

+++ b/core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php
@@ -249,6 +249,19 @@ public function testAssertResponse() {
+  public function testAssertResponse() {

You tried to create a second method with the same name.

Looks good to me!

Title cleanup fail.

Perfect, thanks! All remaining references are either the method itself or its legacy tests:

[ibnsina:maintainer | Sun 16:38:46] $ grep -r "assertHeader(" * | grep -v "vendor"
core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php:   * Tests legacy assertHeader().
core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php:   * @expectedDeprecation AssertLegacyTrait::assertHeader() is deprecated in drupal:8.2.0 and is removed from drupal:10.0.0. Use $this->assertSession()->responseHeaderEquals() instead. See https://www.drupal.org/node/3129738
core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php:    $this->assertHeader('X-Drupal-Cache-Tags', 'http_response rendered');
core/tests/Drupal/FunctionalTests/AssertLegacyTrait.php:  protected function assertHeader($name, $value) {
core/tests/Drupal/FunctionalTests/AssertLegacyTrait.php:    @trigger_error('AssertLegacyTrait::assertHeader() is deprecated in drupal:8.2.0 and is removed from drupal:10.0.0. Use $this->assertSession()->responseHeaderEquals() instead. See https://www.drupal.org/node/3129738', E_USER_DEPRECATED);

PTBP for a backport that doesn't un-silence the deprecation. Thanks!

#6 ported to 8.8.x

@mondrake, Thanks for this information. I thought deprecation test handle similar to 9.x.

Removed deprecation test.

Adding patch for 8.9 and 9.0. Re-adding #16 just to combine all patch in single comment.

These look good. There is one other place the old method is used in D8:

core/modules/views_ui/src/Tests/UITestBase.php:      $this->assertHeader('Content-Type', 'application/json');

Should we fix that too?

Meanwhile I'll commit the 9.0.x patch but just waiting on a retest.

Forgot to add a note in the title.

Ah good call, thanks @mondrake. I did not actually expect them to still be around in 8.9! I guess it's because it was a base class and we didn't want to rm -rf those since they can be considered API.

Committed the backports to 9.0.x, 8.9.x, and 8.8.x. Thanks all!

#28 did not take for some reason.