The documentation should be more explicit about PHPUnit requesting the webserver user to perform all functional tests

This is the same situation as with simpletest in Drupal 7. It isn't actually true that it must be the same user. A user in the same group as the web server user will do if file permissions are configured accordingly.

+++ b/core/tests/README.md
@@ -13,3 +13,17 @@
   ./vendor/bin/phpunit -c core --testsuite functional
   ./vendor/bin/phpunit -c core --testsuite functional-javascript
...
+sudo -u www-data ./vendor/bin/phpunit -c core --testsuite functional
+sudo -u www-data ./vendor/bin/phpunit -c core --testsuite functional-javascript

There should be an equal sign '=' between --testsuite and the argument.

+++ b/core/phpunit.xml.dist
@@ -6,8 +6,11 @@
+-->
+<!-- PHPUnit expects functional tests to be run with either a privileged user
+ or your Unix user. See core/tests/README.md for details.
 -->

I really like this! Of course we can improve this documentation a lot more, its a process, rather than a steady state, but this itself improves things. I have a bit of a feeling that the grammar is weird, but its really just a feeling.

Who's running tests? In the most of the cases the developer who also wrote that test. And writing a test always brings you to BrowserTestBase class. I would provide full instructions in the docblock of that class. BTW, it's the first time I notice that we have a core/tests/README.md file :)

Also I would add that printerClass attribute/value should go inside <phpunit ...> tag. I was confused initially by the phpunit.xml.dist documentation, it was not very clear where that should go.

Ok, then.

meh, don't do the "su www-data" dance if you are developing locally. Run Apache/Nginx under your own user account instead, as described in https://klau.si/dev

This is a really nice improvment and will help people. But...

+++ b/core/phpunit.xml.dist
@@ -1,19 +1,23 @@
+<!-- PHPUnit expects functional tests to be run with either a privileged user
+ or your Unix user. See core/tests/README.md and

+++ b/core/tests/README.md
@@ -10,6 +10,29 @@
+web server user. You can either configure Apache (or nginx) to run as your own
+Unix user or run tests as a privileged user instead.
...
+To develop locally, the recommended approach is to run tests as your own Unix
+user. To achieve that, configure `/etc/apache2/envvars` and change the default

I think saying "Unix user" is a bit weird. What is someone who uses OS X or windows to think?

Sorry for posting twice. The site was stuck and I pressed again the button.

1. +++ b/core/phpunit.xml.dist
   @@ -1,19 +1,23 @@
    <!-- TODO set checkForUnintentionallyCoveredCode="true" once https://www.drupal.org/node/2626832 is resolved. -->
   

   Why is this TODO staying here when you move the other... I think we should move this one too.

2. +++ b/core/tests/README.md
   @@ -10,6 +10,29 @@
   +  ./vendor/bin/phpunit -c core --testsuite=functional
   +  ./vendor/bin/phpunit -c core --testsuite=functional-javascript
   ...
   +sudo -u www-data ./vendor/bin/phpunit -c core --testsuite=functional
   +sudo -u www-data ./vendor/bin/phpunit -c core --testsuite=functional-javascript
   

   This is not right - at least according to the help when I do phpunit --help

   Test Selection Options:
   
     --filter <pattern>        Filter which tests to run.
     --testsuite <pattern>     Filter which testsuite to run.
   

Testing for me shows that #10 is not right.

2. I was also under the impression --filter
didn't need the equal sign but it works equally well so I don't have any strong opinion.

Well, let's go with what the official documentation says ...

+++ b/core/tests/README.md
@@ -13,3 +13,26 @@
+user. To achieve that, configure `/etc/apache2/envvars` and change the default
+Apache user to run as your system user. Example:

I'm running into this problem, and that file doesn't seem to exist on my Mac (v10.10)

On Mac the config should be under /etc/apache2/httpd.conf. I think it's probably better to document the location in the docs, instead of the patch - as I suspect it will differ from installation to installation.

To continue from the above comment, and more specifically, for mac I found installation under /etc/apache2/httpd.conf in this section:

<IfModule unixd_module>
#
# If you wish httpd to run as a different user or group, you must run
# httpd as root initially and it will switch.
#
# User/Group: The name (or #number) of the user/group to run httpd as.
# It is usually good practice to create a dedicated user and group for
# running httpd, as with most system services.
#
User _www
Group _www

</IfModule>

+++ b/core/tests/README.md
@@ -13,3 +13,29 @@
+To develop locally, the recommended approach is to run tests as your own system
+user. To achieve that, change the default Apache user to run as your system
+user. Typically, you'd need to modify `/etc/apache2/envvars` on Linux or

Mh, this approach is potentially less secure, as your database server then might be able to access any data of your user. We should at least have some sort of notion that this is less secure than the other option.

Thank you! Personally I think we can always iterate on here

+++ b/core/tests/README.md
@@ -13,3 +13,29 @@
+`/etc/apache2/envvars` on Linux or `/etc/apache2/httpd.conf` on the Mac.

the Mac => Mac

Also, maybe we can give a Mac example:

User <your-user>
Group <your-group>

Great, thanks. Seems ready.

This is helpful and a good start and I agree with @dawehner this can be iterated on further.

Committed and pushed cf37e90 to 8.3.x and c40dd5d to 8.2.x and dbcfdad to 8.1.x. Thanks!