Patching composer.json shows we need to add module dependencies

To verify this, here is a patch which alters composer.json but only changes the text and does nothing else.

In the console output https://dispatcher.drupalci.org/job/drupal8_contrib_patches/33118/console we get:

Adding testing (require-dev) dependencies.
Adding require-dev
sudo -u www-data /usr/local/bin/composer  require --no-interaction 'drupal/devel_generate:*' 'drupal/rules:*' --prefer-stable --no-progress --no-suggest --working-dir /var/www/html
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 4 installs, 0 updates, 0 removals
  - Installing drupal/devel (1.2.0): Loading from cache
  - Installing drupal/typed_data (1.0.0-alpha1): Downloading (100%)
  - Installing drupal/rules (3.0.0-alpha4): Downloading (100%)

Then after the patch has been applied we get (with ... for omitted lines) :

----------------   Starting update_dependencies   ----------------
...
composer.json changed by patch: recalculating depenendices
...
Removing dev dependencies: sudo -u www-data /usr/local/bin/composer remove drupal/devel_generate --no-interaction --working-dir /var/www/html
...
Removing dev dependencies: sudo -u www-data /usr/local/bin/composer remove drupal/rules --no-interaction --working-dir /var/www/html
...
Removing project: sudo -u www-data /usr/local/bin/composer remove drupal/scheduler --no-interaction --working-dir /var/www/html

Then the Scheduler module is re-added, but with no dependencies

  - Installing drupal/scheduler (dev-ancillary-branch): Mirroring from /var/lib/drupalci/workdir/scheduler

So the question is: Do we have to repeat the dependency and test-dependency information in both .info.yml and composer.json? Or should the DrupalCI procedure have re-added the dependencies using what is specified in .info.yml?

Patch to add drupal/devel as a test dependency in composer.json. The rules dependencies have not been changed, so rules tests will still fail.

That's good the devel module is re-added:

Adding testing (require-dev) dependencies.
Composer Command: sudo -u www-data /usr/local/bin/composer require 'drupal/devel:>=1.0' --prefer-stable --no-progress --no-suggest --working-dir /var/www/html
Updating dependencies (including require-dev)
  - Installing drupal/devel (1.2.0): Loading from cache

and SchedulerDevelGenerateTest now passes.

This patch adds new composer.json to the scheduler_rules_integration sub-module. Not sure it this is the correct way to go, as adding 'rules' into the require-dev list in the main composer.json would probably fix the problem. However, having a separate composer.json for the sub-module feels the right thing to do. Lots of guessing here, so this probably won't pass first time.

Maybe it should be "drupal/rules" not "rules/rules" as per .info.yml

Thanks for the patch. Yes the tests do pass with your patch, but I knew that was going to happen if you add the test dependency to the main composer,json file. The critical thing, however, is that we already have the rules test dependency defined, in the sub-module /scheduler_rules_integration/scheduler_rules_integration.info.yml file. It is only required as a test dependency for that sub-module, so should not be in the main project scheduler.info.yml file or composer.json file. Otherwise you cannot test Scheduler locally if you dont have rules, or rules is not working (there is no full release yet). That is why we split out the rules integration code into a sub-module which can be enabled and/or tested separately.

I have an idea that the tests in #10 failed because there is not currently any /scheduler_rules_integration/composer.json file so the patch to this file did not trigger a re-evaluation of the dependencies in the patched file.

Thanks for the hint about using 4 spaces.

Now that the file /scheduler_rules_integration/composer.json exists we can test the dependencies properly.

Try again now that the committed composer.json syntax is correct.

Now adding require-dev to the rules file

OK, so it looks like idebr was right, and this is also confirmed by #2692407-34: Test_dependencies are downloaded before applying patches, rather than after.

When require-dev drupal/rules is added to the main composer.json I can still run local PHPunit non-rules tests if the Rules module is not available. This is good because it does not hinder non-rules development, which is what I was concerned about.

This patch does not add rules:rules to the test dependencies in .info.yml file.

I must get a json syntax checker!

OK, that works. Now to see if changing "drupal/devel" to "drupal/devel_generate" works, as this is what we have in .info.yml

Having committed the minimum require-dev to the main module composer.json and minimum require to the sub-module, it will be useful to see if this is sufficient to re-load the dependencies after a dummy patch to the main composer.json. I expect it will not, and this test will fail, but useful to know for certain.

So the sub-modules actual dependencies are removed and not re-added, if the main module's composer.json is patched.

As we do not want to add require-dev drupal/rules to the main module's composer file I think we may have to leave it here, and just accept that patches to the main module composer.json will cause the sub-module tests to fail. But that does seem very limiting.

Here's the patch. Added the equivalent test dependency to .info.yml to keep them in sync.

Fixed. Thanks @idebr for your help.