Using Rules withing SimpleTest

I'm working on providing Rules support for the Relation module #1137552: Rules support. Most of the code is just providing entity metadata and thus letting entity api do most of the work with creating new entities. But setting the endpoints requires a bit of custom code, and because of that, I'd like to have to Relation specific tests for the Rules support.

However, whatever I do with a Rule within a test, I can't get it working.
This fairly simple code was as easy as I could make it:

$rule = rules_import('{ "rules_full_test_rule" : {
    "LABEL" : "Full test rule",
    "PLUGIN" : "reaction rule",
    "REQUIRES" : [ "rules" ],
    "ON" : [ "node_view" ],
    "DO" : [
      { "entity_create" : {
          "USING" : {
            "type" : "node",
            "param_type" : "page",
            "param_title" : "Node 1",
            "param_author" : [ "site:current-user" ]
          },
          "PROVIDE" : { "entity_created" : { "node_1" : "Node 1" } }
        }
      }
    ]
  }
}', $error);
if (!empty($error)) {
  $this->verbose('rules_import returned: ' . $error);
} 
else {
  $this->verbose('Rule imported succesfully');
}
$creation_rule->execute();

It fails with:
RulesException: Argument <em class="placeholder">node</em> is missing. in RulesPlugin->setUpState() (line 469 of /var/www/drupal-7.2/sites/all/modules/rules/includes/rules.core.inc).
It's probably something simple that I need to manually initialize or so in the test, but from looking at the tests that are in Rules itself, I can't figure out what I'm missing.