Unit Testing¶

Sen comes with a dedicated TestKernel and TestComponent to ease the integration into unit testing frameworks (can be found here: libs/kernel/include/sen/kernel/test_kernel.h).

Some examples on the usage can be found directly in the unit tests Sen is using internally (see libs/kernel/test/unit/test_kernel/test_kernel_test.cpp).

HINT: This type of testing is only suitable for simple tests which don't involve multiple components with different execution rates or deferred methods.

The double tick¶

In case you want your code to react to property-changed callbacks you need to make sure to call kernel.tick() twice or directly add the tick count as parameter: kernel.tick(2).

To explain this, we need to take a look in the ways of working of Sen.

The changed properties, which will be retrieved within the next cycles drain phase ❷, are collected by Sen in the Commit phase ❶ of the current cycle.

When we push updates to the object within a unit-test, this happens in the time between the kernel steps ❸, i.e. the time the kernel waits for the next tick(). As the queue of changed properties is already created at this point of time, they require another tick() to be visible within the object getProperty().

Example¶

/// Example of a google test for checking the property-change callbacks via the test kernel.
TEST(TestKernel, AircraftObject)
{
  auto aircraft = std::make_shared<rpr::AircraftBase<>>(
    "entityName", ::rpr::EntityTypeStruct(), rpr::EntityIdentifierStruct {}, ::rpr::EntityTypeStruct());

  sen::kernel::TestComponent component;

  uint16_t lastValue = 0;

  component.onInit(
    [&](sen::kernel::InitApi&& api) -> sen::kernel::PassResult
    {
      const auto source = api.getSource("local.test");
      source->add(aircraft);

      aircraft
        ->onAcousticSignatureIndexChanged(
          {api.getWorkQueue(), [&]() { lastValue = aircraft->getAcousticSignatureIndex(); }})
        .keep();

      return sen::kernel::done();
    });

  component.onRun([&](auto& api) { return api.execLoop(std::chrono::seconds(1)); });

  sen::kernel::TestKernel kernel(&component);

  aircraft->setNextAcousticSignatureIndex(1);
  kernel.step(2);
  EXPECT_EQ(1, lastValue);

  aircraft->setNextAcousticSignatureIndex(2);
  kernel.step(2);
  EXPECT_EQ(2, lastValue);

  aircraft->setNextAcousticSignatureIndex(3);
  kernel.step(2);
  EXPECT_EQ(3, lastValue);
}