Simulation and tests

Use the cheapest environment that can prove the behavior. Pure logic tests are fast, subsystem simulations exercise dynamics, and robot tests validate wiring and physics.

Testing layers

Do not skip directly to enabled hardware for logic that can be proven on a laptop.

Test pure decisions

@Test
void upperLimitBlocksPositiveVoltage() {
  Inputs inputs = new Inputs(1.2, 0.0, true, false, true);
  assertEquals(0.0, limits.apply(4.0, inputs), 1e-9);
  assertEquals(-4.0, limits.apply(-4.0, inputs), 1e-9);
}

Tests should describe behavior, not private implementation.

Fake IO

A fake adapter records outputs and supplies controlled inputs. It can verify sensor disconnection, limits, timeouts, and state transitions without vendor hardware.

final class FakeElevatorIO implements ElevatorIO {
  Inputs inputs = new Inputs(0, 0, 0, 0, true);
  double commandedVolts;

  public Inputs updateInputs() { return inputs; }
  public void setVoltage(double volts) { commandedVolts = volts; }
  public void stop() { commandedVolts = 0; }
}

Test time explicitly

Commands, debouncers, and timeouts depend on scheduler time. Use the framework’s test timing support or inject a clock. Avoid tests that sleep and hope enough time passed.

Hardware test record

Before enabling, state the expected motion, maximum output, stop condition, disable operator, and telemetry to watch. Afterward, record what happened—not only whether the test “worked.”