Motion: add tests for the axis autoenable

Add Motion::Enabled() to get the current axis enablement status.

src/modules/motion.h

@@ -77,6 +77,9 @@ public:
     /// @returns true if the init was successful (TMC2130 responded ok)
     bool InitAxis(Axis axis);
 
+    /// Return the axis power status.
+    bool Enabled(Axis axis) const { return axisData[axis].enabled; }
+
     /// Set axis power status. One must manually ensure no moves are currently being
     /// performed by calling QueueEmpty().
     void SetEnabled(Axis axis, bool enabled);

tests/unit/modules/motion/test_motion.cpp

@@ -31,6 +31,24 @@ TEST_CASE("motion::basic", "[motion]") {
     REQUIRE(motion.Position(Idler) == 10);
 }
 
+TEST_CASE("motion::auto_axis_enable", "[motion]") {
+    // by default the axis should start disabled
+    REQUIRE(motion.Enabled(Pulley) == false);
+
+    // enable manually the axis
+    motion.SetEnabled(Pulley, true);
+    REQUIRE(motion.Enabled(Pulley) == true);
+
+    // now disable
+    motion.SetEnabled(Pulley, false);
+    REQUIRE(motion.Enabled(Pulley) == false);
+
+    // planning a move should enable the axis automatically
+    REQUIRE(motion.QueueEmpty());
+    motion.PlanMove<Pulley>(1.0_mm, 100.0_mm_s);
+    REQUIRE(motion.Enabled(Pulley) == true);
+}
+
 TEST_CASE("motion::unit", "[motion]") {
     // test AxisUnit conversion in the PlanMove and PlanMoveTo.
     REQUIRE(motion.QueueEmpty());