DEV: add validation for aerodynamic surfaces in rocket plots

Author: Gui-FernandesBR

rocketpy/plots/rocket_plots.py

@@ -212,6 +212,9 @@ def draw(self, vis_args=None, plane="xz", *, filename=None):
             eps, jpg, jpeg, pdf, pgf, png, ps, raw, rgba, svg, svgz, tif, tiff
             and webp (these are the formats supported by matplotlib).
         """
+
+        self.__validate_aerodynamic_surfaces()
+
         if vis_args is None:
             vis_args = {
                 "background": "#EEEEEE",
@@ -248,6 +251,12 @@ def draw(self, vis_args=None, plane="xz", *, filename=None):
         plt.tight_layout()
         show_or_save_plot(filename)
 
+    def __validate_aerodynamic_surfaces(self):
+        if not self.rocket.aerodynamic_surfaces:
+            raise ValueError(
+                "The rocket must have at least one aerodynamic surface to be drawn."
+            )
+
     def _draw_aerodynamic_surfaces(self, ax, vis_args, plane):
         """Draws the aerodynamic surfaces and saves the position of the points
         of interest for the tubes."""
@@ -399,6 +408,8 @@ def _draw_generic_surface(
 
     def _draw_tubes(self, ax, drawn_surfaces, vis_args):
         """Draws the tubes between the aerodynamic surfaces."""
+        radius = 0
+        last_x = 0
         for i, d_surface in enumerate(drawn_surfaces):
             # Draw the tubes, from the end of the first surface to the beginning
             # of the next surface, with the radius of the rocket at that point