Fix examples and start testing them (#609)

* Fix examples

* Added test for examples

* Fix example testing code

* Sweep example fix

* Reformat examples

* Test examples from the docs too

* Add docutils to the test requirements

* Example test fix on win+cleanup

* Use union

examples/Ex009_Polylines.py

@@ -6,6 +6,7 @@ import cadquery as cq
 
 # Define the points that the polyline will be drawn to/thru
 pts = [
+    (0, H / 2.0),
     (W / 2.0, H / 2.0),
     (W / 2.0, (H / 2.0 - t)),
     (t / 2.0, (H / 2.0 - t)),
@@ -30,7 +31,7 @@ pts = [
 # 3.  Only half of the I-beam profile has been drawn so far. That half is
 #     mirrored around the Y-axis to create the complete I-beam profile.
 # 4.  The I-beam profile is extruded to the final length of the beam.
-result = cq.Workplane("front").moveTo(0, H / 2.0).polyline(pts).mirrorY().extrude(L)
+result = cq.Workplane("front").polyline(pts).mirrorY().extrude(L)
 
 # Displays the result of this script
 show_object(result)

examples/Ex010_Defining_an_Edge_with_a_Spline.py

@@ -18,7 +18,7 @@ sPnts = [
 
 # 2.  Generate our plate with the spline feature and make sure it is a
 #     closed entity
-r = s.lineTo(3.0, 0).lineTo(3.0, 1.0).spline(sPnts).close()
+r = s.lineTo(3.0, 0).lineTo(3.0, 1.0).spline(sPnts, includeCurrent=True).close()
 
 # 3.  Extrude to turn the wire into a plate
 result = r.extrude(0.5)

examples/Ex013_Locating_a_Workplane_on_a_Vertex.py

@@ -11,7 +11,7 @@ result = cq.Workplane("front").box(3, 2, 0.5)
 # 3a. The top-most Z face is selected using the >Z selector.
 # 3b. The lower-left vertex of the faces is selected with the <XY selector.
 # 3c. A new workplane is created on the vertex to build future geometry on.
-result = result.faces(">Z").vertices("<XY").workplane()
+result = result.faces(">Z").vertices("<XY").workplane(centerOption="CenterOfMass")
 
 # 4.  A circle is drawn with the selected vertex as its center.
 # 4a. The circle is cut down through the box to cut the corner out.

examples/Ex023_Sweep.py

@@ -17,7 +17,7 @@ frenetShell = cq.Workplane("XY").circle(1.0).sweep(path, makeSolid=True, isFrene
 defaultRect = cq.Workplane("XY").rect(1.0, 1.0).sweep(path)
 
 # Switch to a polyline path, but have it use the same points as the spline
-path = cq.Workplane("XZ").polyline(pts)
+path = cq.Workplane("XZ").polyline(pts, includeCurrent=True)
 
 # Using a polyline path leads to the resulting solid having segments rather than a single swept outer face
 plineSweep = cq.Workplane("XY").circle(1.0).sweep(path)
@@ -32,5 +32,5 @@ arcSweep = cq.Workplane("XY").circle(0.5).sweep(path)
 show_object(defaultSweep)
 show_object(frenetShell.translate((5, 0, 0)))
 show_object(defaultRect.translate((10, 0, 0)))
-show_object(plineSweep.translate((15, 0, 0)))
+show_object(plineSweep)
 show_object(arcSweep.translate((20, 0, 0)))

examples/Ex024_Sweep_With_Multiple_Sections.py

@@ -70,11 +70,11 @@ arcSweep = (
     .workplane(offset=-5)
     .moveTo(0, 4)
     .circle(1.5)
-    .workplane(offset=5)
+    .workplane(offset=5, centerOption="CenterOfMass")
     .circle(1.5)
     .moveTo(0, -8)
     .circle(1.0)
-    .workplane(offset=-5)
+    .workplane(offset=-5, centerOption="CenterOfMass")
     .circle(1.0)
     .sweep(path, multisection=True)
 )