all pending manual tests done!

Also ensure we autosave.

Manual_tests.md

@@ -0,0 +1,18 @@
+I care a lot about being able to automatically check _any_ property about my
+program before it ever runs. However, some things don't have tests yet, either
+because I don't know how to test them or because I've been lazy. I'll at least
+record those here.
+
+### Compromises
+
+Lua is dynamically typed. Tests can't patch over lack of type-checking.
+
+* All strings are UTF-8. Bytes within them are not characters. I try to label
+  byte offsets as _offset, and character positions as _pos. For example,
+  string.sub should never use a _pos to substring, only an _offset.
+
+### Todo list
+
+resize:
+  create a file containing a long line of characters without spaces. try
+  resizing the window vertically and horizontally, as far as possible.

app.lua

@@ -276,8 +276,21 @@ end
 function App.open_for_writing(filename)
   App.filesystem[filename] = ''
   return {
-    write = function(self, s)
-              App.filesystem[filename] = App.filesystem[filename]..s
+    write = function(self, ...)
+              local args = {...}
+              for i,s in ipairs(args) do
+                App.filesystem[filename] = App.filesystem[filename]..s
+              end
+            end,
+    close = function(self)
+            end
+  }
+end
+
+function App.open_for_reading(filename)
+  return {
+    lines = function(self)
+              return App.filesystem[filename]:gmatch('[^\n]+')
             end,
     close = function(self)
             end
@@ -331,6 +344,7 @@ function App.disable_tests()
   App.newText = love.graphics.newText
   App.screen.draw = love.graphics.draw
   App.width = function(text) return text:getWidth() end
+  App.open_for_reading = function(filename) return io.open(filename, 'r') end
   App.open_for_writing = function(filename) return io.open(filename, 'w') end
   App.getClipboardText = love.system.getClipboardText
   App.setClipboardText = love.system.setClipboardText

drawing.lua

@@ -2,6 +2,8 @@
 Drawing = {}
 geom = require 'geom'
 
+require 'drawing_tests'
+
 -- All drawings span 100% of some conceptual 'page width' and divide it up
 -- into 256 parts.
 function Drawing.draw(line)
@@ -202,7 +204,7 @@ end
 
 function Drawing.in_drawing(drawing, x,y)
   if drawing.y == nil then return false end  -- outside current page
-  return y >= drawing.y and y < drawing.y + Drawing.pixels(drawing.h) and x >= 16 and x < 16+Line_width
+  return y >= drawing.y and y < drawing.y + Drawing.pixels(drawing.h) and x >= Margin_left and x < Margin_left+Line_width
 end
 
 function Drawing.mouse_pressed(drawing, x,y, button)
@@ -258,6 +260,10 @@ function Drawing.mouse_released(x,y, button)
   if Current_drawing_mode == 'move' then
     Current_drawing_mode = Previous_drawing_mode
     Previous_drawing_mode = nil
+    if Lines.current_drawing then
+      Lines.current_drawing.pending = {}
+      Lines.current_drawing = nil
+    end
   elseif Lines.current_drawing then
     local drawing = Lines.current_drawing
     if drawing.pending then
@@ -334,8 +340,6 @@ function Drawing.mouse_released(x,y, button)
           drawing.pending.end_angle = geom.angle_with_hint(center.x,center.y, mx,my, drawing.pending.end_angle)
           table.insert(drawing.shapes, drawing.pending)
         end
-      elseif drawing.pending.mode == 'move' then
-        -- drop it
       elseif drawing.pending.mode == 'name' then
         -- drop it
       else
@@ -406,11 +410,19 @@ function Drawing.keychord_pressed(chord)
       end
     end
     drawing.pending.mode = 'square'
-  elseif App.mouse_down(1) and chord == 'p' and (Current_drawing_mode == 'polygon' or Current_drawing_mode == 'rectangle' or Current_drawing_mode == 'square') then
+  elseif App.mouse_down(1) and chord == 'p' and Current_drawing_mode == 'polygon' then
     local _,drawing = Drawing.current_drawing()
     local mx,my = Drawing.coord(App.mouse_x()-Margin_left), Drawing.coord(App.mouse_y()-drawing.y)
     local j = Drawing.insert_point(drawing.points, mx,my)
     table.insert(drawing.pending.vertices, j)
+  elseif App.mouse_down(1) and chord == 'p' and (Current_drawing_mode == 'rectangle' or Current_drawing_mode == 'square') then
+    local _,drawing = Drawing.current_drawing()
+    local mx,my = Drawing.coord(App.mouse_x()-Margin_left), Drawing.coord(App.mouse_y()-drawing.y)
+    local j = Drawing.insert_point(drawing.points, mx,my)
+    while #drawing.pending.vertices >= 2 do
+      table.remove(drawing.pending.vertices)
+    end
+    table.insert(drawing.pending.vertices, j)
   elseif chord == 'C-o' and not App.mouse_down(1) then
     Current_drawing_mode = 'circle'
   elseif App.mouse_down(1) and chord == 'a' and Current_drawing_mode == 'circle' then
@@ -476,17 +488,6 @@ function Drawing.keychord_pressed(chord)
       Lines.current_drawing_index = drawing_index
       Lines.current_drawing = drawing
     end
-  elseif App.mouse_down(1) and chord == 'v' then
-    local drawing_index,drawing,_,p = Drawing.select_point_at_mouse()
-    if drawing then
-      if Previous_drawing_mode == nil then
-        Previous_drawing_mode = Current_drawing_mode
-      end
-      Current_drawing_mode = 'move'
-      drawing.pending = {mode=Current_drawing_mode, target_point=p}
-      Lines.current_drawing_index = drawing_index
-      Lines.current_drawing = drawing
-    end
   elseif chord == 'C-n' and not App.mouse_down(1) then
     local drawing_index,drawing,point_index,p = Drawing.select_point_at_mouse()
     if drawing then

drawing_tests.lua

@@ -0,0 +1,674 @@
+-- major tests for drawings
+-- We minimize assumptions about specific pixels, and try to test at the level
+-- of specific shapes. In particular, no tests of freehand drawings.
+
+function test_creating_drawing_saves()
+  io.write('\ntest_creating_drawing_saves')
+  App.screen.init{width=120, height=60}
+  Filename = 'foo'
+  Lines = load_array{}
+  App.draw()
+  -- click on button to create drawing
+  App.run_after_mouse_click(8,Margin_top+8, 1)
+  -- filesystem contains drawing and an empty line of text
+  check_eq(App.filesystem['foo'], '```lines\n```\n\n', 'F - test_creating_drawing_saves')
+end
+
+function test_draw_line()
+  io.write('\ntest_draw_line')
+  -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
+  Filename = 'foo'
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  Current_drawing_mode = 'line'
+  App.draw()
+  check_eq(#Lines, 2, 'F - test_draw_line/baseline/#lines')
+  check_eq(Lines[1].mode, 'drawing', 'F - test_draw_line/baseline/mode')
+  check_eq(Lines[1].y, Margin_top+Drawing_padding_top, 'F - test_draw_line/baseline/y')
+  check_eq(Lines[1].h, 128, 'F - test_draw_line/baseline/y')
+  check_eq(#Lines[1].shapes, 0, 'F - test_draw_line/baseline/#shapes')
+  -- draw a line
+  App.run_after_mouse_press(Margin_left+5, Margin_top+Drawing_padding_top+6, 1)
+  App.run_after_mouse_release(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 1, 'F - test_draw_line/#shapes')
+  check_eq(#drawing.points, 2, 'F - test_draw_line/#points')
+  check_eq(drawing.shapes[1].mode, 'line', 'F - test_draw_line/shape:1')
+  local p1 = drawing.points[drawing.shapes[1].p1]
+  local p2 = drawing.points[drawing.shapes[1].p2]
+  check_eq(p1.x, 5, 'F - test_draw_line/p1:x')
+  check_eq(p1.y, 6, 'F - test_draw_line/p1:y')
+  check_eq(p2.x, 35, 'F - test_draw_line/p2:x')
+  check_eq(p2.y, 36, 'F - test_draw_line/p2:y')
+  -- The format on disk isn't perfectly stable. Table fields can be reordered.
+  -- So just reload from disk to verify.
+  Lines = load_from_disk(Filename)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 1, 'F - test_draw_line/save/#shapes')
+  check_eq(#drawing.points, 2, 'F - test_draw_line/save/#points')
+  check_eq(drawing.shapes[1].mode, 'line', 'F - test_draw_line/save/shape:1')
+  local p1 = drawing.points[drawing.shapes[1].p1]
+  local p2 = drawing.points[drawing.shapes[1].p2]
+  check_eq(p1.x, 5, 'F - test_draw_line/save/p1:x')
+  check_eq(p1.y, 6, 'F - test_draw_line/save/p1:y')
+  check_eq(p2.x, 35, 'F - test_draw_line/save/p2:x')
+  check_eq(p2.y, 36, 'F - test_draw_line/save/p2:y')
+end
+
+function test_draw_horizontal_line()
+  io.write('\ntest_draw_horizontal_line')
+  -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  Current_drawing_mode = 'manhattan'
+  App.draw()
+  check_eq(#Lines, 2, 'F - test_draw_horizontal_line/baseline/#lines')
+  check_eq(Lines[1].mode, 'drawing', 'F - test_draw_horizontal_line/baseline/mode')
+  check_eq(Lines[1].y, Margin_top+Drawing_padding_top, 'F - test_draw_horizontal_line/baseline/y')
+  check_eq(Lines[1].h, 128, 'F - test_draw_horizontal_line/baseline/y')
+  check_eq(#Lines[1].shapes, 0, 'F - test_draw_horizontal_line/baseline/#shapes')
+  -- draw a line that is more horizontal than vertical
+  App.run_after_mouse_press(Margin_left+5, Margin_top+Drawing_padding_top+6, 1)
+  App.run_after_mouse_release(Margin_left+35, Margin_top+Drawing_padding_top+26, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 1, 'F - test_draw_horizontal_line/#shapes')
+  check_eq(#drawing.points, 2, 'F - test_draw_horizontal_line/#points')
+  check_eq(drawing.shapes[1].mode, 'manhattan', 'F - test_draw_horizontal_line/shape_mode')
+  local p1 = drawing.points[drawing.shapes[1].p1]
+  local p2 = drawing.points[drawing.shapes[1].p2]
+  check_eq(p1.x, 5, 'F - test_draw_horizontal_line/p1:x')
+  check_eq(p1.y, 6, 'F - test_draw_horizontal_line/p1:y')
+  check_eq(p2.x, 35, 'F - test_draw_horizontal_line/p2:x')
+  check_eq(p2.y, p1.y, 'F - test_draw_horizontal_line/p2:y')
+end
+
+function test_draw_circle()
+  io.write('\ntest_draw_circle')
+  -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  Current_drawing_mode = 'line'
+  App.draw()
+  check_eq(#Lines, 2, 'F - test_draw_circle/baseline/#lines')
+  check_eq(Lines[1].mode, 'drawing', 'F - test_draw_circle/baseline/mode')
+  check_eq(Lines[1].y, Margin_top+Drawing_padding_top, 'F - test_draw_circle/baseline/y')
+  check_eq(Lines[1].h, 128, 'F - test_draw_circle/baseline/y')
+  check_eq(#Lines[1].shapes, 0, 'F - test_draw_circle/baseline/#shapes')
+  -- draw a circle
+  App.mouse_move(Margin_left+4, Margin_top+Drawing_padding_top+4)  -- hover on drawing
+  App.run_after_keychord('C-o')
+  App.run_after_mouse_press(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  App.run_after_mouse_release(Margin_left+35+30, Margin_top+Drawing_padding_top+36, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 1, 'F - test_draw_circle/#shapes')
+  check_eq(#drawing.points, 1, 'F - test_draw_circle/#points')
+  check_eq(drawing.shapes[1].mode, 'circle', 'F - test_draw_horizontal_line/shape_mode')
+  check_eq(drawing.shapes[1].radius, 30, 'F - test_draw_circle/radius')
+  local center = drawing.points[drawing.shapes[1].center]
+  check_eq(center.x, 35, 'F - test_draw_circle/center:x')
+  check_eq(center.y, 36, 'F - test_draw_circle/center:y')
+end
+
+function test_keys_do_not_affect_shape_when_mouse_up()
+  io.write('\ntest_keys_do_not_affect_shape_when_mouse_up')
+  -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  Current_drawing_mode = 'line'
+  App.draw()
+  -- hover over drawing and press 'o' without holding mouse
+  App.mouse_move(Margin_left+4, Margin_top+Drawing_padding_top+4)  -- hover on drawing
+  App.run_after_keychord('o')
+  -- no change to drawing mode
+  check_eq(Current_drawing_mode, 'line', 'F - test_keys_do_not_affect_shape_when_mouse_up/drawing_mode')
+  -- no change to text either because we didn't run the textinput event
+end
+
+function test_draw_circle_mid_stroke()
+  io.write('\ntest_draw_circle_mid_stroke')
+  -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  Current_drawing_mode = 'line'
+  App.draw()
+  check_eq(#Lines, 2, 'F - test_draw_circle_mid_stroke/baseline/#lines')
+  check_eq(Lines[1].mode, 'drawing', 'F - test_draw_circle_mid_stroke/baseline/mode')
+  check_eq(Lines[1].y, Margin_top+Drawing_padding_top, 'F - test_draw_circle_mid_stroke/baseline/y')
+  check_eq(Lines[1].h, 128, 'F - test_draw_circle_mid_stroke/baseline/y')
+  check_eq(#Lines[1].shapes, 0, 'F - test_draw_circle_mid_stroke/baseline/#shapes')
+  -- draw a circle
+  App.mouse_move(Margin_left+4, Margin_top+Drawing_padding_top+4)  -- hover on drawing
+  App.run_after_mouse_press(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  App.run_after_keychord('o')
+  App.run_after_mouse_release(Margin_left+35+30, Margin_top+Drawing_padding_top+36, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 1, 'F - test_draw_circle_mid_stroke/#shapes')
+  check_eq(#drawing.points, 1, 'F - test_draw_circle_mid_stroke/#points')
+  check_eq(drawing.shapes[1].mode, 'circle', 'F - test_draw_horizontal_line/shape_mode')
+  check_eq(drawing.shapes[1].radius, 30, 'F - test_draw_circle_mid_stroke/radius')
+  local center = drawing.points[drawing.shapes[1].center]
+  check_eq(center.x, 35, 'F - test_draw_circle_mid_stroke/center:x')
+  check_eq(center.y, 36, 'F - test_draw_circle_mid_stroke/center:y')
+end
+
+function test_draw_arc()
+  io.write('\ntest_draw_arc')
+  -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  Current_drawing_mode = 'circle'
+  App.draw()
+  check_eq(#Lines, 2, 'F - test_draw_arc/baseline/#lines')
+  check_eq(Lines[1].mode, 'drawing', 'F - test_draw_arc/baseline/mode')
+  check_eq(Lines[1].y, Margin_top+Drawing_padding_top, 'F - test_draw_arc/baseline/y')
+  check_eq(Lines[1].h, 128, 'F - test_draw_arc/baseline/y')
+  check_eq(#Lines[1].shapes, 0, 'F - test_draw_arc/baseline/#shapes')
+  -- draw an arc
+  App.run_after_mouse_press(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  App.mouse_move(Margin_left+35+30, Margin_top+Drawing_padding_top+36)
+  App.run_after_keychord('a')  -- arc mode
+  App.run_after_mouse_release(Margin_left+35+50, Margin_top+Drawing_padding_top+36+50, 1)  -- 45°
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 1, 'F - test_draw_arc/#shapes')
+  check_eq(#drawing.points, 2, 'F - test_draw_arc/#points')
+  check_eq(drawing.shapes[1].mode, 'arc', 'F - test_draw_horizontal_line/shape_mode')
+  local arc = drawing.shapes[1]
+  check_eq(arc.radius, 30, 'F - test_draw_arc/radius')
+  local center = drawing.points[arc.center]
+  check_eq(center.x, 35, 'F - test_draw_arc/center:x')
+  check_eq(center.y, 36, 'F - test_draw_arc/center:y')
+  check_eq(arc.start_angle, 0, 'F - test_draw_arc/start:angle')
+  check_eq(arc.end_angle, math.pi/4, 'F - test_draw_arc/end:angle')
+end
+
+function test_draw_polygon()
+  io.write('\ntest_draw_polygon')
+  -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  App.draw()
+  check_eq(Current_drawing_mode, 'line', 'F - test_draw_polygon/baseline/drawing_mode')
+  check_eq(#Lines, 2, 'F - test_draw_polygon/baseline/#lines')
+  check_eq(Lines[1].mode, 'drawing', 'F - test_draw_polygon/baseline/mode')
+  check_eq(Lines[1].y, Margin_top+Drawing_padding_top, 'F - test_draw_polygon/baseline/y')
+  check_eq(Lines[1].h, 128, 'F - test_draw_polygon/baseline/y')
+  check_eq(#Lines[1].shapes, 0, 'F - test_draw_polygon/baseline/#shapes')
+  -- first point
+  App.run_after_mouse_press(Margin_left+5, Margin_top+Drawing_padding_top+6, 1)
+  App.run_after_keychord('g')  -- polygon mode
+  -- second point
+  App.mouse_move(Margin_left+65, Margin_top+Drawing_padding_top+36)
+  App.run_after_keychord('p')  -- add point
+  -- final point
+  App.run_after_mouse_release(Margin_left+35, Margin_top+Drawing_padding_top+26, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 1, 'F - test_draw_polygon/#shapes')
+  check_eq(#drawing.points, 3, 'F - test_draw_polygon/vertices')
+  local shape = drawing.shapes[1]
+  check_eq(shape.mode, 'polygon', 'F - test_draw_polygon/shape_mode')
+  check_eq(#shape.vertices, 3, 'F - test_draw_polygon/vertices')
+  local p = drawing.points[shape.vertices[1]]
+  check_eq(p.x, 5, 'F - test_draw_polygon/p1:x')
+  check_eq(p.y, 6, 'F - test_draw_polygon/p1:y')
+  local p = drawing.points[shape.vertices[2]]
+  check_eq(p.x, 65, 'F - test_draw_polygon/p2:x')
+  check_eq(p.y, 36, 'F - test_draw_polygon/p2:y')
+  local p = drawing.points[shape.vertices[3]]
+  check_eq(p.x, 35, 'F - test_draw_polygon/p3:x')
+  check_eq(p.y, 26, 'F - test_draw_polygon/p3:y')
+end
+
+function test_draw_rectangle()
+  io.write('\ntest_draw_rectangle')
+  -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  App.draw()
+  check_eq(Current_drawing_mode, 'line', 'F - test_draw_rectangle/baseline/drawing_mode')
+  check_eq(#Lines, 2, 'F - test_draw_rectangle/baseline/#lines')
+  check_eq(Lines[1].mode, 'drawing', 'F - test_draw_rectangle/baseline/mode')
+  check_eq(Lines[1].y, Margin_top+Drawing_padding_top, 'F - test_draw_rectangle/baseline/y')
+  check_eq(Lines[1].h, 128, 'F - test_draw_rectangle/baseline/y')
+  check_eq(#Lines[1].shapes, 0, 'F - test_draw_rectangle/baseline/#shapes')
+  -- first point
+  App.run_after_mouse_press(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  App.run_after_keychord('r')  -- rectangle mode
+  -- second point/first edge
+  App.mouse_move(Margin_left+42, Margin_top+Drawing_padding_top+45)
+  App.run_after_keychord('p')
+  -- override second point/first edge
+  App.mouse_move(Margin_left+75, Margin_top+Drawing_padding_top+76)
+  App.run_after_keychord('p')
+  -- release (decides 'thickness' of rectangle perpendicular to first edge)
+  App.run_after_mouse_release(Margin_left+15, Margin_top+Drawing_padding_top+26, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 1, 'F - test_draw_rectangle/#shapes')
+  check_eq(#drawing.points, 5, 'F - test_draw_rectangle/#points')  -- currently includes every point added
+  local shape = drawing.shapes[1]
+  check_eq(shape.mode, 'rectangle', 'F - test_draw_rectangle/shape_mode')
+  check_eq(#shape.vertices, 4, 'F - test_draw_rectangle/vertices')
+  local p = drawing.points[shape.vertices[1]]
+  check_eq(p.x, 35, 'F - test_draw_rectangle/p1:x')
+  check_eq(p.y, 36, 'F - test_draw_rectangle/p1:y')
+  local p = drawing.points[shape.vertices[2]]
+  check_eq(p.x, 75, 'F - test_draw_rectangle/p2:x')
+  check_eq(p.y, 76, 'F - test_draw_rectangle/p2:y')
+  local p = drawing.points[shape.vertices[3]]
+  check_eq(p.x, 70, 'F - test_draw_rectangle/p3:x')
+  check_eq(p.y, 81, 'F - test_draw_rectangle/p3:y')
+  local p = drawing.points[shape.vertices[4]]
+  check_eq(p.x, 30, 'F - test_draw_rectangle/p4:x')
+  check_eq(p.y, 41, 'F - test_draw_rectangle/p4:y')
+end
+
+function test_draw_rectangle_intermediate()
+  io.write('\ntest_draw_rectangle_intermediate')
+  -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  App.draw()
+  check_eq(Current_drawing_mode, 'line', 'F - test_draw_rectangle_intermediate/baseline/drawing_mode')
+  check_eq(#Lines, 2, 'F - test_draw_rectangle_intermediate/baseline/#lines')
+  check_eq(Lines[1].mode, 'drawing', 'F - test_draw_rectangle_intermediate/baseline/mode')
+  check_eq(Lines[1].y, Margin_top+Drawing_padding_top, 'F - test_draw_rectangle_intermediate/baseline/y')
+  check_eq(Lines[1].h, 128, 'F - test_draw_rectangle_intermediate/baseline/y')
+  check_eq(#Lines[1].shapes, 0, 'F - test_draw_rectangle_intermediate/baseline/#shapes')
+  -- first point
+  App.run_after_mouse_press(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  App.run_after_keychord('r')  -- rectangle mode
+  -- second point/first edge
+  App.mouse_move(Margin_left+42, Margin_top+Drawing_padding_top+45)
+  App.run_after_keychord('p')
+  -- override second point/first edge
+  App.mouse_move(Margin_left+75, Margin_top+Drawing_padding_top+76)
+  App.run_after_keychord('p')
+  local drawing = Lines[1]
+  check_eq(#drawing.points, 3, 'F - test_draw_rectangle_intermediate/#points')  -- currently includes every point added
+  local pending = drawing.pending
+  check_eq(pending.mode, 'rectangle', 'F - test_draw_rectangle_intermediate/shape_mode')
+  check_eq(#pending.vertices, 2, 'F - test_draw_rectangle_intermediate/vertices')
+  local p = drawing.points[pending.vertices[1]]
+  check_eq(p.x, 35, 'F - test_draw_rectangle_intermediate/p1:x')
+  check_eq(p.y, 36, 'F - test_draw_rectangle_intermediate/p1:y')
+  local p = drawing.points[pending.vertices[2]]
+  check_eq(p.x, 75, 'F - test_draw_rectangle_intermediate/p2:x')
+  check_eq(p.y, 76, 'F - test_draw_rectangle_intermediate/p2:y')
+  -- outline of rectangle is drawn based on where the mouse is, but we can't check that so far
+end
+
+function test_draw_square()
+  io.write('\ntest_draw_square')
+  -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  App.draw()
+  check_eq(Current_drawing_mode, 'line', 'F - test_draw_square/baseline/drawing_mode')
+  check_eq(#Lines, 2, 'F - test_draw_square/baseline/#lines')
+  check_eq(Lines[1].mode, 'drawing', 'F - test_draw_square/baseline/mode')
+  check_eq(Lines[1].y, Margin_top+Drawing_padding_top, 'F - test_draw_square/baseline/y')
+  check_eq(Lines[1].h, 128, 'F - test_draw_square/baseline/y')
+  check_eq(#Lines[1].shapes, 0, 'F - test_draw_square/baseline/#shapes')
+  -- first point
+  App.run_after_mouse_press(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  App.run_after_keychord('s')  -- square mode
+  -- second point/first edge
+  App.mouse_move(Margin_left+42, Margin_top+Drawing_padding_top+45)
+  App.run_after_keychord('p')
+  -- override second point/first edge
+  App.mouse_move(Margin_left+65, Margin_top+Drawing_padding_top+66)
+  App.run_after_keychord('p')
+  -- release (decides which side of first edge to draw square on)
+  App.run_after_mouse_release(Margin_left+15, Margin_top+Drawing_padding_top+26, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 1, 'F - test_draw_square/#shapes')
+  check_eq(#drawing.points, 5, 'F - test_draw_square/#points')  -- currently includes every point added
+  check_eq(drawing.shapes[1].mode, 'square', 'F - test_draw_square/shape_mode')
+  check_eq(#drawing.shapes[1].vertices, 4, 'F - test_draw_square/vertices')
+  local p = drawing.points[drawing.shapes[1].vertices[1]]
+  check_eq(p.x, 35, 'F - test_draw_square/p1:x')
+  check_eq(p.y, 36, 'F - test_draw_square/p1:y')
+  local p = drawing.points[drawing.shapes[1].vertices[2]]
+  check_eq(p.x, 65, 'F - test_draw_square/p2:x')
+  check_eq(p.y, 66, 'F - test_draw_square/p2:y')
+  local p = drawing.points[drawing.shapes[1].vertices[3]]
+  check_eq(p.x, 35, 'F - test_draw_square/p3:x')
+  check_eq(p.y, 96, 'F - test_draw_square/p3:y')
+  local p = drawing.points[drawing.shapes[1].vertices[4]]
+  check_eq(p.x, 5, 'F - test_draw_square/p4:x')
+  check_eq(p.y, 66, 'F - test_draw_square/p4:y')
+end
+
+function test_name_point()
+  io.write('\ntest_name_point')
+  -- create a drawing with a line
+  Filename = 'foo'
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  Current_drawing_mode = 'line'
+  App.draw()
+  -- draw a line
+  App.run_after_mouse_press(Margin_left+5, Margin_top+Drawing_padding_top+6, 1)
+  App.run_after_mouse_release(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 1, 'F - test_name_point/baseline/#shapes')
+  check_eq(#drawing.points, 2, 'F - test_name_point/baseline/#points')
+  check_eq(drawing.shapes[1].mode, 'line', 'F - test_name_point/baseline/shape:1')
+  local p1 = drawing.points[drawing.shapes[1].p1]
+  local p2 = drawing.points[drawing.shapes[1].p2]
+  check_eq(p1.x, 5, 'F - test_name_point/baseline/p1:x')
+  check_eq(p1.y, 6, 'F - test_name_point/baseline/p1:y')
+  check_eq(p2.x, 35, 'F - test_name_point/baseline/p2:x')
+  check_eq(p2.y, 36, 'F - test_name_point/baseline/p2:y')
+  check_nil(p2.name, 'F - test_name_point/baseline/p2:name')
+  -- enter 'name' mode without moving the mouse
+  App.run_after_keychord('C-n')
+  check_eq(Current_drawing_mode, 'name', 'F - test_name_point/mode:1')
+  App.run_after_textinput('A')
+  check_eq(p2.name, 'A', 'F - test_name_point')
+  -- still in 'name' mode
+  check_eq(Current_drawing_mode, 'name', 'F - test_name_point/mode:2')
+  -- exit 'name' mode
+  App.run_after_keychord('return')
+  check_eq(Current_drawing_mode, 'line', 'F - test_name_point/mode:3')
+  check_eq(p2.name, 'A', 'F - test_name_point')
+  -- change is saved
+  Lines = load_from_disk(Filename)
+  local p2 = Lines[1].points[drawing.shapes[1].p2]
+  check_eq(p2.name, 'A', 'F - test_name_point/save')
+end
+
+function test_move_point()
+  io.write('\ntest_move_point')
+  -- create a drawing with a line
+  Filename = 'foo'
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  Current_drawing_mode = 'line'
+  App.draw()
+  App.run_after_mouse_press(Margin_left+5, Margin_top+Drawing_padding_top+6, 1)
+  App.run_after_mouse_release(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 1, 'F - test_move_point/baseline/#shapes')
+  check_eq(#drawing.points, 2, 'F - test_move_point/baseline/#points')
+  check_eq(drawing.shapes[1].mode, 'line', 'F - test_move_point/baseline/shape:1')
+  local p1 = drawing.points[drawing.shapes[1].p1]
+  local p2 = drawing.points[drawing.shapes[1].p2]
+  check_eq(p1.x, 5, 'F - test_move_point/baseline/p1:x')
+  check_eq(p1.y, 6, 'F - test_move_point/baseline/p1:y')
+  check_eq(p2.x, 35, 'F - test_move_point/baseline/p2:x')
+  check_eq(p2.y, 36, 'F - test_move_point/baseline/p2:y')
+  check_nil(p2.name, 'F - test_move_point/baseline/p2:name')
+  -- line is saved to disk
+  Lines = load_from_disk(Filename)
+  local drawing = Lines[1]
+  local p2 = Lines[1].points[drawing.shapes[1].p2]
+  check_eq(p2.x, 35, 'F - test_move_point/save/x')
+  check_eq(p2.y, 36, 'F - test_move_point/save/y')
+  App.draw()
+  -- enter 'move' mode without moving the mouse
+  App.run_after_keychord('C-u')
+  check_eq(Current_drawing_mode, 'move', 'F - test_move_point/mode:1')
+  -- point is lifted
+  check_eq(drawing.pending.mode, 'move', 'F - test_move_point/mode:2')
+  check_eq(drawing.pending.target_point, p2, 'F - test_move_point/target')
+  -- move point
+  App.mouse_move(Margin_left+26, Margin_top+Drawing_padding_top+44)
+  App.update(0.05)
+  local p2 = drawing.points[drawing.shapes[1].p2]
+  check_eq(p2.x, 26, 'F - test_move_point/x')
+  check_eq(p2.y, 44, 'F - test_move_point/y')
+  -- exit 'move' mode
+  App.run_after_mouse_click(Margin_left+26, Margin_top+Drawing_padding_top+44, 1)
+  check_eq(Current_drawing_mode, 'line', 'F - test_move_point/mode:3')
+  check_eq(drawing.pending, {}, 'F - test_move_point/pending')
+  -- change is saved
+  Lines = load_from_disk(Filename)
+  local p2 = Lines[1].points[drawing.shapes[1].p2]
+  check_eq(p2.x, 26, 'F - test_move_point/save/x')
+  check_eq(p2.y, 44, 'F - test_move_point/save/y')
+end
+
+function test_delete_lines_at_point()
+  io.write('\ntest_delete_lines_at_point')
+  -- create a drawing with two lines connected at a point
+  Filename = 'foo'
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  Current_drawing_mode = 'line'
+  App.draw()
+  App.run_after_mouse_press(Margin_left+5, Margin_top+Drawing_padding_top+6, 1)
+  App.run_after_mouse_release(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  App.run_after_mouse_press(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  App.run_after_mouse_release(Margin_left+55, Margin_top+Drawing_padding_top+26, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 2, 'F - test_delete_lines_at_point/baseline/#shapes')
+  check_eq(drawing.shapes[1].mode, 'line', 'F - test_delete_lines_at_point/baseline/shape:1')
+  check_eq(drawing.shapes[2].mode, 'line', 'F - test_delete_lines_at_point/baseline/shape:2')
+  -- hover on the common point and delete
+  App.mouse_move(Margin_left+35, Margin_top+Drawing_padding_top+36)
+  App.run_after_keychord('C-d')
+  check_eq(drawing.shapes[1].mode, 'deleted', 'F - test_delete_lines_at_point/shape:1')
+  check_eq(drawing.shapes[2].mode, 'deleted', 'F - test_delete_lines_at_point/shape:2')
+  -- deleted points disappear after file is reloaded
+  Lines = load_from_disk(Filename)
+  check_eq(#Lines[1].shapes, 0, 'F - test_delete_lines_at_point/save')
+end
+
+function test_delete_line_under_mouse_pointer()
+  io.write('\ntest_delete_line_under_mouse_pointer')
+  -- create a drawing with two lines connected at a point
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  Current_drawing_mode = 'line'
+  App.draw()
+  App.run_after_mouse_press(Margin_left+5, Margin_top+Drawing_padding_top+6, 1)
+  App.run_after_mouse_release(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  App.run_after_mouse_press(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  App.run_after_mouse_release(Margin_left+55, Margin_top+Drawing_padding_top+26, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 2, 'F - test_delete_line_under_mouse_pointer/baseline/#shapes')
+  check_eq(drawing.shapes[1].mode, 'line', 'F - test_delete_line_under_mouse_pointer/baseline/shape:1')
+  check_eq(drawing.shapes[2].mode, 'line', 'F - test_delete_line_under_mouse_pointer/baseline/shape:2')
+  -- hover on one of the lines and delete
+  App.mouse_move(Margin_left+25, Margin_top+Drawing_padding_top+26)
+  App.run_after_keychord('C-d')
+  -- only that line is deleted
+  check_eq(drawing.shapes[1].mode, 'deleted', 'F - test_delete_line_under_mouse_pointer/shape:1')
+  check_eq(drawing.shapes[2].mode, 'line', 'F - test_delete_line_under_mouse_pointer/shape:2')
+end
+
+function test_delete_point_from_polygon()
+  io.write('\ntest_delete_point_from_polygon')
+  -- create a drawing with two lines connected at a point
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  Current_drawing_mode = 'line'
+  App.draw()
+  -- first point
+  App.run_after_mouse_press(Margin_left+5, Margin_top+Drawing_padding_top+6, 1)
+  App.run_after_keychord('g')  -- polygon mode
+  -- second point
+  App.mouse_move(Margin_left+65, Margin_top+Drawing_padding_top+36)
+  App.run_after_keychord('p')  -- add point
+  -- third point
+  App.mouse_move(Margin_left+35, Margin_top+Drawing_padding_top+26)
+  App.run_after_keychord('p')  -- add point
+  -- fourth point
+  App.run_after_mouse_release(Margin_left+14, Margin_top+Drawing_padding_top+16, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 1, 'F - test_delete_point_from_polygon/baseline/#shapes')
+  check_eq(drawing.shapes[1].mode, 'polygon', 'F - test_delete_point_from_polygon/baseline/mode')
+  check_eq(#drawing.shapes[1].vertices, 4, 'F - test_delete_point_from_polygon/baseline/vertices')
+  -- hover on a point and delete
+  App.mouse_move(Margin_left+35, Margin_top+Drawing_padding_top+26)
+  App.run_after_keychord('C-d')
+  -- just the one point is deleted
+  check_eq(drawing.shapes[1].mode, 'polygon', 'F - test_delete_point_from_polygon/shape')
+  check_eq(#drawing.shapes[1].vertices, 3, 'F - test_delete_point_from_polygon/vertices')
+end
+
+function test_delete_point_from_polygon()
+  io.write('\ntest_delete_point_from_polygon')
+  -- create a drawing with two lines connected at a point
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  Current_drawing_mode = 'line'
+  App.draw()
+  -- first point
+  App.run_after_mouse_press(Margin_left+5, Margin_top+Drawing_padding_top+6, 1)
+  App.run_after_keychord('g')  -- polygon mode
+  -- second point
+  App.mouse_move(Margin_left+65, Margin_top+Drawing_padding_top+36)
+  App.run_after_keychord('p')  -- add point
+  -- third point
+  App.run_after_mouse_release(Margin_left+14, Margin_top+Drawing_padding_top+16, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 1, 'F - test_delete_point_from_polygon/baseline/#shapes')
+  check_eq(drawing.shapes[1].mode, 'polygon', 'F - test_delete_point_from_polygon/baseline/mode')
+  check_eq(#drawing.shapes[1].vertices, 3, 'F - test_delete_point_from_polygon/baseline/vertices')
+  -- hover on a point and delete
+  App.mouse_move(Margin_left+65, Margin_top+Drawing_padding_top+36)
+  App.run_after_keychord('C-d')
+  -- there's < 3 points left, so the whole polygon is deleted
+  check_eq(drawing.shapes[1].mode, 'deleted', 'F - test_delete_point_from_polygon')
+end
+
+function test_undo_name_point()
+  io.write('\ntest_undo_name_point')
+  -- create a drawing with a line
+  Filename = 'foo'
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  Current_drawing_mode = 'line'
+  App.draw()
+  -- draw a line
+  App.run_after_mouse_press(Margin_left+5, Margin_top+Drawing_padding_top+6, 1)
+  App.run_after_mouse_release(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 1, 'F - test_undo_name_point/baseline/#shapes')
+  check_eq(#drawing.points, 2, 'F - test_undo_name_point/baseline/#points')
+  check_eq(drawing.shapes[1].mode, 'line', 'F - test_undo_name_point/baseline/shape:1')
+  local p1 = drawing.points[drawing.shapes[1].p1]
+  local p2 = drawing.points[drawing.shapes[1].p2]
+  check_eq(p1.x, 5, 'F - test_undo_name_point/baseline/p1:x')
+  check_eq(p1.y, 6, 'F - test_undo_name_point/baseline/p1:y')
+  check_eq(p2.x, 35, 'F - test_undo_name_point/baseline/p2:x')
+  check_eq(p2.y, 36, 'F - test_undo_name_point/baseline/p2:y')
+  check_nil(p2.name, 'F - test_undo_name_point/baseline/p2:name')
+  check_eq(#History, 1, 'F - test_undo_name_point/baseline/history:1')
+  -- enter 'name' mode without moving the mouse
+  App.run_after_keychord('C-n')
+  App.run_after_textinput('A')
+  App.run_after_keychord('return')
+  check_eq(p2.name, 'A', 'F - test_undo_name_point/baseline')
+  check_eq(#History, 3, 'F - test_undo_name_point/baseline/history:2')
+  check_eq(Next_history, 4, 'F - test_undo_name_point/baseline/next_history')
+  -- undo
+  App.run_after_keychord('C-z')
+  local drawing = Lines[1]
+  local p2 = drawing.points[drawing.shapes[1].p2]
+  check_eq(Next_history, 3, 'F - test_undo_name_point/next_history')
+  check_eq(p2.name, '', 'F - test_undo_name_point')  -- not quite what it was before, but close enough
+  -- undo is saved
+  Lines = load_from_disk(Filename)
+  local p2 = Lines[1].points[drawing.shapes[1].p2]
+  check_eq(p2.name, '', 'F - test_undo_name_point/save')
+end
+
+function test_undo_move_point()
+  io.write('\ntest_undo_move_point')
+  -- create a drawing with a line
+  Filename = 'foo'
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  Current_drawing_mode = 'line'
+  App.draw()
+  App.run_after_mouse_press(Margin_left+5, Margin_top+Drawing_padding_top+6, 1)
+  App.run_after_mouse_release(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 1, 'F - test_undo_move_point/baseline/#shapes')
+  check_eq(#drawing.points, 2, 'F - test_undo_move_point/baseline/#points')
+  check_eq(drawing.shapes[1].mode, 'line', 'F - test_undo_move_point/baseline/shape:1')
+  local p1 = drawing.points[drawing.shapes[1].p1]
+  local p2 = drawing.points[drawing.shapes[1].p2]
+  check_eq(p1.x, 5, 'F - test_undo_move_point/baseline/p1:x')
+  check_eq(p1.y, 6, 'F - test_undo_move_point/baseline/p1:y')
+  check_eq(p2.x, 35, 'F - test_undo_move_point/baseline/p2:x')
+  check_eq(p2.y, 36, 'F - test_undo_move_point/baseline/p2:y')
+  check_nil(p2.name, 'F - test_undo_move_point/baseline/p2:name')
+  -- move p2
+  App.run_after_keychord('C-u')
+  App.mouse_move(Margin_left+26, Margin_top+Drawing_padding_top+44)
+  App.update(0.05)
+  local p2 = drawing.points[drawing.shapes[1].p2]
+  check_eq(p2.x, 26, 'F - test_undo_move_point/x')
+  check_eq(p2.y, 44, 'F - test_undo_move_point/y')
+  -- exit 'move' mode
+  App.run_after_mouse_click(Margin_left+26, Margin_top+Drawing_padding_top+44, 1)
+  check_eq(Next_history, 4, 'F - test_undo_move_point/next_history')
+  -- undo
+  App.run_after_keychord('C-z')
+  App.run_after_keychord('C-z')  -- bug: need to undo twice
+  local drawing = Lines[1]
+  local p2 = drawing.points[drawing.shapes[1].p2]
+  check_eq(Next_history, 2, 'F - test_undo_move_point/next_history')
+  check_eq(p2.x, 35, 'F - test_undo_move_point/x')
+  check_eq(p2.y, 36, 'F - test_undo_move_point/y')
+  -- undo is saved
+  Lines = load_from_disk(Filename)
+  local p2 = Lines[1].points[drawing.shapes[1].p2]
+  check_eq(p2.x, 35, 'F - test_undo_move_point/save/x')
+  check_eq(p2.y, 36, 'F - test_undo_move_point/save/y')
+end
+
+function test_undo_delete_point()
+  io.write('\ntest_undo_delete_point')
+  -- create a drawing with two lines connected at a point
+  Filename = 'foo'
+  App.screen.init{width=Margin_left+300, height=300}
+  Lines = load_array{'```lines', '```', ''}
+  Line_width = 256  -- drawing coordinates 1:1 with pixels
+  Current_drawing_mode = 'line'
+  App.draw()
+  App.run_after_mouse_press(Margin_left+5, Margin_top+Drawing_padding_top+6, 1)
+  App.run_after_mouse_release(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  App.run_after_mouse_press(Margin_left+35, Margin_top+Drawing_padding_top+36, 1)
+  App.run_after_mouse_release(Margin_left+55, Margin_top+Drawing_padding_top+26, 1)
+  local drawing = Lines[1]
+  check_eq(#drawing.shapes, 2, 'F - test_undo_delete_point/baseline/#shapes')
+  check_eq(drawing.shapes[1].mode, 'line', 'F - test_undo_delete_point/baseline/shape:1')
+  check_eq(drawing.shapes[2].mode, 'line', 'F - test_undo_delete_point/baseline/shape:2')
+  -- hover on the common point and delete
+  App.mouse_move(Margin_left+35, Margin_top+Drawing_padding_top+36)
+  App.run_after_keychord('C-d')
+  check_eq(drawing.shapes[1].mode, 'deleted', 'F - test_undo_delete_point/shape:1')
+  check_eq(drawing.shapes[2].mode, 'deleted', 'F - test_undo_delete_point/shape:2')
+  -- undo
+  App.run_after_keychord('C-z')
+  local drawing = Lines[1]
+  local p2 = drawing.points[drawing.shapes[1].p2]
+  check_eq(Next_history, 3, 'F - test_undo_move_point/next_history')
+  check_eq(drawing.shapes[1].mode, 'line', 'F - test_undo_delete_point/shape:1')
+  check_eq(drawing.shapes[2].mode, 'line', 'F - test_undo_delete_point/shape:2')
+  -- undo is saved
+  Lines = load_from_disk(Filename)
+  check_eq(#Lines[1].shapes, 2, 'F - test_undo_delete_point/save')
+end

file.lua

@@ -2,7 +2,7 @@
 Drawing = require 'drawing'
 
 function load_from_disk(filename)
-  local infile = io.open(filename)
+  local infile = App.open_for_reading(filename)
   local result = load_from_file(infile)
   if infile then infile:close() end
   return result

main.lua

@@ -33,7 +33,6 @@ function App.initialize_globals()
 --    an array points for mode 'freehand' (raw x,y coords; freehand drawings don't pollute the points array of a drawing)
 --    an array vertices for mode 'polygon', 'rectangle', 'square'
 --    p1, p2 for mode 'line'
---    p1, p2, arrow-mode for mode 'arrow-line'
 --    center, radius for mode 'circle'
 --    center, radius, start_angle, end_angle for mode 'arc'
 -- Unless otherwise specified, coord fields are normalized; a drawing is always 256 units wide
@@ -66,6 +65,8 @@ Previous_drawing_mode = nil
 -- values for tests
 Font_height = 14
 Line_height = 15
+-- widest possible character width
+Em = App.newText(love.graphics.getFont(), 'm')
 
 Margin_top = 15
 Margin_left = 25
@@ -175,8 +176,9 @@ function initialize_font_settings(font_height)
   love.graphics.setFont(love.graphics.newFont(Font_height))
   Line_height = math.floor(font_height*1.3)
 
-  -- maximum width available to either text or drawings, in pixels
   Em = App.newText(love.graphics.getFont(), 'm')
+
+  -- maximum width available to either text or drawings, in pixels
   -- readable text width is 50-75 chars
   Line_width = math.min(40*App.width(Em), App.screen.width-50)
 end
@@ -407,6 +409,7 @@ function App.keychord_pressed(chord)
       Selection1 = deepcopy(src.selection)
       patch(Lines, event.after, event.before)
       Text.redraw_all()  -- if we're scrolling, reclaim all fragments to avoid memory leaks
+      save_to_disk(Lines, Filename)
     end
   elseif chord == 'C-y' then
     for _,line in ipairs(Lines) do line.y = nil end  -- just in case we scroll
@@ -418,6 +421,7 @@ function App.keychord_pressed(chord)
       Selection1 = deepcopy(src.selection)
       patch(Lines, event.before, event.after)
       Text.redraw_all()  -- if we're scrolling, reclaim all fragments to avoid memory leaks
+      save_to_disk(Lines, Filename)
     end
   -- clipboard
   elseif chord == 'C-c' then

manual_tests

@@ -1,24 +0,0 @@
--- static properties of the code
-All strings are UTF-8. Bytes within them are not characters.
-I try to label byte offsets as _offset, and character positions as _pos.
-For example, string.sub should never use a _pos to substring, only an _offset.
-Wish I had some static typing here. We're not going to try to write tests to catch issues like this.
-
--- manual tests
-drawing
-  draw a line, circle, rectangle, square, polygon
-  select a point and move it
-  select a point and name it
-
-persistence:
-  draw a line, circle, rectangle, square, polygon, quit, restart. All the shapes you drew should still be visible.
-  select a point and name it, quit, restart. Name is still visible.
-
-undo:
-  naming points
-  deleting points
-  moving points
-
-resize:
-  create a file containing a long line of characters without spaces. try
-  resizing the window vertically and horizontally, as far as possible.