fix(Color): don't use shared global state

Fixes: #362

Author: tmillr

lua/github-theme/group/modules/treesitter.lua

@@ -8,7 +8,7 @@ function M.get(spec, config, _opts)
   --       being integrated.
   local primitives = require(
     'github-theme.palette.primitives.'
-      .. require('github-theme.config').theme
+      .. spec.palette.meta.name
         :gsub('^github_(.-)_default$', '%1')
         :gsub('^github_(.-)$', '%1')
   )

lua/github-theme/palette/github_dark.lua

@@ -14,9 +14,10 @@ local scale = primitives.scale
 C.WHITE = C(scale.white)
 C.BLACK = C(scale.black)
 C.BG = C(scale.gray[7])
+local BG = C(scale.gray[7])
 
 local function alpha(color, a)
-  return color:alpha_blend(a):to_css()
+  return BG:blend(color, a):to_css()
 end
 
 local palette = {

lua/github-theme/palette/github_dark_colorblind.lua

@@ -14,9 +14,10 @@ local scale = primitives.scale
 C.WHITE = C(scale.white)
 C.BLACK = C(scale.black)
 C.BG = C(assert(primitives.canvas.default))
+local BG = C(assert(primitives.canvas.default))
 
 local function alpha(color, a)
-  return color:alpha_blend(a):to_css()
+  return BG:blend(color, a):to_css()
 end
 
 local palette = {

lua/github-theme/palette/github_dark_default.lua

@@ -13,9 +13,10 @@ local scale = primitives.scale
 C.WHITE = C(scale.white)
 C.BLACK = C(scale.black)
 C.BG = C(assert(primitives.canvas.default))
+local BG = C(assert(primitives.canvas.default))
 
 local function alpha(color, a)
-  return color:alpha_blend(a):to_css()
+  return BG:blend(color, a):to_css()
 end
 
 local palette = {

lua/github-theme/palette/github_dark_dimmed.lua

@@ -14,9 +14,10 @@ local scale = primitives.scale
 C.WHITE = C(scale.white)
 C.BLACK = C(scale.black)
 C.BG = C(assert(primitives.canvas.default))
+local BG = C(assert(primitives.canvas.default))
 
 local function alpha(color, a)
-  return color:alpha_blend(a):to_css()
+  return BG:blend(color, a):to_css()
 end
 
 local palette = {

lua/github-theme/palette/github_dark_high_contrast.lua

@@ -14,9 +14,10 @@ local scale = primitives.scale
 C.WHITE = C(scale.white)
 C.BLACK = C(scale.black)
 C.BG = C(assert(primitives.canvas.default))
+local BG = C(assert(primitives.canvas.default))
 
 local function alpha(color, a)
-  return color:alpha_blend(a):to_css()
+  return BG:blend(color, a):to_css()
 end
 
 local palette = {

lua/github-theme/palette/github_dark_tritanopia.lua

@@ -14,9 +14,10 @@ local scale = primitives.scale
 C.WHITE = C(scale.white)
 C.BLACK = C(scale.black)
 C.BG = C(assert(primitives.canvas.default))
+local BG = C(assert(primitives.canvas.default))
 
 local function alpha(color, a)
-  return color:alpha_blend(a):to_css()
+  return BG:blend(color, a):to_css()
 end
 
 local palette = {

lua/github-theme/palette/github_light.lua

@@ -14,9 +14,10 @@ local scale = primitives.scale
 C.WHITE = C(scale.white)
 C.BLACK = C(scale.black)
 C.BG = C(scale.white)
+local BG = C(scale.white)
 
 local function alpha(color, a)
-  return color:alpha_blend(a):to_css()
+  return BG:blend(color, a):to_css()
 end
 
 -- Temp override until Primitives are updated

lua/github-theme/palette/github_light_colorblind.lua

@@ -14,9 +14,10 @@ local scale = primitives.scale
 C.WHITE = C(scale.white)
 C.BLACK = C(scale.black)
 C.BG = C(assert(primitives.canvas.default))
+local BG = C(assert(primitives.canvas.default))
 
 local function alpha(color, a)
-  return color:alpha_blend(a):to_css()
+  return BG:blend(color, a):to_css()
 end
 
 -- Temp override until Primitives are updated

lua/github-theme/palette/github_light_default.lua

@@ -13,9 +13,10 @@ local scale = primitives.scale
 C.WHITE = C(scale.white)
 C.BLACK = C(scale.black)
 C.BG = C(assert(primitives.canvas.default))
+local BG = C(assert(primitives.canvas.default))
 
 local function alpha(color, a)
-  return color:alpha_blend(a):to_css()
+  return BG:blend(color, a):to_css()
 end
 
 -- Temp override until Primitives are updated

lua/github-theme/palette/github_light_high_contrast.lua

@@ -14,9 +14,10 @@ local scale = primitives.scale
 C.WHITE = C(scale.white)
 C.BLACK = C(scale.black)
 C.BG = C(assert(primitives.canvas.default))
+local BG = C(assert(primitives.canvas.default))
 
 local function alpha(color, a)
-  return color:alpha_blend(a):to_css()
+  return BG:blend(color, a):to_css()
 end
 
 -- Temp override until Primitives are updated

lua/github-theme/palette/github_light_tritanopia.lua

@@ -14,9 +14,10 @@ local scale = primitives.scale
 C.WHITE = C(scale.white)
 C.BLACK = C(scale.black)
 C.BG = C(assert(primitives.canvas.default))
+local BG = C(assert(primitives.canvas.default))
 
 local function alpha(color, a)
-  return color:alpha_blend(a):to_css()
+  return BG:blend(color, a):to_css()
 end
 
 -- Temp override until Primitives are updated

test/github-theme/color_spec.lua

@@ -224,15 +224,15 @@ describe('Color', function()
     end)
   end)
 
-  describe('global state `Color.{WHITE,BLACK,BG}`', function()
+  describe('global fields/state `Color.{WHITE,BLACK,BG}`', function()
     local theme = 'github_dark_dimmed'
     before_each(function()
       require('github-theme.util.reload')(true)
       vim.g.github_theme_force_compile = true
     end)
 
     -- See #362
-    it('should not disrupt palette/spec', function()
+    it('should not disrupt colors in palette/spec/groups', function()
       local groups_expected = require('github-theme.group').load(theme)
       require('github-theme.util.reload')(true)
 
@@ -256,7 +256,7 @@ describe('Color', function()
 
       local function index(_, k)
         if k == 'BG' or k == 'WHITE' or k == 'BLACK' then
-          error(debug.traceback('Color.' .. k .. ' was accessed internally'))
+          error('Color.' .. k .. ' was accessed internally', 2)
         end
         return rawget(C --[[@as table]], k)
       end