api/vim: allow guis and tests to retrieve the entire color table

src/nvim/api/vim.c

@@ -552,6 +552,18 @@ Integer vim_name_to_color(String name)
   return name_to_color((uint8_t *)name.data);
 }
 
+Dictionary vim_get_color_map(void)
+{
+  Dictionary colors = ARRAY_DICT_INIT;
+
+  for (int i = 0; color_name_table[i].name != NULL; i++) {
+    PUT(colors, color_name_table[i].name,
+        INTEGER_OBJ(color_name_table[i].color));
+  }
+  return colors;
+}
+
+
 Array vim_get_api_info(uint64_t channel_id)
 {
   Array rv = ARRAY_DICT_INIT;

src/nvim/syntax.c

@@ -7645,14 +7645,8 @@ char_u *get_highlight_name(expand_T *xp, int idx)
   return HL_TABLE()[idx].sg_name;
 }
 
-
-RgbValue name_to_color(uint8_t *name)
-{
 #define RGB(r, g, b) ((r << 16) | (g << 8) | b)
-  static struct {
-    char *name;
-    RgbValue color;
-  } color_name_table[] = {
+color_name_table_T color_name_table[] = {
   // Color names taken from
   // http://www.rapidtables.com/web/color/RGB_Color.htm
   {"Maroon", RGB(0x80, 0x00, 0x00)},
@@ -7822,7 +7816,10 @@ RgbValue name_to_color(uint8_t *name)
   {"Gray90", RGB(0xe5, 0xe5, 0xe5)},
   {"Grey90", RGB(0xe5, 0xe5, 0xe5)},
   {NULL, 0},
-  };
+};
+
+RgbValue name_to_color(uint8_t *name)
+{
 
   if (name[0] == '#' && isxdigit(name[1]) && isxdigit(name[2])
       && isxdigit(name[3]) && isxdigit(name[4]) && isxdigit(name[5])

src/nvim/syntax.h

@@ -38,6 +38,12 @@
 #define HL_CONCEAL     0x20000 /* can be concealed */
 #define HL_CONCEALENDS 0x40000 /* can be concealed */
 
+typedef struct {
+  char *name;
+  RgbValue color;
+} color_name_table_T;
+extern color_name_table_T color_name_table[];
+
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "syntax.h.generated.h"
 #endif

test/functional/ui/highlight_spec.lua

@@ -29,14 +29,12 @@ end)
 describe('Default highlight groups', function()
   -- Test the default attributes for highlight groups shown by the :highlight
   -- command
-  local screen, hlgroup_colors
+  local screen
 
-  setup(function()
-    hlgroup_colors = {
-      NonText = nvim('name_to_color', 'Blue'),
-      Question = nvim('name_to_color', 'SeaGreen')
+  local hlgroup_colors = {
+    NonText = Screen.colors.Blue,
+    Question = Screen.colors.SeaGreen
   }
-  end)
 
   before_each(function()
     clear()

test/functional/ui/mouse_spec.lua

@@ -4,14 +4,12 @@ local clear, feed, nvim = helpers.clear, helpers.feed, helpers.nvim
 local insert, execute = helpers.insert, helpers.execute
 
 describe('Mouse input', function()
-  local screen, hlgroup_colors
+  local screen
 
-  setup(function()
-    hlgroup_colors = {
-      NonText = nvim('name_to_color', 'Blue'),
-      Visual = nvim('name_to_color', 'LightGrey'),
+  local hlgroup_colors = {
+    NonText = Screen.colors.Blue,
+    Visual = Screen.colors.LightGrey
   }
-  end)
 
   before_each(function()
     clear()

test/functional/ui/screen.lua

@@ -65,7 +65,7 @@
 -- attribute(which normally is), here's how the call to "expect" should look
 -- like:
 --
---     NonText = nvim('name_to_color', 'Blue'),
+--     NonText = Screen.colors.Blue
 --     screen:expect([[
 --       hello screen             \
 --       ~                        \
@@ -86,7 +86,7 @@
 --
 -- Multiple expect:s will likely share a group of attribute sets to test.
 -- Therefore these could be specified at the beginning of a test like this:
---    NonText = nvim('name_to_color', 'Blue')
+--    NonText = Screen.colors.Blue
 --    screen:set_default_attr_ids( {
 --      [1] = {reverse = true, bold = true},
 --      [2] = {reverse = true}
@@ -119,6 +119,16 @@ if os.getenv('VALGRIND') then
   default_screen_timeout = 7500
 end
 
+local colors = request('vim_get_color_map')
+local colornames = {}
+for name, rgb in pairs(colors) do
+    -- we disregard the case that colornames might not be unique, as
+    -- this is just a helper to get any canonical name of a color
+    colornames[rgb] = name
+end
+
+Screen.colors = colors
+
 function Screen.debug(command)
   if not command then
     command = 'pynvim -n -g -c '
@@ -479,7 +489,13 @@ end
 function pprint_attrs(attrs)
     local items = {}
     for f, v in pairs(attrs) do
-      table.insert(items, f.." = "..tostring(v))
+      local desc = tostring(v)
+      if f == "foreground" or f == "background" then
+        if colornames[v] ~= nil then
+          desc = "Screen.colors."..colornames[v]
+        end
+      end
+      table.insert(items, f.." = "..desc)
     end
     return table.concat(items, ", ")
 end