feat(treesitter)!: use @foo.bar style highlight groups

This removes the support for defining links via
vim.treesitter.highlighter.hl_map (never documented, but plugins did
anyway), or the uppercase-only `@FooGroup.Bar` to `FooGroup` rule.

The fallback is now strictly `@foo.bar.lang` to `@foo.bar` to `@foo`,
and casing is irrelevant (as it already was outside of treesitter)

For compatibility, define default links to builting syntax groups
as defined by pre-existing color schemes

1 files changed, 60 insertions, 36 deletions

diff --git a/test/functional/treesitter/highlight_spec.lua b/test/functional/treesitter/highlight_spec.lua
index 5ec0a8a060..e4ef975d34 100644
--- a/test/functional/treesitter/highlight_spec.lua
+++ b/test/functional/treesitter/highlight_spec.lua
@@ -6,11 +6,14 @@ local insert = helpers.insert
 local exec_lua = helpers.exec_lua
 local feed = helpers.feed
 local pending_c_parser = helpers.pending_c_parser
+local command = helpers.command
+local meths = helpers.meths
+local eq = helpers.eq
 
 before_each(clear)
 
 local hl_query = [[
-  (ERROR) @ErrorMsg
+  (ERROR) @error
 
   "if" @keyword
   "else" @keyword
@@ -23,23 +26,24 @@ local hl_query = [[
   "enum" @type
   "extern" @type
 
-  (string_literal) @string.nonexistent-specializer-for-string.should-fallback-to-string
+  ; nonexistent specializer for string should fallback to string
+  (string_literal) @string.nonexistent_specializer
 
   (number_literal) @number
   (char_literal) @string
 
   (type_identifier) @type
-  ((type_identifier) @Special (#eq? @Special "LuaRef"))
+  ((type_identifier) @constant.builtin (#eq? @constant.builtin "LuaRef"))
 
   (primitive_type) @type
   (sized_type_specifier) @type
 
   ; Use lua regexes
-  ((identifier) @Identifier (#contains? @Identifier "lua_"))
+  ((identifier) @function (#contains? @function "lua_"))
   ((identifier) @Constant (#lua-match? @Constant "^[A-Z_]+$"))
-  ((identifier) @Normal (#vim-match? @Constant "^lstate$"))
+  ((identifier) @Normal (#vim-match? @Normal "^lstate$"))
 
-  ((binary_expression left: (identifier) @WarningMsg.left right: (identifier) @WarningMsg.right) (#eq? @WarningMsg.left @WarningMsg.right))
+  ((binary_expression left: (identifier) @warning.left right: (identifier) @warning.right) (#eq? @warning.left @warning.right))
 
   (comment) @comment
 ]]
@@ -103,6 +107,7 @@ describe('treesitter highlighting', function()
     }
 
     exec_lua([[ hl_query = ... ]], hl_query)
+    command [[ hi link @warning WarningMsg ]]
   end)
 
   it('is updated with edits', function()
@@ -547,7 +552,7 @@ describe('treesitter highlighting', function()
 
     -- This will change ONLY the literal strings to look like comments
     -- The only literal string is the "vim.schedule: expected function" in this test.
-    exec_lua [[vim.cmd("highlight link cString comment")]]
+    exec_lua [[vim.cmd("highlight link @string.nonexistent_specializer comment")]]
     screen:expect{grid=[[
       {2:/// Schedule Lua callback on main loop's event queue}             |
       {3:static} {3:int} {11:nlua_schedule}({3:lua_State} *{3:const} lstate)                |
@@ -642,11 +647,13 @@ describe('treesitter highlighting', function()
                                                                        |
     ]]}
 
+    command [[
+      hi link @foo.bar Type
+      hi link @foo String
+    ]]
     exec_lua [[
       local parser = vim.treesitter.get_parser(0, "c", {})
       local highlighter = vim.treesitter.highlighter
-      highlighter.hl_map['foo.bar'] = 'Type'
-      highlighter.hl_map['foo'] = 'String'
       test_hl = highlighter.new(parser, {queries = {c = "(primitive_type) @foo.bar (string_literal) @foo"}})
     ]]
 
@@ -670,6 +677,29 @@ describe('treesitter highlighting', function()
       {1:~                                                                }|
                                                                        |
     ]]}
+
+    -- clearing specialization reactivates fallback
+    command [[ hi clear @foo.bar ]]
+    screen:expect{grid=[[
+      {5:char}* x = {5:"Will somebody ever read this?"};                       |
+      ^                                                                 |
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+      {1:~                                                                }|
+                                                                       |
+    ]]}
   end)
 
   it("supports conceal attribute", function()
@@ -712,32 +742,26 @@ describe('treesitter highlighting', function()
     ]]}
   end)
 
-  it("hl_map has the correct fallback behavior", function()
-    exec_lua [[
-      local hl_map = vim.treesitter.highlighter.hl_map
-      hl_map["foo"] = 1
-      hl_map["foo.bar"] = 2
-      hl_map["foo.bar.baz"] = 3
-
-      assert(hl_map["foo"] == 1)
-      assert(hl_map["foo.a.b.c.d"] == 1)
-      assert(hl_map["foo.bar"] == 2)
-      assert(hl_map["foo.bar.a.b.c.d"] == 2)
-      assert(hl_map["foo.bar.baz"] == 3)
-      assert(hl_map["foo.bar.baz.d"] == 3)
-
-      hl_map["FOO"] = 1
-      hl_map["FOO.BAR"] = 2
-      assert(hl_map["FOO.BAR.BAZ"] == 2)
-
-      hl_map["foo.missing.exists"] = 3
-      assert(hl_map["foo.missing"] == 1)
-      assert(hl_map["foo.missing.exists"] == 3)
-      assert(hl_map["foo.missing.exists.bar"] == 3)
-      assert(hl_map["total.nonsense.but.a.lot.of.dots"] == nil)
-      -- It will not perform a second look up of this variable but return a sentinel value
-      assert(hl_map["total.nonsense.but.a.lot.of.dots"] == "__notfound")
-    ]]
-
+  it("@foo.bar groups has the correct fallback behavior", function()
+    local get_hl = function(name) return meths.get_hl_by_name(name,1).foreground end
+    meths.set_hl(0, "@foo", {fg = 1})
+    meths.set_hl(0, "@foo.bar", {fg = 2})
+    meths.set_hl(0, "@foo.bar.baz", {fg = 3})
+
+    eq(1, get_hl"@foo")
+    eq(1, get_hl"@foo.a.b.c.d")
+    eq(2, get_hl"@foo.bar")
+    eq(2, get_hl"@foo.bar.a.b.c.d")
+    eq(3, get_hl"@foo.bar.baz")
+    eq(3, get_hl"@foo.bar.baz.d")
+
+    -- lookup is case insensitive
+    eq(2, get_hl"@FOO.BAR.SPAM")
+
+    meths.set_hl(0, "@foo.missing.exists", {fg = 3})
+    eq(1, get_hl"@foo.missing")
+    eq(3, get_hl"@foo.missing.exists")
+    eq(3, get_hl"@foo.missing.exists.bar")
+    eq(nil, get_hl"@total.nonsense.but.a.lot.of.dots")
   end)
 end)