feat(parser): add support for Lua 5.4 attributes in global declarations

Author: yeshan333

spec/parser_spec.lua

@@ -580,6 +580,48 @@ describe("parser", function()
       end)
    end)
 
+   describe("when parsing global declarations", function()
+      it("parses global declaration correctly", function()
+         assert.same({tag = "Global", {
+                           {tag = "Id", "a"}
+                        }
+                     }, get_node("global a"))
+         assert.same({tag = "Global", {
+                           {tag = "Id", "a"},
+                           {tag = "Id", "b"}
+                        }
+                     }, get_node("global a, b"))
+      end)
+
+      it("accepts Lua 5.4 attributes on global declarations", function()
+         assert.same({tag = "Global", {
+                           {tag = "Id", "a"}
+                        }
+                     }, get_node("global a <close>"))
+         assert.same({tag = "Global", {
+                           {tag = "Id", "a"},
+                           {tag = "Id", "b"}
+                        }
+                     }, get_node("global a <close>, b <const>"))
+         assert.same({
+            tag = "Global", {
+               {tag = "Id", "a"}
+            }, {
+               {tag = "Id", "b"}
+            }
+         }, get_node("global a <close> = b"))
+         assert.same({
+            tag = "Global", {
+               {tag = "Id", "a"},
+               {tag = "Id", "b"}
+         }, {
+               {tag = "Id", "c"},
+               {tag = "Id", "d"}
+            }
+         }, get_node("global a <close>, b <const> = c, d"))
+      end)
+   end)
+
    describe("when parsing assignments", function()
       it("parses single target assignment correctly", function()
          assert.same({

src/luacheck/parser.lua

@@ -837,6 +837,35 @@ statements["local"] = function(state)
    return new_inner_node(start_range, rhs and rhs[#rhs] or lhs[#lhs], "Local", {lhs, rhs})
 end
 
+statements["global"] = function(state)
+   local start_range = copy_range(state)
+   -- Skip "global".
+   skip_token(state)
+
+   -- Global definition, potentially with assignment.
+   local lhs = {}
+   local rhs
+
+   repeat
+      lhs[#lhs + 1] = parse_id(state)
+
+      -- Check if a Lua 5.4/5.5 attribute is present
+      if state.token == "<" then
+         -- Consume and ignore attribute for now
+         skip_token(state)
+         check_name(state)
+         skip_token(state)
+         check_and_skip_token(state, ">")
+      end
+   until not test_and_skip_token(state, ",")
+
+   if test_and_skip_token(state, "=") then
+      rhs = parse_expression_list(state)
+   end
+
+   return new_inner_node(start_range, rhs and rhs[#rhs] or lhs[#lhs], "Global", {lhs, rhs})
+end
+
 statements["::"] = function(state)
    local start_range = copy_range(state)
    -- Skip "::".