type_checkers: css definition

Author: krishpranav

src/type_checkers/css_definition.cr

@@ -0,0 +1,62 @@
+# -----------------------------------------------------------------------
+# This file is part of MoonScript
+#
+# MoonSript is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# MoonSript is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with MoonSript.  If not, see <https://www.gnu.org/licenses/>.
+#
+# Copyright (C) 2025 Krisna Pranav, MoonScript Developers
+# -----------------------------------------------------------------------
+
+module MoonScript
+    class TypeChecker
+      CSS_PROPERTY_NAMES =
+        {{ read_file("#{__DIR__}/../assets/css_properties").strip.lines }}
+  
+      def check(node : Ast::CssDefinition) : Checkable
+        node.value.each do |item|
+          type =
+            case item
+            when Ast::Node
+              resolve item
+            else
+              STRING
+            end
+  
+          unless node.name.starts_with?('-')
+            error! :css_definition_no_property do
+              block do
+                text "There is no CSS property with the name:"
+                bold %("#{node.name}")
+              end
+  
+              snippet node
+            end unless CSS_PROPERTY_NAMES.includes?(node.name)
+          end
+  
+          error! :css_definition_type_mismatch do
+            block do
+              text "The type of the value for the CSS property"
+              bold %("#{node.name}")
+              text "is invalid."
+            end
+  
+            snippet "expecting one of these types:", "String\nNumber"
+            snippet "Instead it is:", type
+            snippet "The css definition in question is here:", node
+          end unless Comparer.matches_any?(type, [STRING, NUMBER])
+        end
+  
+        VOID
+      end
+    end
+  end