Add Lint/NoSemanticInformation

src/ameba/rule/lint/no_semantic_information.cr

@@ -0,0 +1,37 @@
+module Ameba::Rule::Lint
+  # A rule that reports when there's no semantic information available for a given type.
+  # This usually happens when there's a file in the codebase not covered by an entrypoint.
+  #
+  # YAML configuration example:
+  #
+  # ```
+  # Lint/NoSemanticInformation:
+  #   Enabled: true
+  # ```
+  class NoSemanticInformation < Base
+    properties do
+      since_version "1.7.0"
+      description "Reports types that don't have any semantic information available"
+      severity :warning
+    end
+
+    MSG = "This type doesn't have any semantic information (double check the ameba entrypoints)"
+
+    def test(source, context : SemanticContext?)
+      return if context.nil?
+
+      AST::SemanticVisitor.new self, source, context
+    end
+
+    def test(
+      source,
+      node : Crystal::ClassDef | Crystal::ModuleDef |
+             Crystal::LibDef | Crystal::EnumDef,
+      current_type : Crystal::Type,
+    )
+      return if current_type.lookup_type?(node.name)
+
+      issue_for node.name, MSG
+    end
+  end
+end