Deprecate ConstantNameInspector#constant_name_from_node without relat…

…ive_file:

lib/packwerk/reference_extractor.rb

@@ -80,8 +80,9 @@ def reference_from_node(node, ancestors:, relative_file:)
       constant_name = T.let(nil, T.nilable(String))
 
       @constant_name_inspectors.each do |inspector|
-        constant_name = inspector.constant_name_from_node(
-          node,
+        constant_name = inspect_node(
+          inspector,
+          node: node,
           ancestors: ancestors,
           relative_file: relative_file
         )
@@ -101,6 +102,29 @@ def reference_from_node(node, ancestors:, relative_file:)
 
     private
 
+    sig do
+      params(
+        inspector: ConstantNameInspector,
+        node: Parser::AST::Node,
+        ancestors: T::Array[Parser::AST::Node],
+        relative_file: String
+      ).returns(T.nilable(String))
+    end
+    def inspect_node(inspector, node:, ancestors:, relative_file:)
+      inspector.constant_name_from_node(node, ancestors: ancestors, relative_file: relative_file)
+    rescue ArgumentError => error
+      if error.message == "unknown keyword: :relative_file"
+        T.unsafe(inspector).constant_name_from_node(node, ancestors: ancestors).tap do
+          warn(<<~MSG.squish)
+            #{T.cast(inspector, Object).class}#reference_from_node without a relative_file: keyword
+            argument is deprecated and will be required in Packwerk 3.1.1.
+          MSG
+        end
+      else
+        raise
+      end
+    end
+
     sig do
       params(
         constant_name: String,

test/unit/packwerk/reference_extractor_test.rb

@@ -211,6 +211,21 @@ def teardown
       assert_equal "::Order", reference.constant.name
     end
 
+    test "constant name inspector without file name kwarg is deprecated but works" do
+      _, error_output = capture_io do
+        process(
+          ":orders",
+          "components/timeline/app/models/entry.rb",
+          [DeprecatedInspector.new],
+        )
+      end
+
+      assert_equal(<<~MSG.squish, error_output.chomp)
+        Packwerk::ReferenceExtractorTest::DeprecatedInspector#reference_from_node without
+        a relative_file: keyword argument is deprecated and will be required in Packwerk 3.1.1.
+      MSG
+    end
+
     private
 
     class DummyAssociationInspector
@@ -235,6 +250,14 @@ def constant_name_from_node(node, ancestors:, relative_file:)
       end
     end
 
+    class DeprecatedInspector
+      T.unsafe(self).include(ConstantNameInspector)
+
+      def constant_name_from_node(node, ancestors:)
+        "Something"
+      end
+    end
+
     DEFAULT_INSPECTORS = [ConstNodeInspector.new, DummyAssociationInspector.new]
 
     def process(code, file_path, constant_name_inspectors = DEFAULT_INSPECTORS)