From a0e6a6f8e72d415740b67f7d80b7d155d34c3bd7 Mon Sep 17 00:00:00 2001
From: Marc-Andre Lafortune <github@marc-andre.ca>
Date: Sat, 18 Jul 2020 01:45:11 -0400
Subject: [PATCH] Fix LambdaNode (modern)

---
 lib/rubocop/ast/node/lambda_node.rb | 11 ++++++++---
 spec/rubocop/ast/lambda_spec.rb     | 19 +++++++++++++++++++
 2 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100644 spec/rubocop/ast/lambda_spec.rb

diff --git a/lib/rubocop/ast/node/lambda_node.rb b/lib/rubocop/ast/node/lambda_node.rb
index b6d697cb0..ce7b72a22 100644
--- a/lib/rubocop/ast/node/lambda_node.rb
+++ b/lib/rubocop/ast/node/lambda_node.rb
@@ -21,7 +21,7 @@ module AST
     # The main RuboCop runs in legacy mode; this node is only used
     # if user `AST::Builder.modernize` or `AST::Builder.emit_lambda=true`
     class LambdaNode < Node
-      include ParameterizedNode
+      include ParameterizedTrailNode
       include MethodDispatchNode
 
       # For similarity with legacy mode
@@ -44,14 +44,19 @@ def assignment_method?
         false
       end
 
+      # For similarity with legacy mode
+      def receiver
+        nil
+      end
+
       # For similarity with legacy mode
       def method_name
         :lambda
       end
 
       # For similarity with legacy mode
-      def arguments
-        []
+      def first_argument_index
+        2
       end
     end
   end
diff --git a/spec/rubocop/ast/lambda_spec.rb b/spec/rubocop/ast/lambda_spec.rb
new file mode 100644
index 000000000..aa7082a3b
--- /dev/null
+++ b/spec/rubocop/ast/lambda_spec.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+# Note: specs for `lambda?` and `lambda_literal?` in `send_node_spec`
+RSpec.describe RuboCop::AST::LambdaNode do
+  let(:source) { '->(a, b) { a + b }' }
+  subject(:lambda_node) { parse_source(source).ast }
+
+  describe '#receiver' do
+    it { expect(lambda_node.receiver).to eq nil }
+  end
+
+  describe '#method_name' do
+    it { expect(lambda_node.method_name).to eq :lambda }
+  end
+
+  describe '#arguments' do
+    it { expect(lambda_node.arguments.size).to eq 2 }
+  end
+end