[Fix rubocop#719] Allow using arrays, variables and method in receive_message_chain

Maxim Krizhanovski · Maxim Krizhanovski · commit 3520077051f7 · 2018-12-27T17:58:58.000+02:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -5,6 +5,7 @@
 * Add `IgnoreSharedExamples` option for `RSpec/NamedSubject`. ([@RST-J][])
 * Add autocorrect support for `Capybara/CurrentPathExpectation` cop. ([@ypresto][])
 * Add support for built-in `exists` matcher for `RSpec/PredicateMatcher` cop. ([@mkenyon][])
+* `SingleArgumentMessageChain` no longer reports an array as it's only argument as an offense. ([@Darhazer][])
 
 ## 1.30.1 (2018-11-01)
 
diff --git a/lib/rubocop/cop/rspec/single_argument_message_chain.rb b/lib/rubocop/cop/rspec/single_argument_message_chain.rb
@@ -26,9 +26,7 @@ class SingleArgumentMessageChain < Cop
 
         def on_send(node)
           message_chain(node) do |arg|
-            return if arg.to_s.include?('.')
-
-            return if arg.hash_type? && !single_key_hash?(arg)
+            return if valid_usage?(arg)
 
             add_offense(node, location: :selector)
           end
@@ -39,12 +37,27 @@ def autocorrect(node)
             corrector.replace(node.loc.selector, replacement(node.method_name))
             message_chain(node) do |arg|
               autocorrect_hash_arg(corrector, arg) if single_key_hash?(arg)
+              autocorrect_array_arg(corrector, arg) if arg.array_type?
             end
           end
         end
 
         private
 
+        def valid_usage?(node)
+          return true unless node.literal? || node.array_type?
+
+          case node.type
+          when :hash then !single_key_hash?(node)
+          when :array then !single_element_array?(node)
+          else node.to_s.include?('.')
+          end
+        end
+
+        def single_element_array?(node)
+          node.child_nodes.one?
+        end
+
         def autocorrect_hash_arg(corrector, arg)
           key, value = *arg.children.first
 
@@ -53,6 +66,12 @@ def autocorrect_hash_arg(corrector, arg)
                                  ".and_return(#{value.source})")
         end
 
+        def autocorrect_array_arg(corrector, arg)
+          value = arg.children.first
+
+          corrector.replace(arg.loc.expression, value.source)
+        end
+
         def key_to_arg(node)
           key, = *node
           node.sym_type? ? ":#{key}" : node.source
diff --git a/spec/rubocop/cop/rspec/single_argument_message_chain_spec.rb b/spec/rubocop/cop/rspec/single_argument_message_chain_spec.rb
@@ -48,8 +48,52 @@
       RUBY
     end
 
+    it 'accepts single-argument calls with variable' do
+      expect_no_offenses(<<-RUBY)
+        before do
+          foo = %i[:one :two]
+          allow(foo).to receive_message_chain(foo) { :many }
+        end
+      RUBY
+    end
+
+    it 'accepts single-argument calls with send node' do
+      expect_no_offenses(<<-RUBY)
+        before do
+          allow(foo).to receive_message_chain(foo) { :many }
+        end
+      RUBY
+    end
+
+    context 'with single-element array argument' do
+      it 'reports an offense' do
+        expect_offense(<<-RUBY)
+          before do
+            allow(foo).to receive_message_chain([:one]) { :two }
+                          ^^^^^^^^^^^^^^^^^^^^^ Use `receive` instead of calling `receive_message_chain` with a single argument.
+          end
+        RUBY
+      end
+
+      include_examples(
+        'autocorrect',
+        'before { allow(foo).to receive_message_chain([:one]) { :two } }',
+        'before { allow(foo).to receive(:one) { :two } }'
+      )
+    end
+
+    context 'with multiple-element array argument' do
+      it "doesn't report an offense" do
+        expect_no_offenses(<<-RUBY)
+          before do
+            allow(foo).to receive_message_chain([:one, :two]) { :many }
+          end
+        RUBY
+      end
+    end
+
     context 'with single-key hash argument' do
-      it 'reports an offence' do
+      it 'reports an offense' do
         expect_offense(<<-RUBY)
           before do
             allow(foo).to receive_message_chain(bar: 42)
@@ -78,7 +122,7 @@
     end
 
     context 'with multiple keys hash argument' do
-      it "doesn't report an offence" do
+      it "doesn't report an offense" do
         expect_no_offenses(<<-RUBY)
           before do
             allow(foo).to receive_message_chain(bar: 42, baz: 42)
