[Fix rubocop#2232] Fix false positive in Lint/FormatParameterMismatch for

dreyks · dreyks · commit ab7694a273e9 · 2015-09-11T21:50:19.000+03:00
argument with splat operator
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## master (unreleased)
 
+### Bug fixes
+
+* [#2232](https://github.com/bbatsov/rubocop/issues/2232): Fix false positive in `Lint/FormatParameterMismatch` for argument with splat operator. ([@dreyks][])
+
 ## 0.34.1 (09/09/2015)
 
 ### Bug Fixes
@@ -1599,3 +1603,4 @@
 [@imtayadeway]: https://github.com/imtayadeway
 [@mrfoto]: https://github.com/mrfoto
 [@karreiro]: https://github.com/karreiro
+[@dreyks]: https://github.com/dreyks
diff --git a/lib/rubocop/cop/lint/format_parameter_mismatch.rb b/lib/rubocop/cop/lint/format_parameter_mismatch.rb
@@ -30,7 +30,7 @@ def on_send(node)
 
         def offending_node?(node)
           if sprintf?(node) || format?(node) || percent?(node)
-            if named_mode?(node)
+            if named_mode?(node) || node_with_splat_args?(node)
               false
             else
               num_of_args_for_format, num_of_expected_fields = count_matches(node)
@@ -57,6 +57,14 @@ def named_mode?(node)
             .scan(NAMED_FIELD_REGEX).count > 0
         end
 
+        def node_with_splat_args?(node)
+          return false if percent?(node)
+
+          _receiver_node, _method_name, *args = *node
+
+          args[1..-1].any? { |arg| arg.type == :splat }
+        end
+
         def heredoc?(node)
           _receiver, _name, args = *node
 
diff --git a/spec/rubocop/cop/lint/format_parameter_mismatch_spec.rb b/spec/rubocop/cop/lint/format_parameter_mismatch_spec.rb
@@ -119,6 +119,16 @@
     expect(cop.offenses.size).to eq(1)
   end
 
+  it 'does not register an offense for sprintf with splat argument' do
+    inspect_source(cop, 'sprintf("%d%d", *test)')
+    expect(cop.offenses).to be_empty
+  end
+
+  it 'does not register an offense for format with splat argument' do
+    inspect_source(cop, 'format("%d%d", *test)')
+    expect(cop.offenses).to be_empty
+  end
+
   it 'finds the correct number of fields' do
     expect(''.scan(cop.fields_regex).size)
       .to eq(0)
