Port audit_desc rules to cop

1 files changed, 67 insertions, 0 deletions

diff --git a/Library/Homebrew/rubocops/formula_desc_cop.rb b/Library/Homebrew/rubocops/formula_desc_cop.rb
new file mode 100644
index 000000000..8728c6fc0
--- /dev/null
+++ b/Library/Homebrew/rubocops/formula_desc_cop.rb
@@ -0,0 +1,67 @@
+module RuboCop
+  module Cop
+    module Homebrew
+      class FormulaDesc < Cop
+        def on_class(node)
+          class_node, parent_class_node, body = *node
+          formula_name = class_node.const_name
+          return unless parent_class_node && parent_class_node.const_name == "Formula" && body
+          check(node, body, formula_name)
+        end
+
+        private
+
+        def check(node, body, formula_name)
+          body.each_child_node(:send) do |call_node|
+            _receiver, call_name, args = *call_node
+            next unless call_name == :desc && !args.children[0].empty?
+            description = args.children[0]
+
+            source_buffer = call_node.source_range.source_buffer
+            line_number = call_node.loc.line
+            line_begin_pos = call_node.source_range.source_buffer.line_range(call_node.loc.line).begin_pos
+            desc_begin_pos = call_node.children[2].source_range.begin_pos
+
+            linelength = "#{formula_name}: #{description}".length
+            if linelength > 80
+              column = desc_begin_pos - line_begin_pos
+              length = call_node.children[2].source_range.size
+              sourcerange = source_range(source_buffer, line_number, column, length)
+              message = <<-EOS.strip_indent
+                        Description is too long. \"name: desc\" should be less than 80 characters.
+                        Length is calculated as #{formula_name} + desc. (currently #{linelength})
+                        EOS
+              add_offense(call_node, sourcerange, message)
+            end
+
+            match_object = description.match(/([Cc]ommand ?line)/)
+            if match_object
+              column = desc_begin_pos+match_object.begin(0)-line_begin_pos+1
+              length = match_object.to_s.length
+              sourcerange = source_range(source_buffer, line_number, column, length)
+              add_offense(call_node, sourcerange, "Description should use \"command-line\" instead of \"#{match_object}\"")
+            end
+
+            match_object = description.match(/^([Aa]n?)\s/)
+            if match_object
+              column = desc_begin_pos+match_object.begin(0)-line_begin_pos+1
+              length = match_object.to_s.length
+              sourcerange = source_range(source_buffer, line_number, column, length)
+              add_offense(call_node, sourcerange, "Description shouldn't start with an indefinite article (#{match_object})")
+            end
+
+            match_object = description.match(/^#{formula_name}/i)
+            if match_object
+              column = desc_begin_pos+match_object.begin(0)-line_begin_pos+1
+              length = match_object.to_s.length
+              sourcerange = source_range(source_buffer, line_number, column, length)
+              add_offense(call_node, sourcerange, "Description shouldn't include the formula name")
+            end
+            return
+          end
+          add_offense(node, node.source_range, "Formula should have a desc (Description).")
+        end
+      end
+    end
+  end
+end