Merge pull request #4618 from DomT4/desc_tweaks

formula_desc_cop: add unnecessary whitespace check

Library/Homebrew/rubocops/formula_desc_cop.rb

@@ -38,6 +38,7 @@ module RuboCop
     module FormulaAuditStrict
       # This cop audits `desc` in Formulae
       #
+      # - Checks for leading/trailing whitespace in `desc`
       # - Checks if `desc` begins with an article
       # - Checks for correct usage of `command-line` in `desc`
       # - Checks description starts with a capital letter
@@ -62,6 +63,16 @@ module RuboCop
 
           desc = parameters(desc_call).first
 
+          # Check for leading whitespace.
+          if regex_match_group(desc, /^\s+/)
+            problem "Description shouldn't have a leading space"
+          end
+
+          # Check for trailing whitespace.
+          if regex_match_group(desc, /\s+$/)
+            problem "Description shouldn't have a trailing space"
+          end
+
           # Check if command-line is wrongly used in formula's desc
           if match = regex_match_group(desc, /(command ?line)/i)
             c = match.to_s.chars.first
@@ -104,6 +115,8 @@ module RuboCop
             correction.gsub!(/^(['"]?)\s+/, "\\1")
             correction.gsub!(/\s+(['"]?)$/, "\\1")
             correction.gsub!(/\.(['"]?)$/, "\\1")
+            correction.gsub!(/^\s+/, "")
+            correction.gsub!(/\s+$/, "")
             corrector.insert_before(node.source_range, correction)
             corrector.remove(node.source_range)
           end

Library/Homebrew/test/rubocops/formula_desc_cop_spec.rb

@@ -65,7 +65,7 @@ describe RuboCop::Cop::FormulaAuditStrict::Desc do
       expect_offense(<<~RUBY, "/homebrew-core/Formula/foo.rb")
         class Foo < Formula
           url 'http://example.com/foo-1.0.tgz'
-          desc 'An '
+          desc 'An aardvark'
                 ^^^ Description shouldn\'t start with an indefinite article i.e. \"An\"
         end
       RUBY
@@ -101,6 +101,26 @@ describe RuboCop::Cop::FormulaAuditStrict::Desc do
       RUBY
     end
 
+    it "When the description starts with a leading space" do
+      expect_offense(<<~RUBY, "/homebrew-core/Formula/foo.rb")
+        class Foo < Formula
+          url 'http://example.com/foo-1.0.tgz'
+          desc ' Description with a leading space'
+                ^ Description shouldn\'t have a leading space
+        end
+      RUBY
+    end
+
+    it "When the description ends with a trailing space" do
+      expect_offense(<<~RUBY, "/homebrew-core/Formula/foo.rb")
+        class Foo < Formula
+          url 'http://example.com/foo-1.0.tgz'
+          desc 'Description with a trailing space '
+                                                 ^ Description shouldn\'t have a trailing space
+        end
+      RUBY
+    end
+
     it "autocorrects all rules" do
       source = <<~RUBY
         class Foo < Formula