Merge pull request rubocop#2750 from Drenmi/bugfix/no-method-error-in…

…-guard-clause-cop

[Fix rubocop#2723] Fix NoMethodError in Style/GuardClause cop

CHANGELOG.md

@@ -10,6 +10,7 @@
 
 ### Bug fixes
 
+* [#2723](https://github.com/bbatsov/rubocop/issues/2723): Fix NoMethodError in Style/GuardClause. ([@drenmi][])
 * [#2674](https://github.com/bbatsov/rubocop/issues/2674): Also check for Hash#update alias in `Performance/RedundantMerge`. ([@drenmi][])
 * [#2630](https://github.com/bbatsov/rubocop/issues/2630): Take frozen string literals into account in `Style/MutableConstant`. ([@segiddins][])
 * [#2642](https://github.com/bbatsov/rubocop/issues/2642): Support assignment via `||=` in `Style/MutableConstant`. ([@segiddins][])

lib/rubocop/cop/style/guard_clause.rb

@@ -112,8 +112,9 @@ def line_too_long_when_corrected?(node)
         def line_too_long?(node, body, keyword, condition)
           max    = config.for_cop('Metrics/LineLength')['Max'] || 80
           indent = node.loc.column
+          source = body && body.source || ''
           # 2 is for spaces on left and right of keyword
-          indent + (body.source + keyword + condition.source).length + 2 > max
+          indent + (source + keyword + condition.source).length + 2 > max
         end
       end
     end

spec/rubocop/cop/style/guard_clause_spec.rb

@@ -7,50 +7,76 @@
   let(:cop) { described_class.new(config) }
   let(:cop_config) { {} }
 
-  it 'reports an offense if method body is if / unless without else' do
-    inspect_source(cop,
-                   ['def func',
-                    '  if something',
-                    '    work',
-                    '  end',
-                    'end',
-                    '',
-                    'def func',
-                    '  unless something',
-                    '    work',
-                    '  end',
-                    'end'])
-    expect(cop.offenses.size).to eq(2)
-    expect(cop.offenses.map(&:line).sort).to eq([2, 8])
-    expect(cop.messages)
-      .to eq(['Use a guard clause instead of wrapping ' \
-              'the code inside a conditional expression.'] * 2)
-    expect(cop.highlights).to eq(%w(if unless))
-  end
+  shared_examples 'reports offense' do |body|
+    it 'reports an offense if method body is if / unless without else' do
+      inspect_source(cop,
+                     ['def func',
+                      '  if something',
+                      "    #{body}",
+                      '  end',
+                      'end',
+                      '',
+                      'def func',
+                      '  unless something',
+                      "    #{body}",
+                      '  end',
+                      'end'])
+      expect(cop.offenses.size).to eq(2)
+      expect(cop.offenses.map(&:line).sort).to eq([2, 8])
+      expect(cop.messages)
+        .to eq(['Use a guard clause instead of wrapping ' \
+                'the code inside a conditional expression.'] * 2)
+      expect(cop.highlights).to eq(%w(if unless))
+    end
 
-  it 'reports an offense if method body ends with if / unless without else' do
-    inspect_source(cop,
-                   ['def func',
-                    '  test',
-                    '  if something',
-                    '    work',
-                    '  end',
-                    'end',
-                    '',
-                    'def func',
-                    '  test',
-                    '  unless something',
-                    '    work',
-                    '  end',
-                    'end'])
-    expect(cop.offenses.size).to eq(2)
-    expect(cop.offenses.map(&:line).sort).to eq([3, 10])
-    expect(cop.messages)
-      .to eq(['Use a guard clause instead of wrapping ' \
-              'the code inside a conditional expression.'] * 2)
-    expect(cop.highlights).to eq(%w(if unless))
+    it 'reports an offense if method body is if / unless without else' do
+      inspect_source(cop,
+                     ['def func',
+                      '  if something',
+                      "    #{body}",
+                      '  end',
+                      'end',
+                      '',
+                      'def func',
+                      '  unless something',
+                      "    #{body}",
+                      '  end',
+                      'end'])
+      expect(cop.offenses.size).to eq(2)
+      expect(cop.offenses.map(&:line).sort).to eq([2, 8])
+      expect(cop.messages)
+        .to eq(['Use a guard clause instead of wrapping ' \
+                'the code inside a conditional expression.'] * 2)
+      expect(cop.highlights).to eq(%w(if unless))
+    end
+
+    it 'reports an offense if method body ends with if / unless without else' do
+      inspect_source(cop,
+                     ['def func',
+                      '  test',
+                      '  if something',
+                      "    #{body}",
+                      '  end',
+                      'end',
+                      '',
+                      'def func',
+                      '  test',
+                      '  unless something',
+                      "    #{body}",
+                      '  end',
+                      'end'])
+      expect(cop.offenses.size).to eq(2)
+      expect(cop.offenses.map(&:line).sort).to eq([3, 10])
+      expect(cop.messages)
+        .to eq(['Use a guard clause instead of wrapping ' \
+                'the code inside a conditional expression.'] * 2)
+      expect(cop.highlights).to eq(%w(if unless))
+    end
   end
 
+  it_behaves_like('reports offense', 'work')
+  it_behaves_like('reports offense', '# TODO')
+
   it 'does not report an offense if corrected code would exceed line length' do
     inspect_source(cop,
                    ['def func',