[Fix rubocop#50] Make EndWith/StartWith autocorrects nil-safe

CHANGELOG.md

@@ -2,11 +2,15 @@
 
 ## master (unreleased)
 
+### Bug fixes
+
+* [#50](https://github.com/rubocop-hq/rubocop-performance/issues/50): Make `Performance/EndWith` and `Performance/StartWith` autocorrects nil-safe. ([@dduugg][])
+
 ## 1.3.0 (2019-05-13)
 
 ### Bug fixes
 
-* [#48](https://github.com/rubocop-hq/rubocop-performance/issues/48): Reduce `Performance/RegexpMatch` false positive by only flagging `match` used with Regexp/String/Symbol literals. ([@dduugg][])
+* [#48](https://github.com/rubocop-hq/rubocop-performance/issues/48): Reduce `Performance/RegexpMatch` false positives by only flagging `match` used with Regexp/String/Symbol literals. ([@dduugg][])
 
 ### Changes
 

config/default.yml

@@ -82,7 +82,6 @@ Performance/EndWith:
  # object. Switching these methods has to be done with knowledge of the types
  # of the variables which rubocop doesn't have.
  SafeAutoCorrect: false
- AutoCorrect: false
  Enabled: true
  VersionAdded: '0.36'
  VersionChanged: '0.44'
@@ -176,7 +175,6 @@ Performance/StartWith:
  # object. Switching these methods has to be done with knowledge of the types
  # of the variables which rubocop doesn't have.
  SafeAutoCorrect: false
- AutoCorrect: false
  Enabled: true
  VersionAdded: '0.36'
  VersionChanged: '0.44'

lib/rubocop/cop/performance/end_with.rb

@@ -44,7 +44,7 @@ def autocorrect(node)
  regex_str = interpret_string_escapes(regex_str)
 
  lambda do |corrector|
- new_source = receiver.source + '.end_with?(' +
+ new_source = receiver.source + '&.end_with?(' +
  to_string_literal(regex_str) + ')'
  corrector.replace(node.source_range, new_source)
  end

lib/rubocop/cop/performance/start_with.rb

@@ -47,7 +47,7 @@ def autocorrect(node)
  regex_str = interpret_string_escapes(regex_str)
 
  lambda do |corrector|
- new_source = receiver.source + '.start_with?(' +
+ new_source = receiver.source + '&.start_with?(' +
  to_string_literal(regex_str) + ')'
  corrector.replace(node.source_range, new_source)
  end

manual/cops_performance.md

@@ -324,7 +324,7 @@ would suffice.
 
 Name | Default value | Configurable values
 --- | --- | ---
-AutoCorrect | `false` | Boolean
+AutoCorrect | `true` | Boolean
 
 ### References
 
@@ -775,7 +775,7 @@ This cop identifies unnecessary use of a regex where
 
 Name | Default value | Configurable values
 --- | --- | ---
-AutoCorrect | `false` | Boolean
+AutoCorrect | `true` | Boolean
 
 ### References
 

spec/rubocop/cop/performance/end_with_spec.rb

@@ -6,23 +6,23 @@
  shared_examples 'different match methods' do |method|
  it "autocorrects #{method} /abc\\z/" do
  new_source = autocorrect_source("str#{method} /abc\\z/")
- expect(new_source).to eq "str.end_with?('abc')"
+ expect(new_source).to eq "str&.end_with?('abc')"
  end
 
  it "autocorrects #{method} /\\n\\z/" do
  new_source = autocorrect_source("str#{method} /\\n\\z/")
- expect(new_source).to eq 'str.end_with?("\n")'
+ expect(new_source).to eq 'str&.end_with?("\n")'
  end
 
  it "autocorrects #{method} /\\t\\z/" do
  new_source = autocorrect_source("str#{method} /\\t\\z/")
- expect(new_source).to eq 'str.end_with?("\t")'
+ expect(new_source).to eq 'str&.end_with?("\t")'
  end
 
  %w[. $ ^ |].each do |str|
  it "autocorrects #{method} /\\#{str}\\z/" do
  new_source = autocorrect_source("str#{method} /\\#{str}\\z/")
- expect(new_source).to eq "str.end_with?('#{str}')"
+ expect(new_source).to eq "str&.end_with?('#{str}')"
  end
 
  it "doesn't register an error for #{method} /#{str}\\z/" do
@@ -36,7 +36,7 @@
  %w[a e f r t v].each do |str|
  it "autocorrects #{method} /\\#{str}\\z/" do
  new_source = autocorrect_source("str#{method} /\\#{str}\\z/")
- expect(new_source).to eq %{str.end_with?("\\#{str}")}
+ expect(new_source).to eq %{str&.end_with?("\\#{str}")}
  end
  end
 
@@ -51,7 +51,7 @@
  %w[i j l m o q y].each do |str|
  it "autocorrects #{method} /\\#{str}\\z/" do
  new_source = autocorrect_source("str#{method} /\\#{str}\\z/")
- expect(new_source).to eq "str.end_with?('#{str}')"
+ expect(new_source).to eq "str&.end_with?('#{str}')"
  end
  end
 
@@ -64,7 +64,7 @@
 
  it "autocorrects #{method} /\\\\\\z/" do
  new_source = autocorrect_source("str#{method} /\\\\\\z/")
- expect(new_source).to eq("str.end_with?('\\\\')")
+ expect(new_source).to eq("str&.end_with?('\\\\')")
  end
  end
 

spec/rubocop/cop/performance/start_with_spec.rb

@@ -6,7 +6,7 @@
  shared_examples 'different match methods' do |method|
  it "autocorrects #{method} /\\Aabc/" do
  new_source = autocorrect_source("str#{method} /\\Aabc/")
- expect(new_source).to eq "str.start_with?('abc')"
+ expect(new_source).to eq "str&.start_with?('abc')"
  end
 
  # escapes like "\n"
@@ -15,15 +15,15 @@
  %w[a e f r t v].each do |str|
  it "autocorrects #{method} /\\A\\#{str}/" do
  new_source = autocorrect_source("str#{method} /\\A\\#{str}/")
- expect(new_source).to eq %{str.start_with?("\\#{str}")}
+ expect(new_source).to eq %{str&.start_with?("\\#{str}")}
  end
  end
 
  # regexp metacharacters
  %w[. * ? $ ^ |].each do |str|
  it "autocorrects #{method} /\\A\\#{str}/" do
  new_source = autocorrect_source("str#{method} /\\A\\#{str}/")
- expect(new_source).to eq "str.start_with?('#{str}')"
+ expect(new_source).to eq "str&.start_with?('#{str}')"
  end
 
  it "doesn't register an error for #{method} /\\A#{str}/" do
@@ -42,7 +42,7 @@
  %w[i j l m o q y].each do |str|
  it "autocorrects #{method} /\\A\\#{str}/" do
  new_source = autocorrect_source("str#{method} /\\A\\#{str}/")
- expect(new_source).to eq "str.start_with?('#{str}')"
+ expect(new_source).to eq "str&.start_with?('#{str}')"
  end
  end
 
@@ -55,7 +55,7 @@
 
  it "autocorrects #{method} /\\A\\\\/" do
  new_source = autocorrect_source("str#{method} /\\A\\\\/")
- expect(new_source).to eq("str.start_with?('\\\\')")
+ expect(new_source).to eq("str&.start_with?('\\\\')")
  end
  end