Extend matcher support in ExpectActual auto-correct

Author: pirj

CHANGELOG.md

@@ -4,7 +4,7 @@
 
 * Fix `RSpec/InstanceVariable` detection inside custom matchers. ([@pirj][])
 * Fix `RSpec/ScatteredSetup` to distinguish hooks with different metadata. ([@pirj][])
-* Add autocorrect support for `RSpec/ExpectActual` cop. ([@dduugg][])
+* Add autocorrect support for `RSpec/ExpectActual` cop. ([@dduugg][], [@pirj][])
 
 ## 1.37.1 (2019-12-16)
 

lib/rubocop/cop/rspec/expect_actual.rb

@@ -41,11 +41,16 @@ class ExpectActual < Cop
           regexp
         ].freeze
 
+        SUPPORTED_MATCHERS = %i[eq eql equal be].freeze
+
         def_node_matcher :expect_literal, <<~PATTERN
           (send
             (send nil? :expect $#literal?)
             #{Runners::ALL.node_pattern_union}
-            $(send nil? ...)
+            {
+              (send (send nil? $:be) :== $_)
+              (send nil? $_ $_ ...)
+            }
           )
         PATTERN
 
@@ -56,11 +61,11 @@ def on_send(node)
         end
 
         def autocorrect(node)
-          argument, matcher = expect_literal(node)
+          actual, matcher, expected = expect_literal(node)
           lambda do |corrector|
-            return if matcher.method_name != :eq
+            return unless SUPPORTED_MATCHERS.include?(matcher)
 
-            swap(corrector, argument, matcher.arguments.first)
+            swap(corrector, actual, expected)
           end
         end
 

spec/rubocop/cop/rspec/expect_actual_spec.rb

@@ -207,7 +207,93 @@
     RUBY
   end
 
-  it 'flags but does not autocorrect violations without eq' do
+  it 'ignores `be` with no argument' do
+    expect_no_offenses(<<~RUBY)
+      describe Foo do
+        it 'uses expect legitimately' do
+          expect(1).to be
+        end
+      end
+    RUBY
+  end
+
+  it 'flags `be` with an argument' do
+    expect_offense(<<~RUBY)
+      describe Foo do
+        it 'uses expect incorrectly' do
+          expect(true).to be(a)
+                 ^^^^ Provide the actual you are testing to `expect(...)`.
+        end
+      end
+    RUBY
+
+    expect_correction(<<~RUBY)
+      describe Foo do
+        it 'uses expect incorrectly' do
+          expect(a).to be(true)
+        end
+      end
+    RUBY
+  end
+
+  it 'flags `be ==`' do
+    expect_offense(<<~RUBY)
+      describe Foo do
+        it 'uses expect incorrectly' do
+          expect(1).to be == a
+                 ^ Provide the actual you are testing to `expect(...)`.
+        end
+      end
+    RUBY
+
+    expect_correction(<<~RUBY)
+      describe Foo do
+        it 'uses expect incorrectly' do
+          expect(a).to be == 1
+        end
+      end
+    RUBY
+  end
+
+  it 'flags with `eql` matcher' do
+    expect_offense(<<-RUBY)
+      describe Foo do
+        it 'uses expect incorrectly' do
+          expect(1).to eql(bar)
+                 ^ Provide the actual you are testing to `expect(...)`.
+        end
+      end
+    RUBY
+
+    expect_correction(<<-RUBY)
+      describe Foo do
+        it 'uses expect incorrectly' do
+          expect(bar).to eql(1)
+        end
+      end
+    RUBY
+  end
+
+  it 'flags with `equal` matcher' do
+    expect_offense(<<-RUBY)
+      describe Foo do
+        it 'uses expect incorrectly' do
+          expect(1).to equal(bar)
+                 ^ Provide the actual you are testing to `expect(...)`.
+        end
+      end
+    RUBY
+
+    expect_correction(<<-RUBY)
+      describe Foo do
+        it 'uses expect incorrectly' do
+          expect(bar).to equal(1)
+        end
+      end
+    RUBY
+  end
+
+  it 'flags but does not autocorrect violations for other matchers' do
     expect_offense(<<-RUBY)
       describe Foo do
         it 'uses expect incorrectly' do