Implement RSpec one-liner helpers

- is_expected
- should
- shuld_not

CHANGELOG.md

@@ -20,6 +20,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
     <img src="./doc/images/3rd_party_matchers.png" width="600" alt="3rd party matchers completion">
     </details>
 
+- Implement RSpec [one-liner syntax](https://rspec.info/features/3-12/rspec-core/subject/one-liner-syntax/) helpers: `is_expected`, `should` and `should_not`
+  - <details><summary>📹</summary>
+    <img src="./doc/images/one_liners_demo.gif" width="600" alt="One-liner syntax completion">
+    </details>
 
 ## v0.3.0 - 2024-07-10
 

lib/solargraph/rspec/correctors/subject_method_corrector.rb

@@ -16,14 +16,19 @@ def correct(_source_map)
 
             subject_pin = rspec_subject_method(namespace_pin, subject_name, location_range, fake_method_ast)
             add_pin(subject_pin)
+            add_pins(one_liner_expecation_pins(subject_pin))
           end
 
           rspec_walker.after_walk do
             next unless described_class_pin
 
             namespace_pin = closest_namespace_pin(namespace_pins, described_class_pin.location.range.start.line)
 
-            add_pin(implicit_subject_pin(described_class_pin, namespace_pin)) if namespace_pin
+            if namespace_pin
+              implicit_subject_pin = implicit_subject_method(described_class_pin, namespace_pin)
+              add_pin(implicit_subject_pin)
+              add_pins(one_liner_expecation_pins(implicit_subject_pin))
+            end
           end
         end
 
@@ -47,7 +52,7 @@ def rspec_subject_method(namespace_pin, subject_name, location_range, fake_metho
         # @param described_class_pin [Pin::Method]
         # @param namespace_pin [Pin::Namespace]
         # @return [Pin::Method]
-        def implicit_subject_pin(described_class_pin, namespace_pin)
+        def implicit_subject_method(described_class_pin, namespace_pin)
           described_class = described_class_pin.return_type.first.subtypes.first.name
 
           PinFactory.build_public_method(
@@ -58,6 +63,41 @@ def implicit_subject_pin(described_class_pin, namespace_pin)
             scope: :instance
           )
         end
+
+        # @param subject_pin [Pin::Method]
+        # @return [Array<Pin::Method>]
+        def one_liner_expecation_pins(subject_pin)
+          [
+            one_liner_expecation_pin(subject_pin.closure, :is_expected, subject_pin.location),
+            one_liner_expecation_pin(subject_pin.closure, :should, subject_pin.location),
+            one_liner_expecation_pin(subject_pin.closure, :should_not, subject_pin.location)
+          ]
+        end
+
+        # @param namespace_pin [Pin::Namespace]
+        # @param method_name [:is_expected, :should, :should_not]
+        # @param location [Solargraph::Location]
+        # @return [Pin::Method]
+        def one_liner_expecation_pin(namespace_pin, method_name, location)
+          return_type = case method_name
+                        when :is_expected
+                          ['::RSpec::Expectations::ExpectationTarget']
+                        when :should
+                          ['::RSpec::Matchers::BuiltIn::PositiveOperatorMatcher']
+                        when :should_not
+                          ['::RSpec::Matchers::BuiltIn::NegativeOperatorMatcher']
+                        else
+                          raise ArgumentError, "Unknown inline expectation method: #{method_name}"
+                        end
+
+          PinFactory.build_public_method(
+            namespace_pin,
+            method_name.to_s,
+            types: [return_type],
+            location: location,
+            scope: :instance
+          )
+        end
       end
     end
   end

spec/solargraph/rspec/convention_spec.rb

@@ -95,6 +95,39 @@
     expect(completion_at(filename, [22, 8])).to include('nested_something')
   end
 
+  # @see https://rspec.info/features/3-12/rspec-core/subject/one-liner-syntax/
+  it 'generates method for one-liner expectations' do
+    load_string filename, <<~RUBY
+      RSpec.describe SomeNamespace::Transaction, type: :model do
+        subject(:transaction) { described_class.new }
+
+        it { is_expected.to be_a(SomeNamespace::Transaction) }
+        it { should be_a(SomeNamespace::Transaction) }
+        it { should_not be_a(String)  }
+      end
+    RUBY
+
+    subject_location = { start: { line: 1, character: 2 }, end: { line: 1, character: 23 } }
+
+    assert_public_instance_method(
+      api_map,
+      'RSpec::ExampleGroups::TestSomeNamespaceTransaction#is_expected',
+      ['RSpec::Expectations::ExpectationTarget']
+    ) { |pin| expect(pin.location.range.to_hash).to eq(subject_location) }
+
+    assert_public_instance_method(
+      api_map,
+      'RSpec::ExampleGroups::TestSomeNamespaceTransaction#should',
+      ['RSpec::Matchers::BuiltIn::PositiveOperatorMatcher']
+    ) { |pin| expect(pin.location.range.to_hash).to eq(subject_location) }
+
+    assert_public_instance_method(
+      api_map,
+      'RSpec::ExampleGroups::TestSomeNamespaceTransaction#should_not',
+      ['RSpec::Matchers::BuiltIn::NegativeOperatorMatcher']
+    ) { |pin| expect(pin.location.range.to_hash).to eq(subject_location) }
+  end
+
   it 'generates let methods with do/end block' do
     load_string filename, <<~RUBY
       RSpec.describe SomeNamespace::Transaction, type: :model do