Show doc urls for extension cops

RuboCop 1.64 added support for passing in a config, which will then construct
the correct url for non-buildin departments that have `DocumentationBaseURL` set.

lib/ruby_lsp/requests/support/rubocop_diagnostic.rb

@@ -19,6 +19,16 @@ class RuboCopDiagnostic
           T::Hash[Symbol, Integer],
         )
 
+        ENHANCED_DOC_URL = T.let(
+          begin
+            gem("rubocop", ">= 1.64.0")
+            true
+          rescue LoadError
+            false
+          end,
+          T::Boolean,
+        )
+
         # TODO: avoid passing document once we have alternative ways to get at
         # encoding and file source
         sig { params(document: Document, offense: RuboCop::Cop::Offense, uri: URI::Generic).void }
@@ -38,16 +48,16 @@ def to_lsp_code_actions
           code_actions
         end
 
-        sig { returns(Interface::Diagnostic) }
-        def to_lsp_diagnostic
+        sig { params(config: RuboCop::Config).returns(Interface::Diagnostic) }
+        def to_lsp_diagnostic(config)
           # highlighted_area contains the begin and end position of the first line
           # This ensures that multiline offenses don't clutter the editor
           highlighted = @offense.highlighted_area
           Interface::Diagnostic.new(
             message: message,
             source: "RuboCop",
             code: @offense.cop_name,
-            code_description: code_description,
+            code_description: code_description(config),
             severity: severity,
             range: Interface::Range.new(
               start: Interface::Position.new(
@@ -80,9 +90,16 @@ def severity
           RUBOCOP_TO_LSP_SEVERITY[@offense.severity.name]
         end
 
-        sig { returns(T.nilable(Interface::CodeDescription)) }
-        def code_description
-          doc_url = RuboCopRunner.find_cop_by_name(@offense.cop_name)&.documentation_url
+        sig { params(config: RuboCop::Config).returns(T.nilable(Interface::CodeDescription)) }
+        def code_description(config)
+          cop = RuboCopRunner.find_cop_by_name(@offense.cop_name)
+          return unless cop
+
+          doc_url = if ENHANCED_DOC_URL
+            cop.documentation_url(config)
+          else
+            cop.documentation_url
+          end
           Interface::CodeDescription.new(href: doc_url) if doc_url
         end
 

lib/ruby_lsp/requests/support/rubocop_formatter.rb

@@ -38,7 +38,11 @@ def run_diagnostic(uri, document)
           @diagnostic_runner.run(filename, document.source)
 
           @diagnostic_runner.offenses.map do |offense|
-            Support::RuboCopDiagnostic.new(document, offense, uri).to_lsp_diagnostic
+            Support::RuboCopDiagnostic.new(
+              document,
+              offense,
+              uri,
+            ).to_lsp_diagnostic(@diagnostic_runner.config_for_working_directory)
           end
         end
       end

lib/ruby_lsp/requests/support/rubocop_runner.rb

@@ -50,6 +50,9 @@ class ConfigurationError < StandardError; end
         sig { returns(T::Array[RuboCop::Cop::Offense]) }
         attr_reader :offenses
 
+        sig { returns(::RuboCop::Config) }
+        attr_reader :config_for_working_directory
+
         DEFAULT_ARGS = T.let(
           [
             "--stderr", # Print any output to stderr so that our stdout does not get polluted
@@ -78,6 +81,7 @@ def initialize(*args)
           args += DEFAULT_ARGS
           rubocop_options = ::RuboCop::Options.new.parse(args).first
           config_store = ::RuboCop::ConfigStore.new
+          @config_for_working_directory = T.let(config_store.for_pwd, ::RuboCop::Config)
 
           super(rubocop_options, config_store)
         end

test/expectations/diagnostics/rubocop_extension_cop.exp.json

@@ -0,0 +1,100 @@
+{
+  "result": [
+    {
+      "range": {
+        "start": {
+          "line": 5,
+          "character": 4
+        },
+        "end": {
+          "line": 5,
+          "character": 25
+        }
+      },
+      "severity": 3,
+      "code": "Minitest/AssertEmptyLiteral",
+      "codeDescription": {
+        "href": "https://docs.rubocop.org/rubocop-minitest/cops_minitest.html#minitestassertemptyliteral"
+      },
+      "source": "RuboCop",
+      "message": "Minitest/AssertEmptyLiteral: Prefer using `assert_empty(foo)`.",
+      "data": {
+        "correctable": true,
+        "code_actions": [
+          {
+            "title": "Autocorrect Minitest/AssertEmptyLiteral",
+            "kind": "quickfix",
+            "isPreferred": true,
+            "edit": {
+              "documentChanges": [
+                {
+                  "textDocument": {
+                    "uri": "file:///fake",
+                    "version": null
+                  },
+                  "edits": [
+                    {
+                      "range": {
+                        "start": {
+                          "line": 5,
+                          "character": 4
+                        },
+                        "end": {
+                          "line": 5,
+                          "character": 16
+                        }
+                      },
+                      "newText": "assert_empty"
+                    },
+                    {
+                      "range": {
+                        "start": {
+                          "line": 5,
+                          "character": 17
+                        },
+                        "end": {
+                          "line": 5,
+                          "character": 24
+                        }
+                      },
+                      "newText": "foo"
+                    }
+                  ]
+                }
+              ]
+            }
+          },
+          {
+            "title": "Disable Minitest/AssertEmptyLiteral for this line",
+            "kind": "quickfix",
+            "edit": {
+              "documentChanges": [
+                {
+                  "textDocument": {
+                    "uri": "file:///fake",
+                    "version": null
+                  },
+                  "edits": [
+                    {
+                      "range": {
+                        "start": {
+                          "line": 5,
+                          "character": 25
+                        },
+                        "end": {
+                          "line": 5,
+                          "character": 25
+                        }
+                      },
+                      "newText": " # rubocop:disable Minitest/AssertEmptyLiteral"
+                    }
+                  ]
+                }
+              ]
+            }
+          }
+        ]
+      }
+    }
+  ]
+}

test/fixtures/rubocop_extension_cop.rb

@@ -0,0 +1,8 @@
+# typed: true
+# frozen_string_literal: true
+
+class ExampleTest < Minitest::Test
+  def test_public
+    assert_equal([], foo)
+  end
+end