Add discover tests custom request (#3180)

Add discover tests custom request (#3180)

### Motivation

Closes #3171

Add a new custom request to discover tests in a specific document. This request will instantiate all listeners and collect all of the discovered groups and examples as test items for the editor.

### Implementation

- Created the new request
- Implement a listener dedicated to the test style syntax only (spec will be a separate listener)
- Ensured to use ancestor linearization to determine the test framework

### Automated Tests

Added tests.

Co-authored-by: vinistock <[email protected]>

lib/ruby_lsp/internal.rb

@@ -24,6 +24,7 @@
 require "fileutils"
 require "open3"
 require "securerandom"
+require "shellwords"
 
 require "ruby-lsp"
 require "ruby_lsp/base_server"
@@ -72,6 +73,7 @@
 require "ruby_lsp/requests/completion"
 require "ruby_lsp/requests/definition"
 require "ruby_lsp/requests/diagnostics"
+require "ruby_lsp/requests/discover_tests"
 require "ruby_lsp/requests/document_highlight"
 require "ruby_lsp/requests/document_link"
 require "ruby_lsp/requests/document_symbol"

lib/ruby_lsp/listeners/test_style.rb

@@ -0,0 +1,166 @@
+# typed: strict
+# frozen_string_literal: true
+
+module RubyLsp
+  module Listeners
+    class TestStyle
+      extend T::Sig
+      include Requests::Support::Common
+
+      ACCESS_MODIFIERS = [:public, :private, :protected].freeze
+      DYNAMIC_REFERENCE_MARKER = "<dynamic_reference>"
+
+      sig do
+        params(
+          response_builder: ResponseBuilders::TestCollection,
+          global_state: GlobalState,
+          dispatcher: Prism::Dispatcher,
+          uri: URI::Generic,
+        ).void
+      end
+      def initialize(response_builder, global_state, dispatcher, uri)
+        @response_builder = response_builder
+        @global_state = global_state
+        @uri = uri
+        @index = T.let(global_state.index, RubyIndexer::Index)
+
+        @visibility_stack = T.let([:public], T::Array[Symbol])
+        @nesting = T.let([], T::Array[String])
+
+        dispatcher.register(
+          self,
+          :on_class_node_enter,
+          :on_class_node_leave,
+          :on_module_node_enter,
+          :on_module_node_leave,
+          :on_def_node_enter,
+          :on_call_node_enter,
+          :on_call_node_leave,
+        )
+      end
+
+      sig { params(node: Prism::ClassNode).void }
+      def on_class_node_enter(node)
+        @visibility_stack << :public
+        name = constant_name(node.constant_path)
+        name ||= name_with_dynamic_reference(node.constant_path)
+
+        fully_qualified_name = RubyIndexer::Index.actual_nesting(@nesting, name).join("::")
+
+        attached_ancestors = begin
+          @index.linearized_ancestors_of(fully_qualified_name)
+        rescue RubyIndexer::Index::NonExistingNamespaceError
+          # When there are dynamic parts in the constant path, we will not have indexed the namespace. We can still
+          # provide test functionality if the class inherits directly from Test::Unit::TestCase or Minitest::Test
+          [node.superclass&.slice].compact
+        end
+
+        if attached_ancestors.include?("Test::Unit::TestCase") ||
+            non_declarative_minitest?(attached_ancestors, fully_qualified_name)
+
+          @response_builder.add(Requests::Support::TestItem.new(
+            fully_qualified_name,
+            fully_qualified_name,
+            @uri,
+            range_from_node(node),
+          ))
+        end
+
+        @nesting << name
+      end
+
+      sig { params(node: Prism::ModuleNode).void }
+      def on_module_node_enter(node)
+        @visibility_stack << :public
+
+        name = constant_name(node.constant_path)
+        name ||= name_with_dynamic_reference(node.constant_path)
+
+        @nesting << name
+      end
+
+      sig { params(node: Prism::ModuleNode).void }
+      def on_module_node_leave(node)
+        @visibility_stack.pop
+        @nesting.pop
+      end
+
+      sig { params(node: Prism::ClassNode).void }
+      def on_class_node_leave(node)
+        @visibility_stack.pop
+        @nesting.pop
+      end
+
+      sig { params(node: Prism::DefNode).void }
+      def on_def_node_enter(node)
+        return if @visibility_stack.last != :public
+
+        name = node.name.to_s
+        return unless name.start_with?("test_")
+
+        current_group_name = RubyIndexer::Index.actual_nesting(@nesting, nil).join("::")
+
+        # If we're finding a test method, but for the wrong framework, then the group test item will not have been
+        # previously pushed and thus we return early and avoid adding items for a framework this listener is not
+        # interested in
+        test_item = @response_builder[current_group_name]
+        return unless test_item
+
+        test_item.add(Requests::Support::TestItem.new(
+          "#{current_group_name}##{name}",
+          name,
+          @uri,
+          range_from_node(node),
+        ))
+      end
+
+      sig { params(node: Prism::CallNode).void }
+      def on_call_node_enter(node)
+        name = node.name
+        return unless ACCESS_MODIFIERS.include?(name)
+
+        @visibility_stack << name
+      end
+
+      sig { params(node: Prism::CallNode).void }
+      def on_call_node_leave(node)
+        name = node.name
+        return unless ACCESS_MODIFIERS.include?(name)
+        return unless node.arguments&.arguments
+
+        @visibility_stack.pop
+      end
+
+      private
+
+      sig { params(attached_ancestors: T::Array[String], fully_qualified_name: String).returns(T::Boolean) }
+      def non_declarative_minitest?(attached_ancestors, fully_qualified_name)
+        return false unless attached_ancestors.include?("Minitest::Test")
+
+        # We only support regular Minitest tests. The declarative syntax provided by ActiveSupport is handled by the
+        # Rails add-on
+        name_parts = fully_qualified_name.split("::")
+        singleton_name = "#{name_parts.join("::")}::<Class:#{name_parts.last}>"
+        !@index.linearized_ancestors_of(singleton_name).include?("ActiveSupport::Testing::Declarative")
+      rescue RubyIndexer::Index::NonExistingNamespaceError
+        true
+      end
+
+      sig do
+        params(
+          node: T.any(
+            Prism::ConstantPathNode,
+            Prism::ConstantReadNode,
+            Prism::ConstantPathTargetNode,
+            Prism::CallNode,
+            Prism::MissingNode,
+          ),
+        ).returns(String)
+      end
+      def name_with_dynamic_reference(node)
+        slice = node.slice
+        slice.gsub(/((?<=::)|^)[a-z]\w*/, DYNAMIC_REFERENCE_MARKER)
+      end
+    end
+  end
+end

lib/ruby_lsp/requests/discover_tests.rb

@@ -0,0 +1,62 @@
+# typed: strict
+# frozen_string_literal: true
+
+require "ruby_lsp/listeners/test_style"
+
+module RubyLsp
+  module Requests
+    # This is a custom request to ask the server to parse a test file and discover all available examples in it. Add-ons
+    # can augment the behavior through listeners, allowing them to handle discovery for different frameworks
+    class DiscoverTests < Request
+      extend T::Sig
+      include Support::Common
+
+      sig { params(global_state: GlobalState, document: RubyDocument, dispatcher: Prism::Dispatcher).void }
+      def initialize(global_state, document, dispatcher)
+        super()
+        @global_state = global_state
+        @document = document
+        @dispatcher = dispatcher
+        @response_builder = T.let(ResponseBuilders::TestCollection.new, ResponseBuilders::TestCollection)
+        @index = T.let(global_state.index, RubyIndexer::Index)
+      end
+
+      sig { override.returns(T::Array[Support::TestItem]) }
+      def perform
+        uri = @document.uri
+
+        # We normally only index test files once they are opened in the editor to save memory and avoid doing
+        # unnecessary work. If the file is already opened and we already indexed it, then we can just discover the tests
+        # straight away.
+        #
+        # However, if the user navigates to a specific test file from the explorer with nothing opened in the UI, then
+        # we will not have indexed the test file yet and trying to linearize the ancestor of the class will fail. In
+        # this case, we have to instantiate the indexer listener first, so that we insert classes, modules and methods
+        # in the index first and then discover the tests, all in the same traversal.
+        if @index.entries_for(uri.to_s)
+          Listeners::TestStyle.new(@response_builder, @global_state, @dispatcher, @document.uri)
+          @dispatcher.visit(@document.parse_result.value)
+        else
+          @global_state.synchronize do
+            RubyIndexer::DeclarationListener.new(
+              @index,
+              @dispatcher,
+              @document.parse_result,
+              uri,
+              collect_comments: true,
+            )
+
+            Listeners::TestStyle.new(@response_builder, @global_state, @dispatcher, @document.uri)
+
+            # Dispatch the events both for indexing the test file and discovering the tests. The order here is
+            # important because we need the index to be aware of the existing classes/modules/methods before the test
+            # listeners can do their work
+            @dispatcher.visit(@document.parse_result.value)
+          end
+        end
+
+        @response_builder.response
+      end
+    end
+  end
+end

lib/ruby_lsp/requests/support/common.rb

@@ -141,6 +141,8 @@ def markdown_from_index_entries(title, entries, max_entries = nil, extra_links:
               Prism::ConstantPathNode,
               Prism::ConstantReadNode,
               Prism::ConstantPathTargetNode,
+              Prism::CallNode,
+              Prism::MissingNode,
             ),
           ).returns(T.nilable(String))
         end

lib/ruby_lsp/server.rb

@@ -110,6 +110,8 @@ def process_message(message)
         compose_bundle(message)
       when "rubyLsp/diagnoseState"
         diagnose_state(message)
+      when "rubyLsp/discoverTests"
+        discover_tests(message)
       when "$/cancelRequest"
         @global_state.synchronize { @cancelled_requests << message[:params][:id] }
       when nil
@@ -1389,5 +1391,28 @@ def diagnose_state(message)
         ),
       )
     end
+
+    # Discovers all available test groups and examples in a given file taking into consideration the merged response of
+    # all add-ons
+    sig { params(message: T::Hash[Symbol, T.untyped]).void }
+    def discover_tests(message)
+      document = @store.get(message.dig(:params, :textDocument, :uri))
+
+      unless document.is_a?(RubyDocument)
+        send_empty_response(message[:id])
+        return
+      end
+
+      cached_response = document.cache_get("rubyLsp/discoverTests")
+      if cached_response != Document::EMPTY_CACHE
+        send_message(Result.new(id: message[:id], response: cached_response.map(&:to_hash)))
+        return
+      end
+
+      items = Requests::DiscoverTests.new(@global_state, document, Prism::Dispatcher.new).perform
+      document.cache_set("rubyLsp/discoverTests", items)
+
+      send_message(Result.new(id: message[:id], response: items.map(&:to_hash)))
+    end
   end
 end

project-words

@@ -103,6 +103,7 @@ unaliased
 unindexed
 unparser
 unresolve
+vcall
 Vinicius
 vscodemachineid
 vsctm