fix: support empty nodes

.github/workflows/ruby.yml

@@ -12,12 +12,12 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [ '2.6', '2.7', '3.0' ]
+        ruby: [ '2.7', '3.0', '3.1', '3.2' ]
     env:
       RUBY_IMAGE: ${{ matrix.ruby }}
     name: Ruby ${{ matrix.ruby }}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:

.gitignore

@@ -6,6 +6,7 @@
 /gemfiles/
 /pkg/
 /spec/reports/
+/spec/internal/tmp/
 /tmp/
 .pry_history
 .rspec_status

.standard.yml

@@ -1 +1 @@
-ruby_version: 2.6
+ruby_version: 2.7

docker-compose.yml

@@ -1,6 +1,6 @@
 services:
   ruby:
-    image: ruby:${RUBY_IMAGE:-3.0}-buster
+    image: ruby:${RUBY_IMAGE:-2.7}-bullseye
     environment:
       HISTFILE: /app/.bash_history
       BUNDLE_PATH: /bundle

graphql-connections.gemspec

@@ -28,7 +28,7 @@ Gem::Specification.new do |spec|
   spec.bindir = "exe"
   spec.executables = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
-  spec.required_ruby_version = "> 2.5"
+  spec.required_ruby_version = "> 2.6"
 
   spec.add_runtime_dependency "activerecord", ">= 5"
   spec.add_runtime_dependency "graphql", [">= 1.10", "< 3.0"]
@@ -41,8 +41,8 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "pg", "~> 1.2"
   spec.add_development_dependency "pry-byebug", "~> 3"
   spec.add_development_dependency "rake", "~> 13.0"
-  spec.add_development_dependency "rspec-rails", "~> 5.0"
+  spec.add_development_dependency "rspec-rails", "~> 6.0"
   spec.add_development_dependency "standard", "~> 1.1"
-  spec.add_development_dependency "test-prof", "~> 1.0"
+  spec.add_development_dependency "test-prof", "~> 1.0.0"
 end
 # rubocop:enable Metrics/BlockLength

lefthook-local.dip_example.yml

@@ -1,4 +1,4 @@
 pre-commit:
   commands:
     rubocop:
-      runner: dip {cmd}
+      run: dip {cmd}

lefthook.yml

@@ -3,4 +3,4 @@ pre-commit:
     rubocop:
       tags: backend
       glob: "**/*.rb"
-      runner: bundle exec standardrb --fix {staged_files} && git add {staged_files}
+      run: bundle exec standardrb --fix {staged_files} && git add {staged_files}

lib/graphql/connections/keyset/asc.rb

@@ -42,10 +42,10 @@ def has_next_page
             false
           end
         end
-        # rubocop:enable Naming/PredicateName, Metrics/AbcSize, Metrics/MethodLength
 
         private
 
+        # standard:disable Metrics/AbcSize, Metrics/MethodLength
         def limited_relation
           scope = sliced_relation
           nodes = []
@@ -78,6 +78,7 @@ def sliced_relation_before(relation)
             .where(arel_table[primary_key].lt(before_cursor_primary_key))
             .or(relation.where(arel_table[field_key].lt(before_cursor_date)))
         end
+        # standard:enable Metrics/AbcSize, Metrics/MethodLength
       end
     end
   end

lib/graphql/connections/keyset/desc.rb

@@ -42,8 +42,8 @@ def has_next_page
             false
           end
         end
-        # rubocop:enable Naming/PredicateName, Metrics/AbcSize, Metrics/MethodLength
 
+        # standard:disable Metrics/AbcSize, Metrics/MethodLength
         def cursor_for(item)
           cursor = [item[field_key], item[primary_key]].map { |value| serialize(value) }.join(@separator)
           cursor = encode(cursor) if opaque_cursor
@@ -85,6 +85,7 @@ def sliced_relation_before(relation)
             .where(arel_table[primary_key].gt(before_cursor_primary_key))
             .or(relation.where(arel_table[field_key].gt(before_cursor_date)))
         end
+        # standard:disable Metrics/AbcSize, Metrics/MethodLength
       end
     end
   end

lib/graphql/connections/primary_key/base.rb

@@ -16,8 +16,10 @@ def initialize(*args, primary_key: nil, **kwargs)
         end
 
         def has_previous_page
+          return false if nodes.empty?
+
           if last
-            nodes.any? && items_exist?(type: :query, search: nodes.first[primary_key], page_type: :previous)
+            items_exist?(type: :query, search: nodes.first[primary_key], page_type: :previous)
           elsif after
             items_exist?(type: :cursor, search: after_cursor, page_type: :previous)
           else
@@ -26,6 +28,8 @@ def has_previous_page
         end
 
         def has_next_page
+          return false if nodes.empty?
+
           if first
             items_exist?(type: :query, search: nodes.last[primary_key], page_type: :next)
           elsif before

spec/lib/keyset/desc_spec.rb

@@ -26,6 +26,16 @@
       expect(connection.has_previous_page).to be false
       expect(connection.has_next_page).to be true
     end
+
+    context "with empty relation" do
+      let(:relation) { Message.none }
+
+      it "returns no nodes and has_previous_page and has_next_page are false" do
+        expect(nodes.size).to eq 0
+        expect(connection.has_previous_page).to be false
+        expect(connection.has_next_page).to be false
+      end
+    end
   end
 
   describe ":first param" do

spec/lib/primary_key/asc_spec.rb

@@ -26,6 +26,16 @@
       expect(connection.has_previous_page).to be false
       expect(connection.has_next_page).to be true
     end
+
+    context "with empty relation" do
+      let(:relation) { Message.none }
+
+      it "returns no nodes and has_previous_page and has_next_page are false" do
+        expect(nodes.size).to eq 0
+        expect(connection.has_previous_page).to be false
+        expect(connection.has_next_page).to be false
+      end
+    end
   end
 
   describe ":first param" do