Extract artifact existence check into method

app/controllers/projects/artifacts_controller.rb

@@ -108,9 +108,7 @@ class Projects::ArtifactsController < Projects::ApplicationController
   end
 
   def validate_artifacts!
-    if build.nil? || build.artifacts_file.nil? || (build.pipeline.unlocked? && build.artifacts_expired?)
-      render_404
-    end
+    render_404 unless build&.available_artifacts?
   end
 
   def build

app/models/ci/build.rb

@@ -647,6 +647,13 @@ module Ci
       !artifacts_expired? && artifacts_file&.exists?
     end
 
+    # This method is similar to #artifacts? but it includes the artifacts
+    # locking mechanics. A new method was created to prevent breaking existing
+    # behavior and avoid introducing N+1s.
+    def available_artifacts?
+      (!artifacts_expired? || pipeline.artifacts_locked?) && job_artifacts_archive&.exists?
+    end
+
     def artifacts_metadata?
       artifacts? && artifacts_metadata&.exists?
     end

spec/models/ci/build_spec.rb

@@ -612,6 +612,62 @@ RSpec.describe Ci::Build do
     end
   end
 
+  describe '#available_artifacts?' do
+    let(:build) { create(:ci_build) }
+
+    subject { build.available_artifacts? }
+
+    context 'when artifacts are not expired' do
+      before do
+        build.artifacts_expire_at = Date.tomorrow
+      end
+
+      context 'when artifacts exist' do
+        before do
+          create(:ci_job_artifact, :archive, job: build)
+        end
+
+        it { is_expected.to be_truthy }
+      end
+
+      context 'when artifacts do not exist' do
+        it { is_expected.to be_falsey }
+      end
+    end
+
+    context 'when artifacts are expired' do
+      before do
+        build.artifacts_expire_at = Date.yesterday
+      end
+
+      context 'when artifacts are not locked' do
+        before do
+          build.pipeline.locked = :unlocked
+        end
+
+        it { is_expected.to be_falsey }
+      end
+
+      context 'when artifacts are locked' do
+        before do
+          build.pipeline.locked = :artifacts_locked
+        end
+
+        context 'when artifacts exist' do
+          before do
+            create(:ci_job_artifact, :archive, job: build)
+          end
+
+          it { is_expected.to be_truthy }
+        end
+
+        context 'when artifacts do not exist' do
+          it { is_expected.to be_falsey }
+        end
+      end
+    end
+  end
+
   describe '#browsable_artifacts?' do
     subject { build.browsable_artifacts? }