1 files changed, 55 insertions, 0 deletions
diff --git a/spec/lib/banzai/filter/inline_metrics_filter_spec.rb b/spec/lib/banzai/filter/inline_metrics_filter_spec.rb
new file mode 100644
index 00000000000..772c94e3180
--- /dev/null
+++ b/spec/lib/banzai/filter/inline_metrics_filter_spec.rb
@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Banzai::Filter::InlineMetricsFilter do
+  include FilterSpecHelper
+
+  let(:input) { %(<a href="#{url}">example</a>) }
+  let(:doc) { filter(input) }
+
+  context 'when the document has an external link' do
+    let(:url) { 'https://foo.com' }
+
+    it 'leaves regular non-metrics links unchanged' do
+      expect(doc.to_s).to eq input
+    end
+  end
+
+  context 'when the document has a metrics dashboard link' do
+    let(:params) { ['foo', 'bar', 12] }
+    let(:url) { urls.metrics_namespace_project_environment_url(*params) }
+
+    it 'leaves the original link unchanged' do
+      expect(doc.at_css('a').to_s).to eq input
+    end
+
+    it 'appends a metrics charts placeholder with dashboard url after metrics links' do
+      node = doc.at_css('.js-render-metrics')
+      expect(node).to be_present
+
+      dashboard_url = urls.metrics_dashboard_namespace_project_environment_url(*params, embedded: true)
+      expect(node.attribute('data-dashboard-url').to_s).to eq dashboard_url
+    end
+
+    context 'when the metrics dashboard link is part of a paragraph' do
+      let(:paragraph) { %(This is an <a href="#{url}">example</a> of metrics.) }
+      let(:input) { %(<p>#{paragraph}</p>) }
+
+      it 'appends the charts placeholder after the enclosing paragraph' do
+        expect(doc.at_css('p').to_s).to include paragraph
+        expect(doc.at_css('.js-render-metrics')).to be_present
+      end
+
+      context 'when the feature is disabled' do
+        before do
+          stub_feature_flags(gfm_embedded_metrics: false)
+        end
+
+        it 'does nothing' do
+          expect(doc.to_s).to eq input
+        end
+      end
+    end
+  end
+end