fix(yabeda): Normalize plural Yabeda units to Sentry's singular form

Yabeda plugins declare units as plural Ruby symbols (:seconds,
:milliseconds, :bytes) while Sentry's canonical unit format is
singular (second, millisecond, byte). Without normalization,
distribution metrics with units are stored under the wrong unit
string, causing dashboard queries to return empty results.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: dingsdax

sentry-yabeda/lib/sentry/yabeda/adapter.rb

@@ -68,11 +68,8 @@ def metric_name(metric)
         [metric.group, metric.name].compact.join(".")
       end
 
-      # TODO: Normalize Yabeda unit symbols (e.g. :milliseconds) to Sentry's
-      # canonical singular strings (e.g. "millisecond") once units are visible
-      # in the Sentry product. See https://develop.sentry.dev/sdk/foundations/state-management/scopes/attributes/#units
       def unit_for(metric)
-        metric.unit&.to_s
+        metric.unit&.to_s&.chomp("s")
       end
     end
   end

sentry-yabeda/spec/sentry/yabeda/adapter_spec.rb

@@ -85,7 +85,7 @@ def build_metric(type, name:, group: nil, unit: nil)
       expect(Sentry.metrics).to receive(:gauge).with(
         "process.memory_usage",
         1024,
-        unit: "bytes",
+        unit: "byte",
         attributes: nil
       )
 
@@ -101,7 +101,7 @@ def build_metric(type, name:, group: nil, unit: nil)
       expect(Sentry.metrics).to receive(:distribution).with(
         "rails.request_duration",
         150.5,
-        unit: "milliseconds",
+        unit: "millisecond",
         attributes: tags
       )
 
@@ -117,14 +117,60 @@ def build_metric(type, name:, group: nil, unit: nil)
       expect(Sentry.metrics).to receive(:distribution).with(
         "http.response_size",
         2048,
-        unit: "bytes",
+        unit: "byte",
         attributes: tags
       )
 
       adapter.perform_summary_observe!(summary, tags, 2048)
     end
   end
 
+  describe "unit normalization" do
+    it "converts plural yabeda units to Sentry's singular form" do
+      perform_basic_setup
+
+      histogram = build_metric(:histogram, name: :duration, group: :rails, unit: :seconds)
+      expect(Sentry.metrics).to receive(:distribution).with(
+        "rails.duration", 1.5, unit: "second", attributes: nil
+      )
+
+      adapter.perform_histogram_measure!(histogram, {}, 1.5)
+    end
+
+    it "converts milliseconds to millisecond" do
+      perform_basic_setup
+
+      histogram = build_metric(:histogram, name: :latency, unit: :milliseconds)
+      expect(Sentry.metrics).to receive(:distribution).with(
+        "latency", 250.0, unit: "millisecond", attributes: nil
+      )
+
+      adapter.perform_histogram_measure!(histogram, {}, 250.0)
+    end
+
+    it "passes nil when unit is not set" do
+      perform_basic_setup
+
+      gauge = build_metric(:gauge, name: :threads)
+      expect(Sentry.metrics).to receive(:gauge).with(
+        "threads", 5, unit: nil, attributes: nil
+      )
+
+      adapter.perform_gauge_set!(gauge, {}, 5)
+    end
+
+    it "leaves already-singular units unchanged" do
+      perform_basic_setup
+
+      gauge = build_metric(:gauge, name: :uptime, unit: :second)
+      expect(Sentry.metrics).to receive(:gauge).with(
+        "uptime", 3600, unit: "second", attributes: nil
+      )
+
+      adapter.perform_gauge_set!(gauge, {}, 3600)
+    end
+  end
+
   describe "registration methods (no-ops)" do
     it "accepts register_counter! without error" do
       expect { adapter.register_counter!(double) }.not_to raise_error

sentry-yabeda/spec/sentry/yabeda/integration_spec.rb

@@ -78,7 +78,7 @@
     expect(metric[:name]).to eq("myapp.response_time")
     expect(metric[:type]).to eq(:distribution)
     expect(metric[:value]).to eq(150.5)
-    expect(metric[:unit]).to eq("milliseconds")
+    expect(metric[:unit]).to eq("millisecond")
     expect(metric[:attributes][:controller]).to eq({ type: "string", value: "orders" })
     expect(metric[:attributes][:action]).to eq({ type: "string", value: "index" })
   end