1 files changed, 44 insertions, 0 deletions
diff --git a/spec/lib/gitlab/graphql/tracers/timer_tracer_spec.rb b/spec/lib/gitlab/graphql/tracers/timer_tracer_spec.rb
new file mode 100644
index 00000000000..7f837e28772
--- /dev/null
+++ b/spec/lib/gitlab/graphql/tracers/timer_tracer_spec.rb
@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+require "fast_spec_helper"
+require "support/graphql/fake_tracer"
+require "support/graphql/fake_query_type"
+
+RSpec.describe Gitlab::Graphql::Tracers::TimerTracer do
+  let(:expected_duration) { 5 }
+  let(:tracer_spy) { spy('tracer_spy') }
+  let(:dummy_schema) do
+    schema = Class.new(GraphQL::Schema) do
+      use Gitlab::Graphql::Tracers::TimerTracer
+
+      query Graphql::FakeQueryType
+    end
+
+    schema.tracer(Graphql::FakeTracer.new(lambda { |*args| tracer_spy.trace(*args) }))
+
+    schema
+  end
+
+  before do
+    current_time = 0
+    allow(Gitlab::Metrics::System).to receive(:monotonic_time) do
+      current_time += expected_duration
+    end
+  end
+
+  it "adds duration_s to the trace metadata", :aggregate_failures do
+    query_string = "query fooOperation { helloWorld }"
+
+    dummy_schema.execute(query_string)
+
+    # "parse" and "execute_query" are just arbitrary trace events
+    expect(tracer_spy).to have_received(:trace).with("parse", {
+      duration_s: expected_duration,
+      query_string: query_string
+    })
+    expect(tracer_spy).to have_received(:trace).with("execute_query", {
+      # greater than expected duration because other calls made to `.monotonic_time` are outside our control
+      duration_s: be >= expected_duration,
+      query: instance_of(GraphQL::Query)
+    })
+  end
+end