From 430becdd3f21c308201cd17fb7fb1426b8bafc2a Mon Sep 17 00:00:00 2001
From: Cody Soyland <cody@soyland.org>
Date: Fri, 7 Jun 2019 09:58:40 -0500
Subject: [PATCH] Add tests for prometheus stats client

---
 go.mod                        |  1 +
 prometheus/prometheus_test.go | 82 +++++++++++++++++++++++++++++++++++
 2 files changed, 83 insertions(+)
 create mode 100644 prometheus/prometheus_test.go

diff --git a/go.mod b/go.mod
index 9f822ee6b..883b3ca9e 100644
--- a/go.mod
+++ b/go.mod
@@ -23,6 +23,7 @@ require (
 	github.com/pelletier/go-toml v1.2.0
 	github.com/pkg/errors v0.8.1
 	github.com/prometheus/client_golang v0.9.3
+	github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90
 	github.com/remyoudompheng/bigfft v0.0.0-20190321074620-2f0d2b0e0001 // indirect
 	github.com/satori/go.uuid v1.2.0
 	github.com/shirou/gopsutil v2.18.12+incompatible
diff --git a/prometheus/prometheus_test.go b/prometheus/prometheus_test.go
new file mode 100644
index 000000000..d40a0ecd8
--- /dev/null
+++ b/prometheus/prometheus_test.go
@@ -0,0 +1,82 @@
+// Copyright 2017 Pilosa Corp.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus_test
+
+import (
+	"reflect"
+	"testing"
+	"time"
+
+	pilosaPrometheus "github.com/pilosa/pilosa/prometheus"
+	"github.com/prometheus/client_golang/prometheus"
+	io_prometheus_client "github.com/prometheus/client_model/go"
+)
+
+func TestPrometheusClient_WithTags(t *testing.T) {
+	// Create a new client.
+	c, err := pilosaPrometheus.NewPrometheusClient()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer c.Close()
+
+	// Create a new client with additional tags.
+	c1 := c.WithTags("foo", "bar")
+	if tags := c1.Tags(); !reflect.DeepEqual(tags, []string{"bar", "foo"}) {
+		t.Fatalf("unexpected tags: %+v", tags)
+	}
+
+	// Create a new client from the clone with more tags.
+	c2 := c1.WithTags("bar", "baz")
+	if tags := c2.Tags(); !reflect.DeepEqual(tags, []string{"bar", "baz", "foo"}) {
+		t.Fatalf("unexpected tags: %+v", tags)
+	}
+}
+
+func TestPrometheusClient_Methods(t *testing.T) {
+	// Create a new client.
+	c, err := pilosaPrometheus.NewPrometheusClient()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer c.Close()
+
+	dur, _ := time.ParseDuration("123us")
+	c.CountWithCustomTags("ct", 1, 1.0, []string{"foo:bar"})
+	c.Count("cc", 1, 1.0)
+	c.Gauge("gg", 10, 1.0)
+	c.Histogram("hh", 1, 1.0)
+	c.Timing("tt", dur, 1.0)
+
+	metricFams, err := prometheus.DefaultGatherer.Gather()
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, metricName := range []string{"pilosa_ct", "pilosa_cc", "pilosa_gg", "pilosa_hh", "pilosa_tt"} {
+		if metricExists(metricName, metricFams) {
+			continue
+		}
+		t.Fatalf("Metric was not recorded: %s", metricName)
+	}
+}
+
+func metricExists(metricName string, metricFams []*io_prometheus_client.MetricFamily) bool {
+	for _, metricFam := range metricFams {
+		if metricFam.GetName() == metricName {
+			return true
+		}
+	}
+	return false
+}