From c90c117174fabb35787a98200c03cfcebf0efb48 Mon Sep 17 00:00:00 2001
From: Rob Kiefer <rob.kiefer@gmail.com>
Date: Fri, 1 Mar 2019 00:10:04 -0500
Subject: [PATCH] Improve test coverage for generate queries

These functions are easy to cover with unit tests, so let's get them
in there.
---
 .../databases/timescaledb/devops.go           | 18 ++++---
 .../databases/timescaledb/devops_test.go      | 48 +++++++++++++++++++
 2 files changed, 59 insertions(+), 7 deletions(-)

diff --git a/cmd/tsbs_generate_queries/databases/timescaledb/devops.go b/cmd/tsbs_generate_queries/databases/timescaledb/devops.go
index 0b43cf459..57fe84594 100644
--- a/cmd/tsbs_generate_queries/databases/timescaledb/devops.go
+++ b/cmd/tsbs_generate_queries/databases/timescaledb/devops.go
@@ -9,8 +9,13 @@ import (
 	"github.com/timescale/tsbs/query"
 )
 
-const oneMinute = 60
-const oneHour = oneMinute * 60
+const (
+	oneMinute = 60
+	oneHour   = oneMinute * 60
+
+	timeBucketFmt    = "time_bucket('%d seconds', time)"
+	nonTimeBucketFmt = "to_timestamp(((extract(epoch from time)::int)/%d)*%d)"
+)
 
 // Devops produces TimescaleDB-specific queries for all the devops query types.
 type Devops struct {
@@ -55,17 +60,16 @@ func (d *Devops) getHostWhereWithHostnames(hostnames []string) string {
 }
 
 // getHostWhereString gets multiple random hostnames and creates a WHERE SQL statement for these hostnames.
-func (d *Devops) getHostWhereString(nhosts int) string {
-	hostnames := d.GetRandomHosts(nhosts)
+func (d *Devops) getHostWhereString(nHosts int) string {
+	hostnames := d.GetRandomHosts(nHosts)
 	return d.getHostWhereWithHostnames(hostnames)
 }
 
 func (d *Devops) getTimeBucket(seconds int) string {
 	if d.UseTimeBucket {
-		return fmt.Sprintf("time_bucket('%d seconds', time)", seconds)
+		return fmt.Sprintf(timeBucketFmt, seconds)
 	}
-
-	return fmt.Sprintf("to_timestamp(((extract(epoch from time)::int)/%d)*%d)", seconds, seconds)
+	return fmt.Sprintf(nonTimeBucketFmt, seconds, seconds)
 }
 
 func (d *Devops) getSelectClausesAggMetrics(agg string, metrics []string) []string {
diff --git a/cmd/tsbs_generate_queries/databases/timescaledb/devops_test.go b/cmd/tsbs_generate_queries/databases/timescaledb/devops_test.go
index bb27c2991..c435a3a30 100644
--- a/cmd/tsbs_generate_queries/databases/timescaledb/devops_test.go
+++ b/cmd/tsbs_generate_queries/databases/timescaledb/devops_test.go
@@ -1,6 +1,8 @@
 package timescaledb
 
 import (
+	"fmt"
+	"math/rand"
 	"strings"
 	"testing"
 	"time"
@@ -69,6 +71,52 @@ func TestDevopsGetHostWhereWithHostnames(t *testing.T) {
 	}
 }
 
+func TestDevopsGetHostWhereString(t *testing.T) {
+	cases := []struct {
+		nHosts int
+		want   string
+	}{
+		{
+			nHosts: 1,
+			want:   "(hostname = 'host_5')",
+		},
+		{
+			nHosts: 2,
+			want:   "(hostname = 'host_5' OR hostname = 'host_9')",
+		},
+		{
+			nHosts: 5,
+			want:   "(hostname = 'host_5' OR hostname = 'host_9' OR hostname = 'host_3' OR hostname = 'host_1' OR hostname = 'host_7')",
+		},
+	}
+
+	for _, c := range cases {
+		rand.Seed(123)
+		d := NewDevops(time.Now(), time.Now(), 10)
+
+		if got := d.getHostWhereString(c.nHosts); got != c.want {
+			t.Errorf("incorrect output for %d hosts: got %s want %s", c.nHosts, got, c.want)
+		}
+	}
+}
+
+func TestDevopsGetTimeBucket(t *testing.T) {
+	d := NewDevops(time.Now(), time.Now(), 10)
+	d.UseTimeBucket = false
+
+	seconds := 60
+	want := fmt.Sprintf(nonTimeBucketFmt, seconds, seconds)
+	if got := d.getTimeBucket(seconds); got != want {
+		t.Errorf("incorrect non time bucket format: got %s want %s", got, want)
+	}
+
+	d.UseTimeBucket = true
+	want = fmt.Sprintf(timeBucketFmt, seconds)
+	if got := d.getTimeBucket(seconds); got != want {
+		t.Errorf("incorrect time bucket format: got %s want %s", got, want)
+	}
+}
+
 func TestDevopsGetSelectClausesAggMetrics(t *testing.T) {
 	cases := []struct {
 		desc    string