Add replication slot test

Signed-off-by: Felix Yuan <[email protected]>

Author: Sticksman

Diff for: collector/replication_slots.go

@@ -47,19 +47,22 @@ var pgReplicationSlotConfirmedFlushLSN = prometheus.NewDesc(
 
 var pgReplicationSlotActive = prometheus.NewDesc(
 	"pg_replication_slot_is_active",
-	"last lsn confirmed flushed to the replication slot",
+	"whether the replication slot is active or not",
 	[]string{"slot_name"}, nil,
 )
 
+var pgReplicationSlotQuery = `SELECT
+	slot_name,
+	pg_current_wal_lsn() - '0/0' AS current_wal_lsn,
+	coalesce(confirmed_flush_lsn, '0/0') - '0/0',
+	active
+FROM
+	pg_replication_slots;
+`
+
 func (PGReplicationSlotCollector) Update(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	rows, err := db.QueryContext(ctx,
-		`SELECT
-			slot_name,
-			pg_current_wal_lsn() - '0/0' AS current_wal_lsn,
-			coalesce(confirmed_flush_lsn, '0/0') - '0/0',
-			active
-		FROM
-			pg_replication_slots;`)
+		pgReplicationSlotQuery)
 	if err != nil {
 		return err
 	}
@@ -70,10 +73,18 @@ func (PGReplicationSlotCollector) Update(ctx context.Context, db *sql.DB, ch cha
 		var wal_lsn int64
 		var flush_lsn int64
 		var is_active bool
+		var is_active_value int
+
 		if err := rows.Scan(&slot_name, &wal_lsn, &flush_lsn, &is_active); err != nil {
 			return err
 		}
 
+		if is_active {
+			is_active_value = 1
+		} else {
+			is_active_value = 0
+		}
+
 		ch <- prometheus.MustNewConstMetric(
 			pgReplicationSlotCurrentWalLSN,
 			prometheus.GaugeValue, float64(wal_lsn), slot_name,
@@ -86,7 +97,7 @@ func (PGReplicationSlotCollector) Update(ctx context.Context, db *sql.DB, ch cha
 		}
 		ch <- prometheus.MustNewConstMetric(
 			pgReplicationSlotActive,
-			prometheus.GaugeValue, float64(flush_lsn), slot_name,
+			prometheus.GaugeValue, float64(is_active_value), slot_name,
 		)
 	}
 	if err := rows.Err(); err != nil {

Diff for: collector/replication_slots_test.go

@@ -0,0 +1,89 @@
+package collector
+
+import (
+	"context"
+	"testing"
+
+	"github.com/DATA-DOG/go-sqlmock"
+	"github.com/prometheus/client_golang/prometheus"
+	dto "github.com/prometheus/client_model/go"
+	"github.com/smartystreets/goconvey/convey"
+)
+
+func TestPgReplicationSlotCollectorActive(t *testing.T) {
+	db, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("Error opening a stub db connection: %s", err)
+	}
+	defer db.Close()
+
+	columns := []string{"slot_name", "current_wal_lsn", "confirmed_flush_lsn", "active"}
+	rows := sqlmock.NewRows(columns).
+		AddRow("test_slot", 5, 3, true)
+	mock.ExpectQuery(sanitizeQuery(pgReplicationSlotQuery)).WillReturnRows(rows)
+
+	ch := make(chan prometheus.Metric)
+	go func() {
+		defer close(ch)
+		c := PGReplicationSlotCollector{}
+
+		if err := c.Update(context.Background(), db, ch); err != nil {
+			t.Errorf("Error calling PGPostmasterCollector.Update: %s", err)
+		}
+	}()
+
+	expected := []MetricResult{
+		{labels: labelMap{"slot_name": "test_slot"}, value: 5, metricType: dto.MetricType_GAUGE},
+		{labels: labelMap{"slot_name": "test_slot"}, value: 3, metricType: dto.MetricType_GAUGE},
+		{labels: labelMap{"slot_name": "test_slot"}, value: 1, metricType: dto.MetricType_GAUGE},
+	}
+
+	convey.Convey("Metrics comparison", t, func() {
+		for _, expect := range expected {
+			m := readMetric(<-ch)
+			convey.So(expect, convey.ShouldResemble, m)
+		}
+	})
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("there were unfulfilled exceptions: %s", err)
+	}
+}
+
+func TestPgReplicationSlotCollectorInActive(t *testing.T) {
+	db, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("Error opening a stub db connection: %s", err)
+	}
+	defer db.Close()
+
+	columns := []string{"slot_name", "current_wal_lsn", "confirmed_flush_lsn", "active"}
+	rows := sqlmock.NewRows(columns).
+		AddRow("test_slot", 6, 12, false)
+	mock.ExpectQuery(sanitizeQuery(pgReplicationSlotQuery)).WillReturnRows(rows)
+
+	ch := make(chan prometheus.Metric)
+	go func() {
+		defer close(ch)
+		c := PGReplicationSlotCollector{}
+
+		if err := c.Update(context.Background(), db, ch); err != nil {
+			t.Errorf("Error calling PGPostmasterCollector.Update: %s", err)
+		}
+	}()
+
+	expected := []MetricResult{
+		{labels: labelMap{"slot_name": "test_slot"}, value: 6, metricType: dto.MetricType_GAUGE},
+		{labels: labelMap{"slot_name": "test_slot"}, value: 0, metricType: dto.MetricType_GAUGE},
+	}
+
+	convey.Convey("Metrics comparison", t, func() {
+		for _, expect := range expected {
+			m := readMetric(<-ch)
+			convey.So(expect, convey.ShouldResemble, m)
+		}
+	})
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("there were unfulfilled exceptions: %s", err)
+	}
+
+}