storage: postgres per-test isolation

src/storage/tests/storage_test.go

@@ -1,16 +1,32 @@
 package tests
 
 import (
+	"crypto/rand"
+	"database/sql"
+	"encoding/hex"
+	"fmt"
+	"net/url"
+	"os"
 	"testing"
 
+	_ "github.com/lib/pq"
 	"github.com/nkanaev/yarr/src/storage"
 )
 
 func dbtest(t *testing.T, testcase func(t *testing.T, db storage.Storage)) {
 	testurls := map[string]string{
 		"sqlite": ":memory:",
-		// "postgres": "postgres://postgres:postgres@localhost:5432/yarr_test?sslmode=disable",
 	}
+
+	if pgUrl := os.Getenv("YARR_POSTGRES_TEST_URL"); pgUrl != "" {
+		dburl, cleanup, err := createPostgresDB(pgUrl)
+		if err != nil {
+			t.Fatalf("failed to create postgres test database: %v", err)
+		}
+		t.Cleanup(cleanup)
+		testurls["postgres"] = dburl
+	}
+
 	for testname, url := range testurls {
 		db, err := storage.New(url)
 		if err != nil {
@@ -21,3 +37,50 @@ func dbtest(t *testing.T, testcase func(t *testing.T, db storage.Storage)) {
 		})
 	}
 }
+
+func createPostgresDB(pgUrl string) (string, func(), error) {
+	u, err := url.Parse(pgUrl)
+	if err != nil {
+		return "", nil, err
+	}
+
+	u.Path = "/postgres"
+	adminConnStr := u.String()
+
+	adminDB, err := sql.Open("postgres", adminConnStr)
+	if err != nil {
+		return "", nil, fmt.Errorf("admin connect: %w", err)
+	}
+
+	b := make([]byte, 4)
+	if _, err := rand.Read(b); err != nil {
+		adminDB.Close()
+		return "", nil, fmt.Errorf("generate suffix: %w", err)
+	}
+
+	testDBName := "yarr_test_" + hex.EncodeToString(b)
+
+	if _, err := adminDB.Exec(fmt.Sprintf(`CREATE DATABASE "%s"`, testDBName)); err != nil {
+		adminDB.Close()
+		return "", nil, fmt.Errorf("create database: %w", err)
+	}
+	adminDB.Close()
+
+	u.Path = "/" + testDBName
+	testURL := u.String()
+
+	cleanup := func() {
+		dropDB, err := sql.Open("postgres", adminConnStr)
+		if err != nil {
+			return
+		}
+		defer dropDB.Close()
+		dropDB.Exec(fmt.Sprintf(
+			`SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE datname = '%s' AND pid <> pg_backend_pid()`,
+			testDBName,
+		))
+		dropDB.Exec(fmt.Sprintf(`DROP DATABASE IF EXISTS "%s"`, testDBName))
+	}
+
+	return testURL, cleanup, nil
+}