pkg/sqlutil/sqltest: add CreateOrReplace (#1018)

pkg/sqlutil/sqltest/sqltest.go

@@ -1,7 +1,12 @@
 package sqltest
 
 import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"net/url"
 	"os"
+	"strings"
 	"testing"
 
 	"github.com/google/uuid"
@@ -47,3 +52,64 @@ func SkipInMemory(t *testing.T) {
 		t.Skip("skipping test due to in-memory db")
 	}
 }
+
+// CreateOrReplace creates a new database with the given name (optionally from template), and schedules it to be dropped
+// after test completion.
+func CreateOrReplace(t testing.TB, u url.URL, dbName string, template string) url.URL {
+	if u.Path == "" {
+		t.Fatal("path missing from database URL")
+	}
+
+	if l := len(dbName); l > 63 {
+		t.Fatalf("dbName %v too long (%d), max is 63 bytes", dbName, l)
+	}
+	// Cannot drop test database if we are connected to it, so we must connect
+	// to a different one. 'postgres' should be present on all postgres installations
+	u.Path = "/postgres"
+	db, err := sql.Open(pg.DriverPostgres, u.String())
+	if err != nil {
+		t.Fatalf("in order to drop the test database, we need to connect to a separate database"+
+			" called 'postgres'. But we are unable to open 'postgres' database: %+v\n", err)
+	}
+	defer db.Close()
+
+	_, err = db.Exec(fmt.Sprintf("DROP DATABASE IF EXISTS %s", dbName))
+	if err != nil {
+		t.Fatalf("unable to drop postgres migrations test database: %v", err)
+	}
+	if template != "" {
+		_, err = db.Exec(fmt.Sprintf("CREATE DATABASE %s WITH TEMPLATE %s", dbName, template))
+	} else {
+		_, err = db.Exec(fmt.Sprintf("CREATE DATABASE %s", dbName))
+	}
+	if err != nil {
+		t.Fatalf("unable to create postgres test database with name '%s': %v", dbName, err)
+	}
+	u.Path = fmt.Sprintf("/%s", dbName)
+	t.Cleanup(func() { assert.NoError(t, drop(u)) })
+	return u
+}
+
+// drop drops the database at the given URL.
+func drop(dbURL url.URL) error {
+	if dbURL.Path == "" {
+		return errors.New("path missing from database URL")
+	}
+	dbname := strings.TrimPrefix(dbURL.Path, "/")
+
+	// Cannot drop test database if we are connected to it, so we must connect
+	// to a different one. 'postgres' should be present on all postgres installations
+	dbURL.Path = "/postgres"
+	db, err := sql.Open(pg.DriverPostgres, dbURL.String())
+	if err != nil {
+		return fmt.Errorf("in order to drop the test database, we need to connect to a separate database"+
+			" called 'postgres'. But we are unable to open 'postgres' database: %+v\n", err)
+	}
+	defer db.Close()
+
+	_, err = db.Exec(fmt.Sprintf("DROP DATABASE IF EXISTS %s", dbname))
+	if err != nil {
+		return fmt.Errorf("unable to drop postgres migrations test database: %v", err)
+	}
+	return nil
+}