Backup fix, tests.

tests/backup_test.go

@@ -124,4 +124,46 @@ func TestBackup(t *testing.T) {
 			t.Fatal(err)
 		}
 	}()
+
+	func() { // Incremental.
+		db, err := sqlite3.Open(backupName)
+		if err != nil {
+			t.Fatal(err)
+		}
+		defer db.Close()
+
+		b, err := db.BackupInit("main", ":memory:")
+		if err != nil {
+			t.Fatal(err)
+		}
+		defer b.Close()
+
+		done, err := b.Step(1)
+		if done {
+			t.Error("want false")
+		}
+		if err != nil {
+			t.Error(err)
+		}
+
+		n := b.Remaining()
+		if n != 1 {
+			t.Errorf("got %d", n)
+		}
+
+		n = b.PageCount()
+		if n != 2 {
+			t.Errorf("got %d", n)
+		}
+
+		err = b.Close()
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		err = db.Close()
+		if err != nil {
+			t.Fatal(err)
+		}
+	}()
 }

tests/driver_test.go

@@ -27,18 +27,32 @@ func TestDriver(t *testing.T) {
 	}
 	defer conn.Close()
 
-	_, err = conn.ExecContext(ctx,
+	res, err := conn.ExecContext(ctx,
 		`CREATE TABLE IF NOT EXISTS users (id INT, name VARCHAR(10))`)
 	if err != nil {
 		t.Fatal(err)
 	}
+	changes, err := res.RowsAffected()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if changes != 0 {
+		t.Errorf("got %d want 0", changes)
+	}
+	id, err := res.LastInsertId()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if id != 0 {
+		t.Errorf("got %d want 0", changes)
+	}
 
-	res, err := conn.ExecContext(ctx,
+	res, err = conn.ExecContext(ctx,
 		`INSERT INTO users (id, name) VALUES (0, 'go'), (1, 'zig'), (2, 'whatever')`)
 	if err != nil {
 		t.Fatal(err)
 	}
-	changes, err := res.RowsAffected()
+	changes, err = res.RowsAffected()
 	if err != nil {
 		t.Fatal(err)
 	}