Create DB management / versioning package

pkg/db/connect_test.go

@@ -0,0 +1,85 @@
+package db_test
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/jmoiron/sqlx"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"gas_stack/pkg/db"
+)
+
+func TestCreateAndConnectToDB(t *testing.T) {
+	assert := assert.New(t)
+
+	_schema_sql, err := os.ReadFile("../../sample_data/test_schemas/food.sql")
+	require.NoError(t, err)
+	schema_sql := string(_schema_sql)
+	migrations := []string{}
+
+	db.Init(&schema_sql, &migrations)
+
+	data_dir := "../../sample_data/data"
+	// Create then connect to a new empty DB
+	dbPath := filepath.Join(data_dir, "test.db")
+	_ = os.Remove(dbPath) // Delete it if it exists
+
+	_, err = db.Create(dbPath)
+	assert.NoError(err)
+	_, err = db.Connect(dbPath)
+	assert.NoError(err)
+}
+
+func TestVersionUpgrade(t *testing.T) {
+	require := require.New(t)
+
+	// Create a little schema
+	initial_schema := `
+		create table items(rowid integer primary key);
+		create table db_version (version integer primary key) strict, without rowid;
+		insert into db_version values(0);
+	`
+	migrations := []string{}
+	db.Init(&initial_schema, &migrations)
+
+	connection, err := db.Create(":memory:")
+	require.NoError(err)
+
+	get_version := func(c *sqlx.DB) (ret int) {
+		// TODO: this should be a function exposed by the `db` package itself
+		c.Get(&ret, "select version from db_version")
+		return
+	}
+
+	var items []int
+	connection.Select(&items, "select * from items")
+	require.Len(items, 0)
+	require.Equal(0, get_version(connection))
+
+	// Create a migration to add a new Item
+	migrations = append(migrations, "insert into items (rowid) values (1)")
+	db.Init(&initial_schema, &migrations) // Reinitialize with the new migration
+	db.UpgradeFromXToY(connection, uint(len(migrations)-1), uint(len(migrations)))
+
+	var items2 []int
+	connection.Select(&items2, "select * from items")
+	require.Len(items2, 1)
+	require.Equal(1, get_version(connection))
+
+	// Create a migration to add a new Item
+	migrations = append(migrations, `alter table items add column name string default 'asdf'`)
+	db.Init(&initial_schema, &migrations) // Reinitialize with the new migration
+	db.UpgradeFromXToY(connection, uint(len(migrations)-1), uint(len(migrations)))
+
+	var items3 []struct {
+		ID   uint64 `db:"rowid"`
+		Name string `db:"name"`
+	}
+	connection.Select(&items3, "select * from items")
+	require.Len(items2, 1)
+	assert.Equal(t, "asdf", items3[0].Name)
+	require.Equal(2, get_version(connection))
+}