Add tests for the rename column operation

pkg/migrations/op_rename_column_test.go

@@ -0,0 +1,81 @@
+package migrations_test
+
+import (
+	"database/sql"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"pg-roll/pkg/migrations"
+)
+
+func TestRenameColumn(t *testing.T) {
+	t.Parallel()
+
+	ExecuteTests(t, TestCases{{
+		name: "rename column",
+		migrations: []migrations.Migration{
+			{
+				Name: "01_add_table",
+				Operations: migrations.Operations{
+					&migrations.OpCreateTable{
+						Name: "users",
+						Columns: []migrations.Column{
+							{
+								Name:       "id",
+								Type:       "serial",
+								PrimaryKey: true,
+							},
+							{
+								Name:     "username",
+								Type:     "varchar(255)",
+								Nullable: false,
+							},
+						},
+					},
+				},
+			},
+			{
+				Name: "02_rename_column",
+				Operations: migrations.Operations{
+					&migrations.OpRenameColumn{
+						Table: "users",
+						From:  "username",
+						To:    "name",
+					},
+				},
+			},
+		},
+		afterStart: func(t *testing.T, db *sql.DB) {
+			// The column in the underlying table has not been renamed.
+			ColumnMustExist(t, db, "public", "users", "username")
+
+			// Insertions to the new column name in the new version schema should work.
+			MustInsert(t, db, "public", "02_rename_column", "users", map[string]string{"name": "alice"})
+
+			// Insertions to the old column name in the old version schema should work.
+			MustInsert(t, db, "public", "01_add_table", "users", map[string]string{"username": "bob"})
+
+			// Data can be read from the view in the new version schema.
+			rows := MustSelect(t, db, "public", "02_rename_column", "users")
+			assert.Equal(t, []map[string]any{
+				{"id": 1, "name": "alice"},
+				{"id": 2, "name": "bob"},
+			}, rows)
+		},
+		afterRollback: func(t *testing.T, db *sql.DB) {
+			// no-op
+		},
+		afterComplete: func(t *testing.T, db *sql.DB) {
+			// The column in the underlying table has been renamed.
+			ColumnMustExist(t, db, "public", "users", "name")
+
+			// Data can be read from the view in the new version schema.
+			rows := MustSelect(t, db, "public", "02_rename_column", "users")
+			assert.Equal(t, []map[string]any{
+				{"id": 1, "name": "alice"},
+				{"id": 2, "name": "bob"},
+			}, rows)
+		},
+	}})
+}