fix(review): harden payment, oauth, and migration paths

backend/migrations/auth_identity_payment_migrations_regression_test.go

@@ -0,0 +1,37 @@
+package migrations
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestMigration112UsesIdempotentAddColumn(t *testing.T) {
+	content, err := FS.ReadFile("112_add_payment_order_provider_key_snapshot.sql")
+	require.NoError(t, err)
+
+	sql := string(content)
+	require.Contains(t, sql, "ADD COLUMN IF NOT EXISTS provider_key VARCHAR(30)")
+	require.NotContains(t, sql, "ADD COLUMN provider_key VARCHAR(30);")
+}
+
+func TestMigration118DoesNotForceOverwriteAuthSourceGrantDefaults(t *testing.T) {
+	content, err := FS.ReadFile("118_wechat_dual_mode_and_auth_source_defaults.sql")
+	require.NoError(t, err)
+
+	sql := string(content)
+	require.NotContains(t, sql, "UPDATE settings")
+	require.NotContains(t, sql, "SET value = 'false'")
+	require.True(t, strings.Contains(sql, "ON CONFLICT (key) DO NOTHING"))
+}
+
+func TestMigration119EnforcesOutTradeNoPartialUniqueIndex(t *testing.T) {
+	content, err := FS.ReadFile("119_enforce_payment_orders_out_trade_no_unique.sql")
+	require.NoError(t, err)
+
+	sql := string(content)
+	require.Contains(t, sql, "DROP INDEX IF EXISTS paymentorder_out_trade_no")
+	require.Contains(t, sql, "CREATE UNIQUE INDEX IF NOT EXISTS paymentorder_out_trade_no")
+	require.Contains(t, sql, "WHERE out_trade_no <> ''")
+}