package traceimpact

import (
	"os"
	"strings"
	"testing"
)

func TestMigrationDownKeepsDecisionLedger(t *testing.T) {
	b, err := os.ReadFile("../../deploy/postgres/goose/00059_2026-09-20-project-trace.sql")
	if err != nil {
		t.Fatal(err)
	}
	parts := strings.Split(string(b), "-- +goose Down")
	if len(parts) != 2 {
		t.Fatal("missing goose down")
	}
	down := strings.ToLower(parts[1])
	for _, forbidden := range []string{"drop table", "delete from", "truncate"} {
		if strings.Contains(down, forbidden) {
			t.Fatalf("down migration must not %s the trace ledger", forbidden)
		}
	}
	if !strings.Contains(down, "project_trace_edge_decisions") {
		t.Fatal("down comment should name the decision ledger it refuses to drop")
	}
}