H-60: harden Captain migration rollback and concurrency (#10)

Co-authored-by: Rogee <rogee@ipao.vip>

backend/internal/database/captain_binding_migration_test.go

@@ -0,0 +1,86 @@
+package database
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/driver/postgres"
+	"gorm.io/gorm"
+	"gorm.io/gorm/logger"
+)
+
+func TestCaptainBindingMigrationDeduplicatesAndRejectsDown(t *testing.T) {
+	if os.Getenv("GOCHAT_TEST_DB") == "sqlite" {
+		t.Skip("requires PostgreSQL migration semantics")
+	}
+	dsn := os.Getenv("GOCHAT_TEST_DB_URL")
+	if dsn == "" {
+		dsn = "host=localhost port=5432 user=postgres password=postgres dbname=gochat_test sslmode=disable"
+	}
+	db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{Logger: logger.Default.LogMode(logger.Silent)})
+	require.NoError(t, err)
+	sqlDB, err := db.DB()
+	require.NoError(t, err)
+	sqlDB.SetMaxOpenConns(1)
+	t.Cleanup(func() { _ = sqlDB.Close() })
+
+	schema := "captain_migration_" + time.Now().Format("20060102150405000000000")
+	require.NoError(t, db.Exec("CREATE SCHEMA "+schema).Error)
+	t.Cleanup(func() { _ = db.Exec("DROP SCHEMA " + schema + " CASCADE").Error })
+	require.NoError(t, db.Exec("SET search_path TO "+schema).Error)
+	require.NoError(t, db.Exec(`
+		CREATE TABLE agent_bots (id BIGINT PRIMARY KEY, account_id BIGINT, bot_type TEXT, config JSONB);
+		CREATE TABLE agent_bot_inboxes (id BIGINT PRIMARY KEY, agent_bot_id BIGINT, inbox_id BIGINT);
+		CREATE TABLE captain_inboxes (id BIGINT PRIMARY KEY, inbox_id BIGINT, deleted_at TIMESTAMPTZ);
+		CREATE TABLE conversations (id BIGINT PRIMARY KEY, assignee_agent_bot_id BIGINT);
+		CREATE TABLE agent_bot_presence_events (id BIGINT PRIMARY KEY, agent_bot_id BIGINT);
+		CREATE TABLE bot_rules (id BIGINT PRIMARY KEY, agent_bot_id BIGINT);
+		CREATE TABLE bot_trigger_configs (id BIGINT PRIMARY KEY, agent_bot_id BIGINT);
+		INSERT INTO agent_bots VALUES
+			(10, 1, 'captain', '{"assistant_id":7}'),
+			(11, 1, 'captain', '{"assistant_id":7}');
+		INSERT INTO agent_bot_inboxes VALUES (20, 10, 42), (21, 11, 42);
+		INSERT INTO captain_inboxes VALUES (30, 42, NULL), (31, 42, NULL);
+		INSERT INTO conversations VALUES (40, 11);
+		INSERT INTO agent_bot_presence_events VALUES (50, 11);
+		INSERT INTO bot_rules VALUES (60, 11);
+		INSERT INTO bot_trigger_configs VALUES (70, 11);
+	`).Error)
+
+	up, err := os.ReadFile(filepath.Join("..", "..", "migrations", "000079_make_captain_bindings_unique.up.sql"))
+	require.NoError(t, err)
+	require.NoError(t, db.Transaction(func(tx *gorm.DB) error { return tx.Exec(string(up)).Error }))
+
+	for _, table := range []string{"agent_bots", "agent_bot_inboxes", "captain_inboxes"} {
+		var count int64
+		require.NoError(t, db.Table(table).Count(&count).Error)
+		assert.Equal(t, int64(1), count, table)
+	}
+	for table, column := range map[string]string{
+		"conversations":             "assignee_agent_bot_id",
+		"agent_bot_presence_events": "agent_bot_id",
+		"bot_rules":                 "agent_bot_id",
+		"bot_trigger_configs":       "agent_bot_id",
+	} {
+		var botID int64
+		require.NoError(t, db.Table(table).Select(column).Scan(&botID).Error)
+		assert.Equal(t, int64(10), botID, table)
+	}
+	for table, index := range map[string]string{
+		"agent_bots":        "idx_agent_bots_captain_assistant",
+		"agent_bot_inboxes": "idx_agent_bot_inboxes_bot_inbox",
+		"captain_inboxes":   "idx_captain_inboxes_active_inbox",
+	} {
+		assert.True(t, db.Migrator().HasIndex(table, index), index)
+	}
+
+	down, err := os.ReadFile(filepath.Join("..", "..", "migrations", "000079_make_captain_bindings_unique.down.sql"))
+	require.NoError(t, err)
+	err = db.Transaction(func(tx *gorm.DB) error { return tx.Exec(string(down)).Error })
+	require.ErrorContains(t, err, "migration 000079 is irreversible")
+	assert.True(t, db.Migrator().HasColumn("agent_bots", "captain_assistant_id"))
+}