# OpenSpec Change: enterprise-migration

- **Change ID**: enterprise-migration
- **Package**: `@suaveplan/migration`
- **Category**: universal
- **Target path**: `universal/database/migration`
- **Status**: PROPOSED
- **Date**: 2026-04-24
- **Reference spec**: `/mnt/s/web/suaveplan/enterprise/migration.md`

---

## Summary

Deliver `@suaveplan/migration` on the genesis branch from scratch at enterprise quality. The package provides a database-agnostic schema migration runner: a `MigrationRunner` that orchestrates up/down execution, a pluggable `MigrationStoreAdapter` for ledger persistence, a `MigrationLockAdapter` interface (memory + distributed), a dry-run reporter, a status dashboard, an optional batch migrator for multi-target rollouts, and a SurrealDB adapter. Genesis adds structured errors via `@suaveplan/error`, Zod schemas for all public types, OTel instrumentation, `AbortSignal` cancellation, logger injection via `@suaveplan/logger`, event bus integration via `@suaveplan/events`, property-based tests (fast-check), and a mitata benchmark suite. The migration runner previously bundled inside `@suaveplan/surrealdb` is now a standalone package consuming `@suaveplan/db`'s `DatabaseAdapter` interface.

---

## Current-state audit (genesis)

The package does not exist on genesis yet — this is a fresh build. No prior source, no test results, no coverage data.

---

## Available workspace deps on genesis

| Package | Role |
|---|---|
| `@suaveplan/error` (`workspace:^`) | Base class for `MigrationError`; `defineCodes` for `MIGRATION.*` codes |
| `@suaveplan/types` (`workspace:^`) | `LoggerLike`, `Clock`, `DatabaseLike` |
| `@suaveplan/db` (`workspace:^`) | `DatabaseAdapter` interface consumed by `DatabaseMigrationStore` and `SurrealDbAdapter` |
| `@suaveplan/logger` (`workspace:^`) | `LoggerLike` structured logging throughout the runner |
| `@suaveplan/events` (`workspace:^`) | `EventBus` for migration lifecycle events (before/after each step) |
| `zod` (`catalog:forms`) | Zod schemas for all public option types |
| `@opentelemetry/api` (`catalog:observability`) | Spans + counters on runner, planner, executor |
| `tslib` (`catalog:build`) | Runtime helpers |

Dev deps: `vitest`, `@vitest/coverage-istanbul`, `fast-check`, `mitata` (all `catalog:testing`), `@suaveplan/testing` (`workspace:^`), `@suaveplan/db-sqlite workspace:^` (integration test store backend).

---

## Preserved public API surface (from main branch)

### Runner

```ts
class MigrationRunner {
  constructor(config: MigrationRunnerConfig)
  up(options?: RunOptions): Promise<MigrationResult>
  down(options?: RunOptions & { steps?: number }): Promise<MigrationResult>
  status(): Promise<MigrationStatus[]>
  validate(): Promise<ValidationResult>
}

interface MigrationRunnerConfig {
  migrations: Migration[]
  store: MigrationStoreAdapter
  lock?: MigrationLockAdapter
  logger?: LoggerLike
  dryRun?: boolean
  checksumValidation?: boolean
}

interface RunOptions { signal?: AbortSignal; target?: string }
```

### Types

```ts
interface Migration {
  id: string
  name: string
  up: (ctx: MigrationContext) => Promise<void>
  down?: (ctx: MigrationContext) => Promise<void>
  checksum?: string
}

interface MigrationContext { db: DatabaseAdapter; logger: LoggerLike }

type MigrationDirection = 'up' | 'down'
type MigrationStatus = 'pending' | 'applied' | 'failed' | 'rolled-back'

interface MigrationRecord { id: string; name: string; appliedAt: number; checksum?: string; direction: MigrationDirection }

interface MigrationPlan { toApply: Migration[]; toRollback: Migration[] }

interface MigrationResult { applied: string[]; skipped: string[]; failed: string[]; direction: MigrationDirection; dryRun: boolean }

interface ValidationError { migrationId: string; message: string }
interface ValidationResult { valid: boolean; errors: ValidationError[] }
```

### Store adapters

```ts
interface MigrationStoreAdapter {
  getApplied(): Promise<MigrationRecord[]>
  record(record: MigrationRecord): Promise<void>
  remove(id: string): Promise<void>
  clear(): Promise<void>
}

class MemoryMigrationStore implements MigrationStoreAdapter
class DatabaseMigrationStore implements MigrationStoreAdapter {
  constructor(config: DatabaseStoreConfig)
}

interface DatabaseStoreConfig { adapter: DatabaseAdapter; tableName?: string }
interface DatabaseAdapter { query<T>(sql: string, params?: unknown[]): Promise<T[]> }
```

### Lock adapters

```ts
interface MigrationLockAdapter {
  acquire(timeout?: number): Promise<boolean>
  release(): Promise<void>
  isLocked(): Promise<boolean>
}

class MemoryMigrationLock implements MigrationLockAdapter
class DistributedMigrationLock implements MigrationLockAdapter {
  constructor(config: DistributedLockConfig)
}

interface DistributedLockAdapter { acquire(key: string, ttl: number): Promise<boolean>; release(key: string): Promise<void> }
interface DistributedLockConfig { adapter: DistributedLockAdapter; key?: string; ttl?: number }
class InMemoryDistributedLockAdapter implements DistributedLockAdapter
class RedisDistributedLock implements MigrationLockAdapter {
  constructor(config: RedisLockConfig)
}
interface RedisLockClient { set(key: string, value: string, options: object): Promise<string | null>; del(key: string): Promise<number> }
interface RedisLockConfig { client: RedisLockClient; key?: string; ttl?: number }
```

### Planner

```ts
function planUp(all: Migration[], applied: MigrationRecord[]): MigrationPlan
function planDown(all: Migration[], applied: MigrationRecord[], steps?: number): MigrationPlan
function sortMigrations(migrations: Migration[]): Migration[]
function checksumMigration(migration: Migration): string
```

### Executor

```ts
class MigrationExecutor {
  constructor(options: ExecutorOptions)
  execute(plan: MigrationPlan, direction: MigrationDirection, options?: RunOptions): Promise<MigrationResult>
}
```

### Dry-run reporter

```ts
class DryRunReporter {
  constructor()
  record(entry: DryRunEntry): void
  report(): DryRunReport
}

interface DryRunEntry { migrationId: string; direction: MigrationDirection; riskLevel: RiskLevel; reason?: string }
interface DryRunReport { entries: DryRunEntry[]; totalRisk: RiskLevel; summary: string }
type RiskLevel = 'low' | 'medium' | 'high'
```

### Status dashboard

```ts
class MigrationStatusDashboard {
  constructor(config: StatusConfig)
  getAll(): Promise<ExtendedMigrationStatus[]>
  getSummary(): Promise<MigrationSummary>
  healthCheck(): Promise<MigrationHealthCheck>
  getHistory(id: string): Promise<MigrationHistoryEntry[]>
}
```

### Batch migrator

```ts
class BatchMigrator {
  constructor(config: BatchMigratorConfig)
  run(options?: RunOptions): Promise<BatchMigrationResult>
}

interface BatchMigratorConfig { targets: Array<{ name: string; runner: MigrationRunner }>; concurrency?: number }
interface BatchMigrationResult { results: Map<string, MigrationResult>; failed: string[]; succeeded: string[] }
```

### SurrealDB adapter

```ts
class SurrealDbAdapter implements DatabaseAdapter {
  constructor(config: SurrealDbAdapterConfig)
  query<T>(sql: string, params?: unknown[]): Promise<T[]>
}

interface SurrealDbAdapterConfig { db: unknown /* Surreal instance */ }
```

### Events

```ts
interface MigrationEventMap {
  'migration:before': { migration: Migration; direction: MigrationDirection }
  'migration:after': { migration: Migration; direction: MigrationDirection; durationMs: number }
  'migration:failed': { migration: Migration; direction: MigrationDirection; error: Error }
  'migration:plan': { plan: MigrationPlan; direction: MigrationDirection }
}

const migrationEvents: EventBus<MigrationEventMap>
```

### Error codes

```ts
type MigrationErrorCode =
  | 'MIGRATION_FAILED'
  | 'MIGRATION_LOCK_TIMEOUT'
  | 'MIGRATION_CHECKSUM_MISMATCH'
  | 'MIGRATION_NOT_FOUND'
  | 'MIGRATION_STORE_ERROR'
  | 'MIGRATION_PLAN_INVALID'
  | 'MIGRATION_ABORTED'
  | 'MIGRATION_DRY_RUN'
```

---

## New additions for genesis

### 1. Structured `MigrationError`

`MigrationError` extends `SuaveplanError` from `@suaveplan/error` carrying a `MigrationErrorCode` discriminant. Internal throw sites use named factory helpers.

### 2. Zod schemas

- `MigrationRunnerConfigSchema`
- `RunOptionsSchema`
- `BatchMigratorConfigSchema`
- `DatabaseStoreConfigSchema`
- `DistributedLockConfigSchema`
- `RedisLockConfigSchema`

### 3. Logger injection

`MigrationRunnerConfig.logger` is now typed as `LoggerLike` (from `@suaveplan/types`). All runner, planner, and executor operations emit structured log entries at `debug` / `info` / `error` levels with migration ID, direction, and duration.

### 4. Event bus integration

`MigrationRunnerConfig` gains an optional `events?: EventBus<MigrationEventMap>`. When provided the runner emits `migration:before`, `migration:after`, `migration:failed`, `migration:plan` events. The exported `migrationEvents` singleton is available for packages that do not control runner construction.

### 5. OTel instrumentation

| Operation | Signal |
|---|---|
| `runner.up` / `runner.down` | span `migration.run`, attribute `migration.direction`, `migration.count` |
| per-migration execution | span `migration.execute`, attribute `migration.id`, histogram `migration.duration_ms` |
| `runner.status` | counter `migration.status_query_total` |
| `batchMigrator.run` | span `migration.batch`, attribute `migration.target_count` |

### 6. Checksum validation

`checksumMigration` hashes the serialised `up` function body. When `checksumValidation: true` (default on `MigrationRunner`), mismatched checksums between the registered migration and the store record throw `MigrationError(MIGRATION_CHECKSUM_MISMATCH)` before applying.

### 7. Property-based tests (fast-check)

- `planUp` idempotency: applying `planUp` to an already fully-applied set returns an empty `toApply` list.
- `sortMigrations` stability: for any permutation of N migrations, `sortMigrations` returns the same order.
- `checksumMigration` determinism: calling checksum on the same migration object twice returns the same string.
- `BatchMigrator` partial failure: if K of N targets fail, the result has exactly K failed entries.

### 8. Benchmark suite

- `planUp_100`: plan for 100 pending migrations.
- `runner_up_10_memory`: run 10 no-op migrations against `MemoryMigrationStore`.
- `checksumMigration_1k`: 1000 checksum computations.

---

## File layout

```text
universal/database/migration/
  package.json
  tsconfig.json
  vitest.config.ts
  src/
    index.ts                              # Public barrel
    error-codes.ts                        # MIGRATION.* codes
    migration-events.ts                   # migrationEvents singleton + MigrationEventMap
    constants/
      index.ts                            # DEFAULT_TABLE_NAME, DEFAULT_LOCK_TTL
    types/
      migration.types.ts                  # All public TS interfaces
      migration.types.md
      schemas.ts                          # Zod schemas
      schemas.md
    planner/
      migration-planner/
        migration-planner.ts              # planUp, planDown, sortMigrations, checksumMigration
        migration-planner.md
        migration-planner.test.ts
        index.ts
    runner/
      migration-runner/
        migration-runner.ts               # MigrationRunner
        migration-runner.md
        migration-runner.types.ts
        migration-runner.test.ts
        index.ts
      migration-executor/
        migration-executor.ts             # MigrationExecutor
        migration-executor.md
        migration-executor.test.ts
        index.ts
      dry-run-reporter/
        dry-run-reporter.ts
        dry-run-reporter.md
        dry-run-reporter.test.ts
        index.ts
    store/
      memory-store/
        memory-store.ts                   # MemoryMigrationStore
        memory-store.md
        memory-store.test.ts
        index.ts
      database-store/
        database-store.ts                 # DatabaseMigrationStore
        database-store.md
        database-store.types.ts
        database-store.test.ts
        index.ts
    lock/
      memory-lock/
        memory-lock.ts
        memory-lock.md
        memory-lock.test.ts
        index.ts
      distributed-lock/
        distributed-lock.ts
        distributed-lock.md
        distributed-lock.types.ts
        distributed-lock.test.ts
        index.ts
      redis-lock/
        redis-lock.ts
        redis-lock.md
        redis-lock.types.ts
        redis-lock.test.ts
        index.ts
    status/
      migration-status/
        migration-status.ts               # MigrationStatusDashboard
        migration-status.md
        migration-status.types.ts
        migration-status.test.ts
        index.ts
    batch/
      batch-migrator/
        batch-migrator.ts
        batch-migrator.md
        batch-migrator.types.ts
        batch-migrator.test.ts
        index.ts
    adapters/
      surrealdb-adapter/
        surrealdb-adapter.ts
        surrealdb-adapter.md
        surrealdb-adapter.types.ts
        surrealdb-adapter.test.ts
        index.ts
    __benchmarks__/
      migration.bench.ts
  tests/
    integration.test.ts                   # Full up/down cycle with SQLite store (db-sqlite)
    property.test.ts                      # fast-check property tests
```

---

## Impact

**Downstream packages**: any package that manages database schema evolution. `@suaveplan/surrealdb` provides a `SurrealAdapter` that implements `DatabaseAdapter`; `@suaveplan/migration`'s `SurrealDbAdapter` wraps that for the migration store.

**Breaking changes from main-branch API**: none. New optional fields (`events`, `signal`) are additive.

**Workspace dep prerequisites**: `@suaveplan/error`, `@suaveplan/types`, `@suaveplan/db`, `@suaveplan/logger`, `@suaveplan/events` must be published to Verdaccio before this package can be built or tested.