# OpenSpec Change: enterprise-search

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

---

## Summary

Deliver `@suaveplan/search` on the genesis branch from scratch at enterprise quality. The package provides universal full-text and fuzzy search primitives: a pluggable `SearchEngine` interface, built-in in-memory engine with inverted-index full-text and trigram-based fuzzy matching, cursor and offset pagination via `@suaveplan/pagination`, structured errors, OTel instrumentation, Zod-validated query schemas, and property-based correctness guarantees.

---

## Current-state audit (genesis)

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

---

## Available workspace deps on genesis

| Package | Role |
|---|---|
| `@suaveplan/error` (`workspace:^`) | Base class for `SearchError`; `defineCodes` for `SEARCH.*` codes |
| `@suaveplan/types` (`workspace:^`) | `LoggerLike`, `Clock` injection interfaces |
| `@suaveplan/pagination` (`workspace:^`) | Cursor and offset pagination helpers for search results |
| `zod` (`catalog:forms`) | Zod schemas for query, filter, and result types |
| `@opentelemetry/api` (`catalog:observability`) | Spans, counters, histograms on search, index, and suggest operations |
| `tslib` (`catalog:build`) | Runtime helpers |

Dev deps: `vitest`, `@vitest/coverage-istanbul`, `fast-check`, `mitata` (all `catalog:testing`).

---

## Public API surface

### Engine interface

```ts
interface SearchEngine<T extends SearchDocument> {
  readonly name: string
  index(documents: T[], options?: IndexOptions): Promise<void>
  search(query: SearchQuery, options?: SearchOptions): Promise<SearchResult<T>>
  suggest(prefix: string, options?: SuggestOptions): Promise<string[]>
  remove(ids: string[]): Promise<void>
  clear(): Promise<void>
}

interface SearchDocument {
  id: string
  [field: string]: unknown
}

interface SearchQuery {
  text?: string
  filters?: SearchFilter[]
  sort?: SortSpec[]
  pagination?: PaginationSpec
}

interface SearchFilter {
  field: string
  op: "eq" | "neq" | "gt" | "gte" | "lt" | "lte" | "in" | "contains"
  value: unknown
}

interface SortSpec {
  field: string
  direction: "asc" | "desc"
}

interface PaginationSpec {
  type: "cursor" | "offset"
  cursor?: string
  offset?: number
  limit: number
}

interface SearchResult<T extends SearchDocument> {
  hits: SearchHit<T>[]
  total: number
  cursor?: string
  durationMs: number
  facets?: Record<string, FacetBucket[]>
}

interface SearchHit<T extends SearchDocument> {
  document: T
  score: number
  highlights?: Record<string, string[]>
}

interface FacetBucket {
  value: string
  count: number
}
```

### In-memory engine

```ts
interface MemorySearchEngineOptions<T extends SearchDocument> {
  fields: FieldConfig<T>[]
  stemming?: boolean
  stopWords?: string[]
  fuzzyThreshold?: number
  logger?: LoggerLike
  clock?: Clock
}

interface FieldConfig<T extends SearchDocument> {
  name: keyof T & string
  type: "text" | "keyword" | "number" | "date" | "boolean"
  searchable?: boolean
  sortable?: boolean
  facetable?: boolean
  weight?: number
}

function createMemorySearchEngine<T extends SearchDocument>(
  options: MemorySearchEngineOptions<T>
): SearchEngine<T>
```

### Text utilities

```ts
// Tokenization, normalization, stemming
function tokenize(text: string, options?: TokenizeOptions): string[]
function normalize(token: string): string
function buildTrigrams(text: string): Set<string>
function trigramSimilarity(a: string, b: string): number

// Scoring
function tfIdfScore(tf: number, idf: number): number
function bm25Score(options: Bm25Options): number
```

### Error handling

```ts
class SearchError extends SuaveplanError<SearchErrorCode>

type SearchErrorCode =
  | "SEARCH_INDEX_FAILED"
  | "SEARCH_QUERY_INVALID"
  | "SEARCH_ENGINE_NOT_READY"
  | "SEARCH_FIELD_UNKNOWN"
  | "SEARCH_CURSOR_INVALID"

function registerSearchErrorCodes(): void
```

### Zod schemas

```ts
const SearchQuerySchema: ZodSchema
const SearchFilterSchema: ZodSchema
const SearchResultSchema: ZodSchema
const MemorySearchEngineOptionsSchema: ZodSchema
```

---

## New additions for genesis

### 1. BM25 scoring

The in-memory engine uses BM25 (k1=1.2, b=0.75) as its default ranking algorithm, configurable via `scoringOptions` in `MemorySearchEngineOptions`.

### 2. Faceted search

When `FieldConfig.facetable = true`, search results include `facets` with bucket counts per facetable field. Supports up to 100 distinct values per field in memory.

### 3. Highlight extraction

Matched terms are highlighted in the original field text using a configurable `<mark>` wrapper (or caller-supplied `highlightTag`). Applied to all `searchable` text fields.

### 4. OTel instrumentation

- `engine.index` — span `search.index`, attributes: `search.document_count`
- `engine.search` — span `search.search`, attributes: `search.query_text`, `search.filter_count`, `search.hit_count`; histogram `search.query_duration_ms`
- `engine.suggest` — span `search.suggest`, attributes: `search.prefix_length`
- Counters: `search.queries_total`, `search.index_operations_total`

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

- Index then search: every indexed document is retrievable by exact ID match
- Filter monotonicity: adding a filter never increases the result count
- Trigram similarity symmetry: `sim(a, b) === sim(b, a)` for all strings
- Pagination completeness: paginating through all results yields the same total as a single unbounded query

### 6. Benchmark suite (`src/__benchmarks__/`)

- Index 1k, 10k, 100k documents
- Search with single text query on indexed dataset
- Suggest with 3-character prefix

---

## File layout

```text
universal/data/search/
  package.json
  tsconfig.json
  vitest.config.ts
  src/
    index.ts
    error-codes.ts
    constants/
      index.ts
    types/
      common.ts
      common.md
    engine/
      search-engine/
        search-engine.ts
        search-engine.md
        search-engine.types.ts
        search-engine.test.ts
        index.ts
      memory-engine/
        memory-engine.ts
        memory-engine.md
        memory-engine.types.ts
        memory-engine.test.ts
        index.ts
    text/
      tokenizer/
        tokenizer.ts
        tokenizer.md
        tokenizer.test.ts
        index.ts
      trigram/
        trigram.ts
        trigram.md
        trigram.test.ts
        index.ts
      scorer/
        scorer.ts
        scorer.md
        scorer.test.ts
        index.ts
    __benchmarks__/
      search.bench.ts
  tests/
    integration.test.ts
    property.test.ts
```

---

## Impact

**Downstream packages**: any package needing full-text or fuzzy search on in-memory datasets. No existing genesis package depends on it yet.

**Workspace dep prerequisites**: `@suaveplan/error`, `@suaveplan/types`, `@suaveplan/pagination` must be published to Verdaccio before this package can be built.

**Breaking changes**: none (new package).