open-brainy/tests/conformance/sparse-store-cut.test.ts

/**
 * @module tests/conformance/sparse-store-cut
 * @description THE SPARSE-STORE CUT (ruled 2026-08-12) — the shared
 * conformance rows both engines run: a WHERE filter naming a field NO row
 * carries is SERVED OPERATOR-TRUTHFULLY, never refused:
 *   eq / in / range / contains → []          (nothing carries it → nothing matches)
 *   ne / exists:false          → ALL rows    (equally true — blanket-empty here
 *                                             would be the outlawed silent wrong)
 *   exists:true                → []
 * orderBy on an unresolvable field KEEPS the hard refusal (no truthful
 * order exists). The did-you-mean demotes to a throttled WARN on the serve.
 * A fresh tenant's first filtered read is a correct empty answer — the
 * 341-red first-adopter class, closed.
 */
import { describe, it, expect, afterEach } from 'vitest'
import { Brainy, UnresolvableFieldError } from '../../src/index.js'
import { NounType } from '../../src/types/graphTypes.js'

const brains: Brainy[] = []
afterEach(async () => {
  for (const b of brains.splice(0)) await b.close().catch(() => {})
})

async function corpus(): Promise<{ brain: Brainy; ids: string[] }> {
  const b = new Brainy({ storage: { type: 'memory' }, requireSubtype: false })
  await b.init()
  brains.push(b)
  const ids: string[] = []
  for (let i = 0; i < 4; i++) {
    ids.push(
      await b.add({ data: `row ${i}`, type: NounType.Document, metadata: { carried: i } })
    )
  }
  return { brain: b, ids }
}

describe('sparse-store cut — operator-truthful serve on never-carried fields', () => {
  it('positive matches serve EMPTY: eq, in, range, contains', async () => {
    const { brain } = await corpus()
    expect(await brain.find({ where: { ghost: 'x' }, limit: 10 })).toEqual([])
    expect(await brain.find({ where: { ghost: { in: ['a', 'b'] } }, limit: 10 })).toEqual([])
    expect(await brain.find({ where: { ghost: { gt: 5 } }, limit: 10 })).toEqual([])
    expect(await brain.find({ where: { ghost: { exists: true } }, limit: 10 })).toEqual([])
  })

  it('negative matches serve ALL rows: ne and exists:false (the truth, not blanket-empty)', async () => {
    const { brain, ids } = await corpus()
    const ne = await brain.find({ where: { ghost: { ne: 'x' } }, limit: 10 })
    expect(ne.map((r) => r.id).sort()).toEqual([...ids].sort())
    const absent = await brain.find({ where: { ghost: { exists: false } }, limit: 10 })
    expect(absent.map((r) => r.id).sort()).toEqual([...ids].sort())
  })

  it('the fresh-tenant day-one shape: an EMPTY store answers its first filtered read with [], never a refusal', async () => {
    const b = new Brainy({ storage: { type: 'memory' }, requireSubtype: false })
    await b.init()
    brains.push(b)
    expect(await b.find({ where: { status: 'open' }, limit: 50 })).toEqual([])
    expect(await b.find({ where: { date: { gte: '2026-01-01' } }, limit: 50 })).toEqual([])
  })

  it('orderBy on an unresolvable field KEEPS the typed refusal', async () => {
    const { brain } = await corpus()
    await expect(
      brain.find({ where: { carried: { gte: 0 } }, orderBy: 'system.notAScalar', limit: 10 })
    ).rejects.toThrow(UnresolvableFieldError)
  })

  it('compound filters: the never-carried clause composes truthfully with carried clauses', async () => {
    const { brain, ids } = await corpus()
    // carried>=2 AND ghost ne 'x' → the carried>=2 rows (ne-clause = all).
    const both = await brain.find({
      where: { carried: { gte: 2 }, ghost: { ne: 'x' } },
      limit: 10
    })
    expect(both.map((r) => r.id).sort()).toEqual([ids[2], ids[3]].sort())
    // carried>=2 AND ghost eq 'x' → [] (eq-clause empties the intersection).
    expect(
      await brain.find({ where: { carried: { gte: 2 }, ghost: 'x' }, limit: 10 })
    ).toEqual([])
  })
})