test(engine-doubles): add the findOne slice to check:engine-double-contract and adopt assertEngineFindOnePredicate across the re-measured 211-file remainder (#12560)

* test(engine-doubles): adopt assertEngineFindOnePredicate across 212 files / 245 findOne doubles

The adoption half of #12068. Discovery was NOT re-derived by hand: the
population is `check:engine-double-contract`'s own reported (file, line)
answers with a findOne slice installed, so the batch cannot be narrower or
wider than what the gate scores.

`@objectstack/service-datasource` gains `@objectstack/metadata-core` as a
devDependency — the one package in the remainder that depended on neither home
of the predicate. Acyclic, measured rather than cited: `turbo run build
--filter=@objectstack/service-datasource --dry` exits 0 with zero
circular-dependency reports and metadata-core present in the graph.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01W6HFzyH98W1YaQXhJUJt6o

* wip(engine-doubles): recovered uncommitted gate half from a stalled dispatch

NOT REVIEWED. The dispatch that wrote this stalled before committing or
pushing; this commit exists only so the work survives the container, and the
resuming dev is expected to inspect it, not to trust it.

Contents as found on disk: the findOne slice added to check-engine-double-contract's
SLICES table (assertEngineFindOnePredicate / resolveEngineFindOnePredicate,
origin #4419), plus the regenerated baseline and pinned ledgers. No gate run,
no test run, and no ablation was performed against it here.

* fix(engine-doubles): close the two defects the recovered findOne sweep left, and alias metadata-core in service-datasource

Supersedes the "NOT REVIEWED" disclaimer on 88784b7: the gate half and the
211-file adoption below it have now been run, ablated and re-measured. Three
things this commit changes, all of them found by running what that commit never
ran.

1. TS2345 in service-messaging. `delivery-headers-at-rest.integration.test.ts`
   passed the fake's `q: unknown` straight into the predicate, whose parameter is
   `EngineFindOneQueryInput | null | undefined`. vitest never type-checks, so the
   suite was green and `tsc --noEmit` was red — the one direction a test-only
   sweep can go wrong invisibly. Cast at the call, matching the sibling
   `assertEngineUpdateDispatch(d as any, q as any)` pin three lines below it.

2. service-datasource's engine double reached `@objectstack/metadata-core`
   through `dist/`. `check:test-source-alias` names the repair and refuses the
   alternative: alias the specifier in the package's own vitest config, never
   widen the shrink-only registry. A pin resolved through a build artifact is
   pinned to whatever was last built rather than to the predicate beside it,
   which is the single failure a contract pin exists to prevent.

3. Import order in that same test file is now load-bearing, and says so.
   Aliasing metadata-core to source pulls its import graph into the package's
   resolution domain, which switches on the clocked-window rule for the whole
   package — and that rule then misreported a file that has paid its
   `@objectstack/spec/kernel` load at module top since #10120. Cause is a
   detector defect filed as #12555: the gate's import regex swallows a bare
   side-effect import whenever an `import … from …` follows it later in the
   file. Not worked around in the gate — the fix there needs its own
   `--self-test` cases — so the statement is placed where the detector reads it
   correctly, with a comment naming the constraint and the card that removes it.

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: os-warren

packages/core/src/utils/migration-journal.test.ts

@@ -27,7 +27,7 @@ import {
   assertEngineUpdateDispatch,
   type EngineDeleteDispatchInput,
   type EngineUpdateDispatchData,
-  type EngineUpdateDispatchInput,
+  type EngineUpdateDispatchInput, assertEngineFindOnePredicate,
 } from '@objectstack/metadata-core';
 import {
   runMigrationJournal,
@@ -85,6 +85,7 @@ class FakeEngine {
   }
 
   async findOne(objectName: string, query?: { where?: Record<string, unknown> }): Promise<FakeRow | null> {
+    assertEngineFindOnePredicate(objectName, query);
     return (await this.find(objectName, query))[0] ?? null;
   }
 

packages/mcp/src/__tests__/plugin.test.ts

@@ -2,6 +2,7 @@
 
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { MCPServerPlugin } from '../plugin.js';
+import { assertEngineFindOnePredicate, type EngineFindOneQueryInput } from '@objectstack/metadata-core';
 
 // ---------------------------------------------------------------------------
 // Mock PluginContext
@@ -69,7 +70,7 @@ function createMockMetadataService() {
 function createMockDataEngine() {
   return {
     find: vi.fn(async () => []),
-    findOne: vi.fn(async () => null),
+    findOne: vi.fn(async (object: string, query?: EngineFindOneQueryInput) => { assertEngineFindOnePredicate(object, query); return null; }),
     insert: vi.fn(),
     update: vi.fn(),
     delete: vi.fn(),

packages/mcp/src/mcp-stdio-tools.test.ts

@@ -41,7 +41,7 @@ import type { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
 import { MCPServerRuntime } from './mcp-server-runtime.js';
 import { MCPServerPlugin } from './plugin.js';
 import type { McpDataBridge } from './mcp-http-tools.js';
-import { assertEngineDeleteDispatch, assertEngineUpdateDispatch } from '@objectstack/metadata-core';
+import { assertEngineDeleteDispatch, assertEngineUpdateDispatch, assertEngineFindOnePredicate, type EngineFindOneQueryInput } from '@objectstack/metadata-core';
 
 // ---------------------------------------------------------------------------
 // A real stdio client: newline-delimited JSON-RPC over the transport's pipes
@@ -503,7 +503,7 @@ describe('#8034 plugin composition: os serve stdio wiring', () => {
       }),
       aggregate: vi.fn(async () => []),
       count: vi.fn(async () => 0),
-      findOne: vi.fn(async () => null),
+      findOne: vi.fn(async (object: string, query?: EngineFindOneQueryInput) => { assertEngineFindOnePredicate(object, query); return null; }),
     };
   }
 

packages/mcp/src/mcp-write-response-internal-fields.tripwire.test.ts

@@ -46,7 +46,7 @@ import type { ExecutionContext } from '@objectstack/spec/kernel';
 import type { IDataEngine, IMetadataService } from '@objectstack/spec/contracts';
 import { omitInternalFieldsFromWriteResponse } from '@objectstack/core';
 import { createStdioDataBridge } from './stdio-data-bridge.js';
-import { assertEngineDeleteDispatch, assertEngineUpdateDispatch } from '@objectstack/metadata-core';
+import { assertEngineDeleteDispatch, assertEngineUpdateDispatch, assertEngineFindOnePredicate, type EngineFindOneQueryInput } from '@objectstack/metadata-core';
 
 /** The value that must NEVER appear in any MCP response. */
 const SENTINEL = 'INTERNAL-SENTINEL-8497-NEVER-SERIALIZED';
@@ -81,7 +81,7 @@ function makeSentinelEngine(): IDataEngine {
   });
   return {
     find: vi.fn(async () => [storedRow()]),
-    findOne: vi.fn(async () => storedRow()),
+    findOne: vi.fn(async (object: string, query?: EngineFindOneQueryInput) => { assertEngineFindOnePredicate(object, query); return storedRow(); }),
     insert: vi.fn(async (_o: string, data: Record<string, unknown>) =>
       writtenRow((data?.id as string) ?? 'new-1', data)),
     update: vi.fn(async (_o: string, data: Record<string, unknown>, options?: any) => {

packages/mcp/src/plugin.record-resource-exposure.test.ts

@@ -50,7 +50,7 @@ import type { IMetadataService } from '@objectstack/spec/contracts';
 import type { MCPServerRuntime } from './mcp-server-runtime.js';
 import { MCPServerPlugin } from './plugin.js';
 import { enforceApiExposure, GATED_ACTIONS, type McpExposureError } from './stdio-data-bridge.js';
-import { assertEngineDeleteDispatch, assertEngineUpdateDispatch } from '@objectstack/metadata-core';
+import { assertEngineDeleteDispatch, assertEngineUpdateDispatch, assertEngineFindOnePredicate, type EngineFindOneQueryInput } from '@objectstack/metadata-core';
 
 // ---------------------------------------------------------------------------
 // A real stdio client: newline-delimited JSON-RPC over the transport's pipes
@@ -172,7 +172,7 @@ function fakeObjectQL() {
     }),
     aggregate: vi.fn(async () => []),
     count: vi.fn(async () => 0),
-    findOne: vi.fn(async () => null),
+    findOne: vi.fn(async (object: string, query?: EngineFindOneQueryInput) => { assertEngineFindOnePredicate(object, query); return null; }),
   };
 }
 

packages/mcp/src/stdio-data-bridge.exposure.test.ts

@@ -39,6 +39,7 @@ import { DATA_ACTION_TO_API_OPERATION } from '@objectstack/spec/data';
 import type { ExecutionContext } from '@objectstack/spec/kernel';
 import type { IDataEngine, IMetadataService } from '@objectstack/spec/contracts';
 import { createStdioDataBridge, GATED_ACTIONS, type McpExposureError } from './stdio-data-bridge.js';
+import { assertEngineFindOnePredicate, type EngineFindOneQueryInput } from '@objectstack/metadata-core';
 
 // ---------------------------------------------------------------------------
 // Doubles
@@ -54,7 +55,7 @@ import { createStdioDataBridge, GATED_ACTIONS, type McpExposureError } from './s
 function makeEngine(rows: Array<Record<string, unknown>> = [{ id: 'r1', title: 'row' }]) {
   return {
     find: vi.fn(async () => rows),
-    findOne: vi.fn(async () => rows[0] ?? null),
+    findOne: vi.fn(async (object: string, query?: EngineFindOneQueryInput) => { assertEngineFindOnePredicate(object, query); return rows[0] ?? null; }),
     insert: vi.fn(),
     update: vi.fn(),
     delete: vi.fn(),

packages/mcp/src/stdio-data-bridge.not-found.test.ts

@@ -23,12 +23,13 @@ import { describe, it, expect, vi } from 'vitest';
 import type { ExecutionContext } from '@objectstack/spec/kernel';
 import type { IDataEngine, IMetadataService } from '@objectstack/spec/contracts';
 import { createStdioDataBridge } from './stdio-data-bridge.js';
+import { assertEngineFindOnePredicate, type EngineFindOneQueryInput } from '@objectstack/metadata-core';
 
 /** An engine that resolves NO row for any id — every by-id write is a miss. */
 function makeEmptyEngine() {
   return {
     find: vi.fn(async () => []),
-    findOne: vi.fn(async () => null),
+    findOne: vi.fn(async (object: string, query?: EngineFindOneQueryInput) => { assertEngineFindOnePredicate(object, query); return null; }),
     insert: vi.fn(),
     update: vi.fn(),
     delete: vi.fn(),

packages/metadata-protocol/src/migrations/recorded-by-sentinel.test.ts

@@ -29,7 +29,7 @@ import { runMigrationJournal, readRunJournal } from '@objectstack/core';
 // package both sides already depend on, which is what makes this line legal.
 import {
   assertEngineDeleteDispatch,
-  assertEngineUpdateDispatch,
+  assertEngineUpdateDispatch, assertEngineFindOnePredicate,
 } from '@objectstack/metadata-core';
 import {
   createRecordedBySentinelPlan,
@@ -77,6 +77,7 @@ class FakeEngine {
   }
 
   async findOne(objectName: string, query?: { where?: Record<string, unknown> }): Promise<FakeRow | null> {
+    assertEngineFindOnePredicate(objectName, query);
     return (await this.find(objectName, query))[0] ?? null;
   }
 

packages/metadata-protocol/src/protocol-publish-drafts-advisories.test.ts

@@ -35,7 +35,7 @@
  */
 
 import { describe, expect, it } from 'vitest';
-import { assertEngineDeleteDispatch, assertEngineUpdateDispatch } from '@objectstack/metadata-core';
+import { assertEngineDeleteDispatch, assertEngineUpdateDispatch, assertEngineFindOnePredicate } from '@objectstack/metadata-core';
 import { ObjectStackProtocolImplementation } from './protocol.js';
 
 interface Row {
@@ -117,6 +117,7 @@ function makeStubEngine() {
 
     const engine: any = {
         async findOne(table: string, opts: { where: Record<string, unknown> }) {
+            assertEngineFindOnePredicate(table, opts);
             if (table === 'sys_metadata_history') {
                 return historyRows.find((h) => matchesHistory(h, opts.where)) ?? null;
             }

packages/metadata-protocol/src/protocol-publish-drafts-closure.test.ts

@@ -56,7 +56,7 @@ import { describe, expect, it, vi, beforeEach, afterEach } from 'vitest';
 // The producer's OWN write-verb dispatch decisions, so the fake engine below
 // cannot accept a call ObjectQL refuses. From `@objectstack/metadata-core`,
 // never from `@objectstack/objectql` — that import would close a cycle.
-import { assertEngineDeleteDispatch, assertEngineUpdateDispatch } from '@objectstack/metadata-core';
+import { assertEngineDeleteDispatch, assertEngineUpdateDispatch, assertEngineFindOnePredicate } from '@objectstack/metadata-core';
 import { ObjectStackProtocolImplementation } from './protocol.js';
 
 interface Row {
@@ -155,6 +155,7 @@ function makeStubEngine(options?: { liveObjects?: unknown[]; livePermissions?: u
 
     const engine: any = {
         async findOne(table: string, opts: { where: Record<string, unknown> }) {
+            assertEngineFindOnePredicate(table, opts);
             if (table === 'sys_metadata_history') {
                 return historyRows.find((h) => matchesHistory(h, opts.where)) ?? null;
             }