ModelSchemaProvider._loadModelSchema causes infinite recursion via ShimModelClass

[paddor]

Bug

ModelSchemaProvider._loadModelSchema(type) in @warp-drive/legacy@5.8.1 causes RangeError: Maximum call stack size exceeded.

Stack trace

handlers.js:11 Uncaught (in promise) RangeError: Maximum call stack size exceeded
    at invoke (handlers.js:11:27)
    at deprecate (deprecate.js:187:5)
    at Store.modelFor (index-CQP2NSqg.js:5823:26)
    at ModelSchemaProvider._loadModelSchema (schema-provider-DJCV_6AF.js:2127:35)
    at ModelSchemaProvider.fields (schema-provider-DJCV_6AF.js:2160:12)
    at DelegatingSchemaService.fields (migration-support.js:470:28)
    at get attributes (index-CQP2NSqg.js:5546:40)
    at ModelSchemaProvider._loadModelSchema (schema-provider-DJCV_6AF.js:2128:37)
    at ModelSchemaProvider.fields (schema-provider-DJCV_6AF.js:2160:12)

Root cause

In @warp-drive/legacy schema-provider, _loadModelSchema(type) calls this.store.modelFor(type). In @warp-drive/core 5.8.1, Store.prototype.modelFor returns a ShimModelClass (not the actual Model class). The ShimModelClass.get attributes() getter calls this.__store.schema.fields({type}), which goes through DelegatingSchemaService.fields() → ModelSchemaProvider.fields(). Since the schema isn't cached yet (we're still inside _loadModelSchema), fields() calls _loadModelSchema(type) again — infinite recursion.

The cycle:

1. _loadModelSchema(type) — line 2150: const modelClass = this.store.modelFor(type) → returns ShimModelClass
2. Line 2151: modelClass.attributes → triggers ShimModelClass.get attributes()
3. get attributes() calls store.schema.fields({type}) (core index line 5567)
4. → DelegatingSchemaService.fields() → ModelSchemaProvider.fields() → checks cache → miss → calls _loadModelSchema(type) → goto 1

Fix

Replace this.store.modelFor(type) with getModelFactory(this.store, type).class in _loadModelSchema. The getModelFactory function is already defined in the same file and returns the actual Model class from the Ember container — whose static attributes property doesn't call back into the schema system.

  _loadModelSchema(type) {
-   const modelClass = this.store.modelFor(type);
+   const factory = getModelFactory(this.store, type);
+   const modelClass = factory.class;
    const attributeMap = modelClass.attributes;

Versions

• @warp-drive/core: 5.8.1
• @warp-drive/legacy: 5.8.1
• ember-source: 6.8.0
• Using DelegatingSchemaService from @warp-drive/legacy/model/migration-support

Reproduction

Any app using DelegatingSchemaService with @warp-drive/legacy models that triggers store.schema.fields() or ModelSchemaProvider.fields() will hit this. It happens on the first access to any model's schema.

[runspired]

@paddor can you create a small reproduction? There is an recursion bug I've hit before when a schema is missing where we should error earlier to say so, but I've never hit it when schemas/models are actually present.

[paddor]

@runspired Here's a minimal reproduction:

Setup

npx ember-cli@6.8 new repro-app --skip-git --skip-npm
cd repro-app
npm install @warp-drive/core@5.8.1 @warp-drive/legacy@5.8.1 @warp-drive/json-api@5.8.1 @warp-drive/ember@5.8.1

1. Create models

app/models/post.js:

import Model, { attr, hasMany } from '@warp-drive/legacy/model';

export default class Post extends Model {
  @attr title;
  @hasMany('comment', { async: false, inverse: 'post' }) comments;
}

app/models/comment.js:

import Model, { attr, belongsTo } from '@warp-drive/legacy/model';

export default class Comment extends Model {
  @attr body;
  @belongsTo('post', { async: false, inverse: 'comments' }) post;
}

2. Create a store using DelegatingSchemaService

app/services/store.js:

import { Store, CacheHandler, RequestManager } from '@warp-drive/core';
import { SchemaService, registerDerivations, instantiateRecord, teardownRecord } from '@warp-drive/core/reactive';
import { DelegatingSchemaService, registerDerivations as registerLegacyDerivations } from '@warp-drive/legacy/model/migration-support';
import { JSONAPICache } from '@warp-drive/json-api';

export default class AppStore extends Store {
  constructor(owner) {
    super(owner);
    const manager = new RequestManager();
    manager.useCache(CacheHandler);
    this.requestManager = manager;
  }

  createSchemaService() {
    const schema = new SchemaService();
    registerDerivations(schema);
    registerLegacyDerivations(schema);
    return new DelegatingSchemaService(this, schema);
  }

  createCache(capabilities) {
    return new JSONAPICache(capabilities);
  }

  instantiateRecord(key, createArgs) {
    return instantiateRecord(this, key, createArgs);
  }

  teardownRecord(record) {
    return teardownRecord(record);
  }
}

3. Trigger schema access

app/routes/application.js:

import Route from '@ember/routing/route';
import { service } from '@ember/service';

export default class ApplicationRoute extends Route {
  @service store;

  model() {
    this.store.push({
      data: {
        type: 'post',
        id: '1',
        attributes: { title: 'Hello' },
        relationships: { comments: { data: [] } }
      }
    });
    return this.store.peekRecord('post', '1');
  }
}

Result

RangeError: Maximum call stack size exceeded
    at invoke (handlers.js)
    at deprecate (deprecate.js)
    at Store.modelFor (...)
    at ModelSchemaProvider._loadModelSchema (...)
    at ModelSchemaProvider.fields (...)
    at DelegatingSchemaService.fields (...)
    at get attributes (...)  // ShimModelClass.get attributes() calls store.schema.fields()
    at ModelSchemaProvider._loadModelSchema (...)
    ...

The cycle

_loadModelSchema(type) calls this.store.modelFor(type) → returns ShimModelClass (from @warp-drive/core) → ShimModelClass.get attributes() calls store.schema.fields({type}) → DelegatingSchemaService.fields() → ModelSchemaProvider.fields() → schema not cached yet → calls _loadModelSchema(type) again → ∞

The key is that Store.prototype.modelFor (in core) returns a ShimModelClass whose getters call back into the schema system, but ModelSchemaProvider._loadModelSchema doesn't set a cache entry before accessing modelClass.attributes.

[paddor]

Any updates?