extract getEntityRelations and use it in findMany to fix hot-reloading

Author: nikgraf

packages/hypergraph/src/entity/decodedEntitiesCache.ts

@@ -1,4 +1,17 @@
-import type { Any, AnyNoContext, Entity } from './types.js';
+import type { AnyNoContext, Entity } from './types.js';
+
+export type DecodedEntitiesCacheEntry = {
+  decoder: (data: unknown) => unknown;
+  type: AnyNoContext; // TODO should be the type of the entity
+  entities: Map<string, Entity<AnyNoContext>>; // holds all entities of this type
+  queries: Map<
+    string, // instead of serializedQueryKey as string we could also have the actual params
+    {
+      data: Array<Entity<AnyNoContext>>; // holds the decoded entities of this query and must be a stable reference and use the same reference for the `entities` array
+      listeners: Array<() => void>; // listeners to this query
+    }
+  >;
+};
 
 /*
 /*
@@ -13,18 +26,7 @@ import type { Any, AnyNoContext, Entity } from './types.js';
  */
 type DecodedEntitiesCache = Map<
   string, // type name
-  {
-    decoder: (data: unknown) => unknown;
-    type: Any; // TODO should be the type of the entity
-    entities: Map<string, Entity<AnyNoContext>>; // holds all entities of this type
-    queries: Map<
-      string, // instead of serializedQueryKey as string we could also have the actual params
-      {
-        data: Array<Entity<AnyNoContext>>; // holds the decoded entities of this query and must be a stable reference and use the same reference for the `entities` array
-        listeners: Array<() => void>; // listeners to this query
-      }
-    >;
-  }
+  DecodedEntitiesCacheEntry
 >;
 
 export const decodedEntitiesCache: DecodedEntitiesCache = new Map();

packages/hypergraph/src/entity/entity.ts

@@ -3,8 +3,8 @@ import * as VariantSchema from '@effect/experimental/VariantSchema';
 import * as Data from 'effect/Data';
 import * as Schema from 'effect/Schema';
 import { generateId } from '../utils/generateId.js';
-import { hasArrayField } from '../utils/hasArrayField.js';
 import { decodedEntitiesCache } from './decodedEntitiesCache.js';
+import { getEntityRelations } from './getEntityRelations.js';
 import type { AnyNoContext, Entity, Insert, Update } from './types.js';
 
 const {
@@ -98,34 +98,7 @@ export const subscribeToDocumentChanges = (handle: DocHandle<DocumentContent>) =
         const cacheEntry = decodedEntitiesCache.get(typeName);
         if (!cacheEntry) continue;
 
-        const relations: Record<string, Entity<AnyNoContext>> = {};
-        for (const [fieldName, field] of Object.entries(cacheEntry.type.fields)) {
-          // check if the type exists in the cach and is a proper relation
-          // TODO: what's the right way to get the name of the type?
-          // @ts-expect-error name is defined
-          const fieldCacheEntry = decodedEntitiesCache.get(field.name);
-          if (!fieldCacheEntry) continue;
-
-          const relationEntities: Array<Entity<AnyNoContext>> = [];
-
-          if (hasArrayField(entity, fieldName)) {
-            for (const relationEntityId of entity[fieldName]) {
-              const relationEntity = doc.entities?.[relationEntityId];
-              if (
-                !relationEntity ||
-                typeof relationEntity !== 'object' ||
-                !('@@types@@' in relationEntity) ||
-                !Array.isArray(relationEntity['@@types@@'])
-              )
-                continue;
-
-              relationEntities.push({ ...relationEntity, id: relationEntityId });
-            }
-          }
-
-          relations[fieldName] = relationEntities;
-        }
-
+        const relations = getEntityRelations(entity, cacheEntry.type, doc);
         const decoded = cacheEntry.decoder({
           ...entity,
           ...relations,
@@ -294,16 +267,19 @@ export function findMany<const S extends AnyNoContext>(
   // @ts-expect-error name is defined
   const typeName = type.name;
 
-  // TODO: Instead of this insane filtering logic, we should be keeping track of the entities in
-  // an index and store the decoded values instead of re-decoding over and over again.
-  const entities = handle.docSync()?.entities ?? {};
+  const doc = handle.docSync();
+  if (!doc) {
+    return [];
+  }
+  const entities = doc.entities ?? {};
   const filtered: Array<Entity<S>> = [];
   for (const id in entities) {
     const entity = entities[id];
     if (typeof entity === 'object' && entity != null && '@@types@@' in entity) {
       const types = entity['@@types@@'];
       if (Array.isArray(types) && types.includes(typeName)) {
-        filtered.push({ ...decode({ ...entity, id }), type: typeName });
+        const relations = getEntityRelations(entity, type, doc);
+        filtered.push({ ...decode({ ...entity, ...relations, id }), type: typeName });
       }
     }
   }

packages/hypergraph/src/entity/getEntityRelations.ts

@@ -0,0 +1,38 @@
+import { hasArrayField } from '../utils/hasArrayField.js';
+import type { DocumentContent } from './index.js';
+import type { AnyNoContext, Entity } from './types.js';
+
+export const getEntityRelations = <const S extends AnyNoContext>(
+  entity: Entity<AnyNoContext>,
+  type: S,
+  doc: DocumentContent,
+) => {
+  const relations: Record<string, Entity<AnyNoContext>> = {};
+  for (const [fieldName, field] of Object.entries(type.fields)) {
+    // TODO: this check is a hack atm, instead check if it is a class instead of specific name
+    // TODO: what's the right way to get the name of the type?
+    // @ts-expect-error name is defined
+    if (field.name !== 'ArrayClass') continue;
+
+    const relationEntities: Array<Entity<AnyNoContext>> = [];
+
+    if (hasArrayField(entity, fieldName)) {
+      for (const relationEntityId of entity[fieldName]) {
+        const relationEntity = doc.entities?.[relationEntityId];
+        if (
+          !relationEntity ||
+          typeof relationEntity !== 'object' ||
+          !('@@types@@' in relationEntity) ||
+          !Array.isArray(relationEntity['@@types@@'])
+        )
+          continue;
+
+        relationEntities.push({ ...relationEntity, id: relationEntityId });
+      }
+    }
+
+    relations[fieldName] = relationEntities;
+  }
+
+  return relations;
+};