findOne still returning array in angular-db

[kenjiqq]

• I've validated the bug against the latest version of DB packages

Describe the bug
In angular-db when using findOne in live query it is still returning an array of elements

To Reproduce
Use findOne on any live query

import { Component, inject } from '@angular/core';
import { injectLiveQuery } from '@tanstack/angular-db';
import { eq } from '@tanstack/db';
import { Transtackdb } from '../transtackdb';
import { JsonPipe } from '@angular/common';

@Component({
  selector: 'app-tanstackdb',
  imports: [
    JsonPipe
  ],
  template: `
    <div>Status: {{ query.status() }}</div>
    <div>Loading: {{ query.isLoading() }}</div>
    <div>Ready: {{ query.isReady() }}</div>
    <div>Error: {{ query.isError() }}</div>
    <div>Total: {{ query.data().length }}</div>
    <ul>
      {{ query.data() | json }}
    </ul>
  `,
})
export class Tanstackdb {
  tanstackDb = inject(Transtackdb);

  query = injectLiveQuery((q) =>
    q.from({ todo: this.tanstackDb.todoCollection })
      .where(({ todo }) => eq(todo.id, 1))
      .findOne(),
  );
}

import { inject, Injectable } from '@angular/core';
import { QueryClient } from '@tanstack/angular-query-experimental';
import { createCollection } from '@tanstack/db';
import { queryCollectionOptions } from '@tanstack/query-db-collection';

export type Todo = {
  id: number;
  text: string;
  completed: boolean;
};

const mockData: Todo[] = [
  {
    id: 1,
    text: 'Learn Tanstack DB',
    completed: false,
  },
  {
    id: 2,
    text: 'Build something awesome',
    completed: false,
  },
];

@Injectable({
  providedIn: 'root',
})
export class Transtackdb {
  queryClient = inject(QueryClient);
  todoCollection = createCollection(
    queryCollectionOptions({
      queryKey: ['todos'],
      queryClient: this.queryClient,
      queryFn: async (): Promise<Todo[]> => {
        const response = await new Promise<Todo[]>((resolve) => {
          resolve(mockData);
        });
        return response;
      },
      getKey: (item) => item.id,
    }),
  );
}

Outputs
Status: ready
Loading: false
Ready: true
Error: false
Total: 1
[ { "id": 1, "text": "Learn Tanstack DB", "completed": false } ]

Expected behavior
A single object not an array with objects

Desktop (please complete the following information):

OS: Mac
Browser Chrome
"@tanstack/angular-db": "0.1.52",

[kevin-dp]

/reproduce

[claude]

I've reproduced and fixed this issue.

Root cause: The @tanstack/angular-db adapter was missing the singleResult handling that was already implemented in react-db and vue-db. The data signal always returned an array (Array.from(currentCollection.values())), regardless of whether findOne() was used. The types also always declared data as Signal<Array<TResult>>.

Fix: Added a computed signal that checks collection.config.singleResult and returns either the first element (for findOne()) or the full array. Updated the type overloads to use InferResultType<TContext>, which correctly resolves to T | undefined for findOne() queries.

• Repro PR (failing test): [repro] findOne returns array instead of single object in angular-db (issue #1261) #1272
• Fix PR: [fix] findOne returns array instead of single object in angular-db (issue #1261) #1273