Clone the preloader when cloning the query builder

src/orm/preloader/index.ts

@@ -145,6 +145,19 @@ export class Preloader implements PreloaderContract<LucidRow> {
     return this
   }
 
+  /**
+   * Clone preloader instance
+   */
+  clone() {
+    const clone = new Preloader(this.model)
+
+    clone.preloads = Object.assign({}, this.preloads)
+    clone.sideloaded = Object.assign({}, this.sideloaded)
+    clone.debugQueries = this.debugQueries
+
+    return clone
+  }
+
   /**
    * Process of all the preloaded relationships for a single parent
    */

src/orm/query_builder/index.ts

@@ -357,6 +357,7 @@ export class ModelQueryBuilder
     const clonedQuery = new ModelQueryBuilder(this.knexQuery.clone(), this.model, this.client)
     this.applyQueryFlags(clonedQuery)
 
+    clonedQuery.usePreloader(this.preloader.clone())
     clonedQuery.sideloaded = Object.assign({}, this.sideloaded)
     clonedQuery.debug(this.debugQueries)
     clonedQuery.reporterData(this.customReporterData)

src/types/relations.ts

@@ -1070,4 +1070,5 @@ export interface PreloaderContract<Model extends LucidRow> {
 
   debug(debug: boolean): this
   sideload(values: ModelObject): this
+  clone(): PreloaderContract<Model>
 }

test/orm/model_query_builder.spec.ts

@@ -21,7 +21,7 @@ import {
   resetTables,
   getBaseModel,
 } from '../../test-helpers/index.js'
-import { HasMany } from '../../src/types/relations.js'
+import type { HasMany } from '../../src/types/relations.js'
 
 test.group('Model query builder', (group) => {
   group.setup(async () => {
@@ -346,6 +346,93 @@ test.group('Model query builder', (group) => {
     assert.deepEqual(user.$sideloaded, { username: 'virk' })
   })
 
+  test('clone query builder with preload', async ({ fs, assert }) => {
+    const app = new AppFactory().create(fs.baseUrl, () => {})
+    await app.init()
+    const db = getDb()
+    const adapter = ormAdapter(db)
+    const BaseModel = getBaseModel(adapter)
+
+    class Post extends BaseModel {
+      @column()
+      declare id: number
+
+      @column()
+      declare userId: number
+
+      @column()
+      declare title: string
+    }
+    Post.boot()
+
+    class User extends BaseModel {
+      @column({ isPrimary: true })
+      declare id: number
+
+      @column()
+      declare username: string
+
+      @hasMany(() => Post)
+      declare posts: HasMany<typeof Post>
+    }
+    User.boot()
+
+    const user = await User.create({ username: 'virk' })
+    const posts = await user
+      .related('posts')
+      .createMany([{ title: 'Adonis 101' }, { title: 'Lucid 101' }])
+
+    const query = User.query().preload('posts')
+    const clone = await query.clone().firstOrFail()
+    assert.isArray(clone.posts)
+    assert.equal(clone.posts.length, posts.length)
+  })
+
+  test('clone query builder with preload', async ({ fs, assert }) => {
+    const app = new AppFactory().create(fs.baseUrl, () => {})
+    await app.init()
+    const db = getDb()
+    const adapter = ormAdapter(db)
+    const BaseModel = getBaseModel(adapter)
+
+    class Post extends BaseModel {
+      @column()
+      declare id: number
+
+      @column()
+      declare userId: number
+
+      @column()
+      declare title: string
+    }
+    Post.boot()
+
+    class User extends BaseModel {
+      @column({ isPrimary: true })
+      declare id: number
+
+      @column()
+      declare username: string
+
+      @hasMany(() => Post)
+      declare posts: HasMany<typeof Post>
+    }
+    User.boot()
+
+    const user = await User.create({ username: 'virk' })
+    await user.related('posts').createMany([{ title: 'Adonis 101' }, { title: 'Lucid 101' }])
+
+    const query = User.query()
+    const queryCloned = query.clone()
+
+    query.preload('posts')
+    const clone = await queryCloned.firstOrFail()
+    const users = await query.firstOrFail()
+
+    assert.isUndefined(clone.posts)
+    assert.lengthOf(users.posts, 2)
+  })
+
   test('apply scopes', async ({ fs, assert }) => {
     const app = new AppFactory().create(fs.baseUrl, () => {})
     await app.init()