refactor: do not have defaults for relationships, let the end user de…

…fine them

src/Orm/BaseModel/index.ts

@@ -703,19 +703,15 @@ export class BaseModel implements ModelContract {
   /**
    * Returns the related model or default value when model is missing
    */
-  public $getRelated (key: string, defaultValue: any): any {
-    if (this.$hasRelated(key)) {
-      return this.$preloaded[key as string]
-    }
-
-    return defaultValue
+  public $getRelated (key: string): any {
+    return this.$preloaded[key]
   }
 
   /**
    * A boolean to know if relationship has been preloaded or not
    */
   public $hasRelated (key: string): boolean {
-    return this.$preloaded[key as string] !== undefined
+    return this.$preloaded[key] !== undefined
   }
 
   /**
@@ -739,13 +735,13 @@ export class BaseModel implements ModelContract {
     const manyRelationships = ['hasMany', 'manyToMany', 'hasManyThrough']
     if (manyRelationships.includes(relation.type)) {
       if (!Array.isArray(models)) {
-        throw new Exception(`
-          $setRelated accepts an array of related models for ${manyRelationships.join(',')} relationships,
-        `)
+        throw new Exception(
+          `${Model}.${key} must be an array (${manyRelationships.join(',')} relationships)`,
+        )
       }
-      this.$preloaded[key as string] = models
+      this.$preloaded[key] = models
     } else {
-      this.$preloaded[key as string] = models as unknown as ModelContract
+      this.$preloaded[key] = models as unknown as ModelContract
     }
   }
 

src/Orm/BaseModel/proxyHandler.ts

@@ -9,30 +9,7 @@
 
 /// <reference path="../../../adonis-typings/index.ts" />
 
-import { Exception } from '@poppinss/utils'
-import { ModelConstructorContract, AvailableRelations } from '@ioc:Adonis/Lucid/Model'
-
-/**
- * Value to return when relationship is not preloaded
- * with the model instance.
- *
- * We are re-using the defaults from a static source to avoid creating empty arrays
- * everytime someone access the relationship. However, as a downside, if someone
- * decides to mutate the array, that will mutate the source and hence we
- * freeze the arrays.
- *
- * The `Object.freeze` however doesn't stop one from defining values for a specific
- * index.
- */
-const DEFAULTS: {
-  [P in AvailableRelations]: any
-} = {
-  hasOne: null,
-  hasMany: Object.freeze([]),
-  belongsTo: null,
-  manyToMany: Object.freeze([]),
-  hasManyThrough: Object.freeze([]),
-}
+import { ModelConstructorContract } from '@ioc:Adonis/Lucid/Model'
 
 /**
  * A proxy trap to add support for custom getters and setters
@@ -55,7 +32,7 @@ export const proxyHandler = {
      */
     const relation = Model.$getRelation(key)
     if (relation) {
-      return target.$getRelated(key, DEFAULTS[relation.type])
+      return target.$getRelated(key)
     }
 
     return Reflect.get(target, key, receiver)
@@ -79,7 +56,8 @@ export const proxyHandler = {
      */
     const relation = Model.$getRelation(key)
     if (relation) {
-      throw new Exception('Cannot set relationships locally', 500, 'E_CANNOT_DEFINE_RELATIONSHIP')
+      target.$setRelated(key, value)
+      return true
     }
 
     return Reflect.set(target, key, value, receiver)

test/orm/base-model.spec.ts

@@ -1114,7 +1114,7 @@ test.group('Base Model | relations', (group) => {
     assert.instanceOf(user.$preloaded.profile, Profile)
   })
 
-  test('return null when relation is not preloaded', (assert) => {
+  test('return undefined when relation is not preloaded', (assert) => {
     class Profile extends BaseModel {
       @column()
       public username: string
@@ -1136,7 +1136,7 @@ test.group('Base Model | relations', (group) => {
       id: 1,
     })
 
-    assert.isNull(user.profile)
+    assert.isUndefined(user.profile)
     assert.deepEqual(user.$preloaded, {})
   })
 

test/orm/model-belongs-to.spec.ts

@@ -476,7 +476,7 @@ test.group('Model | BelongsTo', (group) => {
       builder.whereNull('username')
     }).first()
 
-    assert.isNull(profile!.user)
+    assert.isUndefined(profile!.user)
   })
 
   test('preload nested relations', async (assert) => {

test/orm/model-has-one.spec.ts

@@ -446,7 +446,7 @@ test.group('Model | HasOne | preload', (group) => {
       builder.whereNull('display_name')
     }).where('username', 'virk').first()
 
-    assert.isNull(user!.profile)
+    assert.isUndefined(user!.profile)
   })
 
   test('preload nested relations', async (assert) => {