fix(belongsToMany): pivotModel should allow class and ioc container s…

…tring

closes #254

src/Lucid/Relations/BelongsToMany.js

@@ -18,6 +18,7 @@
 
 const _ = require('lodash')
 const GE = require('@adonisjs/generic-exceptions')
+const { ioc } = require('../../../lib/iocResolver')
 
 const BaseRelation = require('./BaseRelation')
 const util = require('../../../lib/util')
@@ -422,7 +423,7 @@ class BelongsToMany extends BaseRelation {
    * @chainable
    */
   pivotModel (pivotModel) {
-    this._PivotModel = pivotModel
+    this._PivotModel = typeof (pivotModel) === 'string' ? ioc.use(pivotModel) : pivotModel
     return this
   }
 

test/unit/lucid-belongs-to-many.spec.js

@@ -2004,4 +2004,28 @@ test.group('Relations | Belongs To Many', (group) => {
     assert.equal(pivotValues[0].user_id, 1)
     assert.equal(pivotValues[0].post_id, 2)
   })
+
+  test('define pivot model via ioc container string', (assert) => {
+    class Post extends Model {
+    }
+
+    ioc.fake('App/Models/PostUser', () => {
+      class PostUser extends Model {
+      }
+      return PostUser
+    })
+
+    class User extends Model {
+      posts () {
+        return this.belongsToMany(Post).pivotModel('App/Models/PostUser')
+      }
+    }
+
+    User._bootIfNotBooted()
+    Post._bootIfNotBooted()
+
+    const user = new User()
+    const userPosts = user.posts()
+    assert.equal(userPosts.$pivotTable, 'post_users')
+  })
 })