fix: properly handle polymorphic relationships

atoms-studio · Feb 1, 2022 · 39f6bd3 · 39f6bd3
1 parent bee94d8
commit 39f6bd3
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Showing 3 changed files with 94 additions and 4 deletions.
diff --git a/__tests__/serializer.spec.ts b/__tests__/serializer.spec.ts
@@ -85,6 +85,75 @@ describe('serializer', () => {
     })
   })
 
+  it('serializes a resource with polymorphic relations', async () => {
+    await expect(async () => {
+      await serialize(
+        {
+          type: 'line_items',
+
+          attributes: ['quantity'],
+
+          relationships: {
+            order: 'orders',
+            item: {
+              polymorphic: true,
+              field: 'item_type',
+            },
+            line_item_options: 'line_item_options',
+            shipment_line_items: 'line_items',
+            stock_transfers: 'stock_transfers',
+          },
+        },
+        {
+          quantity: 1,
+        },
+        {
+          order: {
+            id: '12345',
+            type: 'orders',
+          },
+          item: '123456',
+        },
+      )
+    }).rejects.toThrow(
+      'You must pass a type for relationship "item" because it is polymorphic',
+    )
+
+    const body = await serialize(
+      {
+        type: 'line_items',
+
+        attributes: ['quantity'],
+
+        relationships: {
+          order: 'orders',
+          item: {
+            polymorphic: true,
+            field: 'item_type',
+          },
+          line_item_options: 'line_item_options',
+          shipment_line_items: 'line_items',
+          stock_transfers: 'stock_transfers',
+        },
+      },
+      {
+        quantity: 1,
+      },
+      {
+        order: {
+          id: '12345',
+          type: 'orders',
+        },
+        item: {
+          id: '123456',
+          type: 'adjustments',
+        },
+      },
+    )
+
+    expect(body.data.relationships.item.data.type).toEqual('adjustments')
+  })
+
   it('throws an error with invalid attributes', async () => {
     await expect(async () => {
       await serialize(

diff --git a/src/resource.ts b/src/resource.ts
@@ -10,10 +10,15 @@ import {
 } from './api'
 import { getType, isObject } from './utils'
 
+export interface PolymorphicRelationship {
+  polymorphic: true
+  field: string
+}
+
 export interface ResourceConfig<T, U> {
   type: string
   attributes: (keyof T)[]
-  relationships: Record<keyof U, string>
+  relationships: Record<keyof U, string | PolymorphicRelationship>
 }
 
 export interface CommonResourceAttributes {

diff --git a/src/serializer.ts b/src/serializer.ts
@@ -4,6 +4,7 @@ import {
   ResourceConfig,
   AttributesPayload,
   RelationshipsPayload,
+  PolymorphicRelationship,
 } from './resource'
 import { getType, isObject } from './utils'
 
@@ -84,10 +85,15 @@ export const serialize = async <T, U>(
     //
     relationshipKeys.forEach((relationshipKey) => {
       // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      const configRelationships: Record<string, any> = config.relationships
+      const configRelationships: Record<
+        string,
+        string | PolymorphicRelationship
+      > = config.relationships
+
+      const relationshipTypeConfig = configRelationships[relationshipKey]
 
       // Only add relationships supported by the config
-      if (configRelationships[relationshipKey]) {
+      if (relationshipTypeConfig) {
         // eslint-disable-next-line @typescript-eslint/no-explicit-any
         const relationshipValue = (relationships as any)[relationshipKey] || {
           id: null,
@@ -99,9 +105,19 @@ export const serialize = async <T, U>(
           )
         }
 
+        if (
+          typeof relationshipTypeConfig === 'object' &&
+          relationshipTypeConfig.polymorphic &&
+          (typeof relationshipValue === 'string' || !relationshipValue.type)
+        ) {
+          throw new Error(
+            `You must pass a type for relationship "${relationshipKey}" because it is polymorphic`,
+          )
+        }
+
         serialized.data.relationships[relationshipKey] = {
           data: {
-            type: configRelationships[relationshipKey],
+            type: relationshipValue.type ?? relationshipTypeConfig,
             // Support passing a relationship as id or as a full object
             id:
               typeof relationshipValue === 'string'