From a4dda8ec64dcf0c3572db190d03caab191a3f5cc Mon Sep 17 00:00:00 2001
From: typicode <typicode@gmail.com>
Date: Fri, 12 Jan 2024 01:09:16 +0100
Subject: [PATCH] fix: _embed param

---
 src/app.test.ts |  4 ++++
 src/service.ts  | 28 ++++++++++++++++++++--------
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/src/app.test.ts b/src/app.test.ts
index 0cb798957..a40fab6c3 100644
--- a/src/app.test.ts
+++ b/src/app.test.ts
@@ -54,8 +54,10 @@ await new Promise<void>((resolve, reject) => {
 await test('createApp', async (t) => {
   // URLs
   const POSTS = '/posts'
+  const POSTS_WITH_COMMENTS = '/posts?_embed=comments'
   const POST_1 = '/posts/1'
   const POST_NOT_FOUND = '/posts/-1'
+  const POST_WITH_COMMENTS = '/posts/1?_embed=comments'
   const COMMENTS = '/comments'
   const POST_COMMENTS = '/comments?postId=1'
   const NOT_FOUND = '/not-found'
@@ -73,8 +75,10 @@ await test('createApp', async (t) => {
 
     // API
     { method: 'GET', url: POSTS, statusCode: 200 },
+    { method: 'GET', url: POSTS_WITH_COMMENTS, statusCode: 200 },
     { method: 'GET', url: POST_1, statusCode: 200 },
     { method: 'GET', url: POST_NOT_FOUND, statusCode: 404 },
+    { method: 'GET', url: POST_WITH_COMMENTS, statusCode: 200 },
     { method: 'GET', url: COMMENTS, statusCode: 200 },
     { method: 'GET', url: POST_COMMENTS, statusCode: 200 },
     { method: 'GET', url: OBJECT, statusCode: 200 },
diff --git a/src/service.ts b/src/service.ts
index 2e0d597ce..bcf4c1184 100644
--- a/src/service.ts
+++ b/src/service.ts
@@ -47,6 +47,10 @@ export type PaginatedItems = {
   data: Item[]
 }
 
+function ensureArray(arg: string | string[] = []): string[] {
+  return Array.isArray(arg) ? arg : [arg]
+}
+
 function embed(db: Low<Data>, name: string, item: Item, related: string): Item {
   if (inflection.singularize(related) === related) {
     const relatedData = db.data[inflection.pluralize(related)] as Item[]
@@ -148,13 +152,13 @@ export class Service {
   findById(
     name: string,
     id: string,
-    query: { _embed?: string[] },
+    query: { _embed?: string[] | string },
   ): Item | undefined {
     const value = this.#get(name)
 
     if (Array.isArray(value)) {
       let item = value.find((item) => item['id'] === id)
-      query._embed?.forEach((related) => {
+      ensureArray(query._embed).forEach((related) => {
         if (item !== undefined) item = embed(this.#db, name, item, related)
       })
       return item
@@ -184,9 +188,10 @@ export class Service {
     }
 
     // Include
-    query._embed?.forEach((related) => {
-      if (items !== undefined && Array.isArray(items))
+    ensureArray(query._embed).forEach((related) => {
+      if (items !== undefined && Array.isArray(items)) {
         items = items.map((item) => embed(this.#db, name, item, related))
+      }
     })
 
     // Return list if no query params
@@ -209,11 +214,18 @@ export class Service {
         continue
       }
       if (
-        ['_sort', '_start', '_end', '_limit', '_page', '_per_page'].includes(
-          key,
-        )
-      )
+        [
+          '_embed',
+          '_sort',
+          '_start',
+          '_end',
+          '_limit',
+          '_page',
+          '_per_page',
+        ].includes(key)
+      ) {
         continue
+      }
       conds[key] = [Condition.default, value]
     }