Add support for json5 format

Author: typicode

README.md

@@ -12,6 +12,9 @@ npm install json-server
 
 Create a `db.json` file or run `json-server db.json` to create one with some default resources
 
+> [!TIP]
+> You can also use [json5](https://json5.org/) format by creating a `db.json5` instead
+
 ```json
 {
   "posts": [
@@ -27,6 +30,11 @@ Create a `db.json` file or run `json-server db.json` to create one with some def
 
 ```shell
 json-server db.json
+curl -H "Accept: application/json" -X GET http://localhost:3000/posts/1
+{
+  "id": "1",
+  "title": "a title"
+}
 ```
 
 Run `json-server --help` for a list of options

fixtures/db.json5

@@ -0,0 +1,24 @@
+{
+  posts: [
+    {
+      id: '1',
+      title: 'a title',
+    },
+    {
+      id: '2',
+      title: 'another title',
+    },
+  ],
+  comments: [
+    {
+      id: '1',
+      text: 'a comment about post 1',
+      postId: '1',
+    },
+    {
+      id: '2',
+      text: 'another comment about post 1',
+      postId: '1',
+    },
+  ],
+}

package-lock.json

@@ -43,6 +43,7 @@
     "dot-prop": "^8.0.2",
     "eta": "^3.1.1",
     "inflection": "^3.0.0",
+    "json5": "^2.2.3",
     "lowdb": "^6.1.1",
     "milliparsec": "^2.3.0",
     "sirv": "^2.0.3",

package.json

@@ -0,0 +1,25 @@
+import { PathLike } from 'fs'
+import JSON5 from 'json5'
+import { Adapter } from 'lowdb'
+import { TextFile } from 'lowdb/node'
+
+export class JSON5File<T> implements Adapter<T> {
+  #adapter: TextFile
+
+  constructor(filename: PathLike) {
+    this.#adapter = new TextFile(filename)
+  }
+
+  async read(): Promise<T | null> {
+    const data = await this.#adapter.read()
+    if (data === null) {
+      return null
+    } else {
+      return JSON5.parse(data)
+    }
+  }
+
+  write(obj: T): Promise<void> {
+    return this.#adapter.write(JSON5.stringify(obj, null, 2))
+  }
+}

src/JSON5File.ts

@@ -1,6 +1,6 @@
 #!/usr/bin/env node
 import { readFileSync } from 'node:fs'
-import { join } from 'node:path'
+import { extname, join } from 'node:path'
 import { parseArgs } from 'node:util'
 
 import { watch } from 'chokidar'
@@ -9,7 +9,8 @@ import { JSONFile } from 'lowdb/node'
 import { PackageJson } from 'type-fest'
 
 import { createApp } from './app.js'
-import { Observer } from './observer.js'
+import { JSON5File } from './JSON5File.js'
+import { Observer } from './Observer.js'
 import { Data } from './service.js'
 
 // Parse args
@@ -63,7 +64,12 @@ const port = parseInt(values.port ?? process.env['PORT'] ?? '3000')
 const host = values.host ?? process.env['HOST'] ?? 'localhost'
 
 // Set up database
-const adapter = new JSONFile<Data>(file)
+let adapter: JSONFile<Data> | JSON5File<Data>
+if (extname(file) === '.json5') {
+  adapter = new JSON5File<Data>(file)
+} else {
+  adapter = new JSONFile<Data>(file)
+}
 const observer = new Observer(adapter)
 
 const db = new Low<Data>(observer, {})