feat: added schemas, ability to extend json response

Author: monokkai

src/core/generator.ts

@@ -1,10 +1,29 @@
 import type { MockmateOptions } from "./types.js";
 import { fetchData } from "./fetcher.js";
+import { generateFromSchema } from "./shema.js";
 
 export async function generate(options: MockmateOptions) {
-  const data = await fetchData(options.category);
+  let result: any[] = [];
 
-  let result = options.quantity ? data.slice(0, options.quantity) : data;
+  if (options.schema) {
+    result = generateFromSchema(
+      options.schema,
+      options.quantity ?? 1
+    );
+  }
+
+  else if (options.category) {
+    const data = await fetchData(options.category);
+    result = options.quantity
+      ? data.slice(0, options.quantity)
+      : data;
+  }
+
+  else {
+    throw new Error(
+      'Mockmate: provide either "schema" or "category"'
+    );
+  }
 
   if (options.pick) {
     result = result.map((item: Record<string, unknown>) => {
@@ -22,7 +41,10 @@ export async function generate(options: MockmateOptions) {
     result = result.map((item: Record<string, unknown>) => ({
       ...item,
       ...Object.fromEntries(
-        Object.entries(options.extend!).map(([key, fn]) => [key, fn()])
+        Object.entries(options.extend!).map(([key, fn]) => [
+          key,
+          fn(),
+        ])
       ),
     }));
   }

src/core/shema.ts

@@ -0,0 +1,17 @@
+import type { SchemaDefenititon } from "./types";
+
+export function generateFromSchema(schema: SchemaDefenititon, quantity: number = 1) {
+    const result = [];
+
+    for (let i = 0; i < quantity; i++) {
+        const item: Record<string, unknown> = {};
+
+        for (const key in schema) {
+            item[key] = schema[key]();
+        }
+
+        result.push(item)
+    }
+
+    return result;
+}

src/core/types.ts

@@ -2,9 +2,14 @@ export type DataCategory = "users" | "posts" | "comments" | "todos";
 
 export type ExtendFn = () => unknown;
 
+export type GeneratorFn<T = unknown> = () => T;
+
+export type SchemaDefenititon = Record<string, GeneratorFn>;
+
 export interface MockmateOptions {
   category: DataCategory;
   quantity?: number;
   pick?: string[];
   extend?: Record<string, ExtendFn>;
+  schema?: SchemaDefenititon;
 }

src/examples/generate.users.ts

@@ -2,8 +2,11 @@ import { mockmate } from "../index.js";
 
 async function run() {
     const users = await mockmate({
-        category: "posts",
+        category: "users",
         quantity: 2,
+        extend: {
+            zipcode: () => "90566 - 7771"
+        },
     });
 
     console.groupCollapsed("Generated users: ");