feat: pass in index to FactoryValueGenerator

README.md

@@ -181,10 +181,18 @@ With the scripts integrated in the `package.json` file, now you could run 2 diff
 ```typescript
 @Schema()
 export class User extends Document {
+  // Generates a consistent UUID based on the index of the generated data.
+  // Useful during development when you want to have a consistent ID.
+  @Factory((_, __, index) => uuidv5(index.toString(), this.name))
+  @Prop({ required: true })
+  id: string;
+
   @Factory((faker) => faker.helpers.arrayElement(["male", "female"]))
   @Prop({ required: true })
   gender: string;
 
+  // Using the context, you could access the previously generated value.
+  // generates a first name based on the gender.
   @Factory((faker, ctx) => faker.person.firstName(ctx.gender))
   @Prop({ required: true })
   firstName: string;

lib/decorators/factory.decorator.ts

@@ -1,9 +1,14 @@
-import { FactoryMetadataStorage } from '../storages/factory.metadata.storage';
-import { Faker } from '@faker-js/faker';
+import { FactoryMetadataStorage } from "../storages/factory.metadata.storage";
+import { Faker } from "@faker-js/faker";
 
 type BaseType = string | number | Date | Buffer | boolean | Record<string, any>;
 export type FactoryValue = BaseType | Array<BaseType>;
-export type FactoryValueGenerator = (faker?: Faker, ctx?: Record<string, any>) => FactoryValue;
+export type FactoryValueGenerator = (
+  faker?: Faker,
+  ctx?: Record<string, any>,
+  // @ts-ignore - Added to support the index parameter with backwards compatibility
+  index: number
+) => FactoryValue;
 
 export function Factory(arg: FactoryValueGenerator | FactoryValue) {
   return (target: Record<string, any>, propertyKey: string | symbol): void => {

lib/factory/data.factory.ts

@@ -1,8 +1,8 @@
-import { Type } from '@nestjs/common';
-import { Factory, PropertyMetadata } from '../interfaces';
-import { FactoryValue } from '../decorators/factory.decorator';
-import { FactoryMetadataStorage } from '../storages/factory.metadata.storage';
-import { faker } from '@faker-js/faker';
+import { Type } from "@nestjs/common";
+import { Factory, PropertyMetadata } from "../interfaces";
+import { FactoryValue } from "../decorators/factory.decorator";
+import { FactoryMetadataStorage } from "../storages/factory.metadata.storage";
+import { faker } from "@faker-js/faker";
 
 export class DataFactory {
   static createForClass(target: Type<unknown>): Factory {
@@ -16,7 +16,10 @@ export class DataFactory {
       FactoryMetadataStorage.getPropertyMetadatasByTarget(target);
 
     return {
-      generate: (count: number, values: Record<string, any> = {}): Record<string, FactoryValue>[] => {
+      generate: (
+        count: number,
+        values: Record<string, any> = {}
+      ): Record<string, FactoryValue>[] => {
         const ret = Array<Record<string, FactoryValue>>();
         for (let i = 0; i < count; i++) {
           ret.push(this.generate(properties, values));
@@ -28,12 +31,13 @@ export class DataFactory {
 
   private static generate(
     properties: PropertyMetadata[],
-    values: Record<string, any>,
+    values: Record<string, any>
   ): Record<string, FactoryValue> {
     const ctx = { ...values };
     return properties.reduce(
-      (r, p) => ({
-        [p.propertyKey]: ctx[p.propertyKey] = typeof p.arg === 'function' ? p.arg(faker, ctx) : p.arg,
+      (r, p, index) => ({
+        [p.propertyKey]: (ctx[p.propertyKey] =
+          typeof p.arg === "function" ? p.arg(faker, ctx, index) : p.arg),
         ...r,
       }),
       {}

sample/src/schemas/user.schema.ts

@@ -38,7 +38,7 @@ export class User extends Document {
 
   // If you pass predefined values to the `generate` function, you will be
   // able to access it in the context.
-  @Factory((faker, ctx) => `${faker.location.streetAddress()} ${ctx.zipCode}`)
+  @Factory((faker, ctx, index) => `${faker.location.streetAddress()} ${ctx.zipCode} ${index}`)
   @Prop({ required: true })
   address: string;
 }