From 24a25bace8374de4f2255b8a248ad0d53c0726c8 Mon Sep 17 00:00:00 2001
From: ST-DDT <ST-DDT@gmx.de>
Date: Sat, 20 Apr 2024 15:50:50 +0200
Subject: [PATCH 01/11] feat: introduce FakerCore

---
 package.json                |  5 ---
 src/config.ts               | 20 ++++++++++++
 src/core.ts                 | 25 +++++++++++++++
 src/faker.ts                | 61 ++++++++++++++++++++++++-------------
 src/modules/number/index.ts |  6 ++--
 src/simple-faker.ts         | 48 ++++++++++++++++++-----------
 test/all-functional.spec.ts |  8 +----
 test/modules/number.spec.ts |  3 +-
 8 files changed, 120 insertions(+), 56 deletions(-)
 create mode 100644 src/config.ts
 create mode 100644 src/core.ts

diff --git a/package.json b/package.json
index 782f5f8f8f4..0f1b1cedb51 100644
--- a/package.json
+++ b/package.json
@@ -134,10 +134,5 @@
     "vitepress": "1.1.0",
     "vitest": "1.5.0",
     "vue": "3.4.21"
-  },
-  "packageManager": "pnpm@9.0.1",
-  "engines": {
-    "node": ">=18.0.0",
-    "npm": ">=9.0.0"
   }
 }
diff --git a/src/config.ts b/src/config.ts
new file mode 100644
index 00000000000..991dda70e6b
--- /dev/null
+++ b/src/config.ts
@@ -0,0 +1,20 @@
+/**
+ * The possible configuration options, that can be set.
+ * This type exists to be extended for plugins via type augmentation.
+ *
+ * The `@default` tag is used to indicate the default value, that should be used if, the config is absent.
+ */
+export interface FakerConfig {
+  /**
+   * The function used to generate the `refDate` date instance, if not provided as method param.
+   * The function must return a new valid `Date` instance for every call.
+   *
+   * @see [Reproducible Results](https://fakerjs.dev/guide/usage.html#reproducible-results)
+   * @see faker.seed(): For generating reproducible values.
+   *
+   * @since 9.0.0
+   *
+   * @default () => new Date()
+   */
+  refDate?: () => Date;
+}
diff --git a/src/core.ts b/src/core.ts
new file mode 100644
index 00000000000..3609fd65f0a
--- /dev/null
+++ b/src/core.ts
@@ -0,0 +1,25 @@
+import type { FakerConfig } from './config';
+import type { LocaleDefinition } from './definitions';
+import type { Randomizer } from './randomizer';
+
+/**
+ * The core grants access to the locale data, the randomizer and config settings.
+ */
+export interface FakerCore {
+  /**
+   * The locale data associated with this instance.
+   *
+   * Always present, but it might be empty if the locale data is not available.
+   */
+  readonly locale: LocaleDefinition;
+
+  /**
+   * The randomizer used to generate random values.
+   */
+  readonly randomizer: Randomizer;
+
+  /**
+   * The configuration settings used by this instance.
+   */
+  readonly config: FakerConfig;
+}
diff --git a/src/faker.ts b/src/faker.ts
index 5f5e14ce392..b5987d41fe8 100644
--- a/src/faker.ts
+++ b/src/faker.ts
@@ -1,6 +1,8 @@
+import type { FakerCore } from './core';
 import type { LocaleDefinition, MetadataDefinition } from './definitions';
 import { FakerError } from './errors/faker-error';
 import { deprecated } from './internal/deprecated';
+import { generateMersenne53Randomizer } from './internal/mersenne';
 import type { LocaleProxy } from './locale-proxy';
 import { createLocaleProxy } from './locale-proxy';
 import { AirlineModule } from './modules/airline';
@@ -58,7 +60,6 @@ import { mergeLocales } from './utils/merge-locales';
  * customFaker.music.genre(); // throws Error as this data is not available in `es`
  */
 export class Faker extends SimpleFaker {
-  readonly rawDefinitions: LocaleDefinition;
   readonly definitions: LocaleProxy;
 
   readonly airline: AirlineModule = new AirlineModule(this);
@@ -85,6 +86,10 @@ export class Faker extends SimpleFaker {
   readonly vehicle: VehicleModule = new VehicleModule(this);
   readonly word: WordModule = new WordModule(this);
 
+  get rawDefinitions(): LocaleDefinition {
+    return this.fakerCore.locale;
+  }
+
   // Aliases
   /** @deprecated Use {@link Faker#location} instead */
   get address(): AddressModule {
@@ -138,27 +143,40 @@ export class Faker extends SimpleFaker {
    *
    * @since 8.0.0
    */
-  constructor(options: {
-    /**
-     * The locale data to use for this instance.
-     * If an array is provided, the first locale that has a definition for a given property will be used.
-     *
-     * @see mergeLocales(): For more information about how the locales are merged.
-     */
-    locale: LocaleDefinition | LocaleDefinition[];
+  constructor(
+    options:
+      | {
+          /**
+           * The locale data to use for this instance.
+           * If an array is provided, the first locale that has a definition for a given property will be used.
+           *
+           * @see mergeLocales(): For more information about how the locales are merged.
+           */
+          locale: LocaleDefinition | LocaleDefinition[];
 
-    /**
-     * The Randomizer to use.
-     * Specify this only if you want to use it to achieve a specific goal,
-     * such as sharing the same random generator with other instances/tools.
-     *
-     * @default generateMersenne53Randomizer()
-     */
+          /**
+           * The Randomizer to use.
+           * Specify this only if you want to use it to achieve a specific goal,
+           * such as sharing the same random generator with other instances/tools.
+           *
+           * @default generateMersenne53Randomizer()
+           */
+          randomizer?: Randomizer;
+        }
+      | {
+          /**
+           * The faker core with the randomizer, locale data and config to use.
+           */
+          fakerCore: FakerCore;
+        }
+  );
+  constructor(options: {
+    locale?: LocaleDefinition | LocaleDefinition[];
     randomizer?: Randomizer;
+    fakerCore?: FakerCore;
   }) {
-    super({ randomizer: options.randomizer });
-
-    let { locale } = options;
+    const { randomizer = generateMersenne53Randomizer(), fakerCore } = options;
+    let { locale = {} } = options;
 
     if (Array.isArray(locale)) {
       if (locale.length === 0) {
@@ -170,7 +188,8 @@ export class Faker extends SimpleFaker {
       locale = mergeLocales(locale);
     }
 
-    this.rawDefinitions = locale;
+    super({ fakerCore: fakerCore ?? { locale, randomizer, config: {} } });
+
     this.definitions = createLocaleProxy(this.rawDefinitions);
   }
 
@@ -186,7 +205,7 @@ export class Faker extends SimpleFaker {
    * @since 8.1.0
    */
   getMetadata(): MetadataDefinition {
-    return this.rawDefinitions.metadata ?? {};
+    return this.fakerCore.locale.metadata ?? {};
   }
 }
 
diff --git a/src/modules/number/index.ts b/src/modules/number/index.ts
index be5e213f272..621b0adc78a 100644
--- a/src/modules/number/index.ts
+++ b/src/modules/number/index.ts
@@ -96,8 +96,7 @@ export class NumberModule extends SimpleModuleBase {
       throw new FakerError(`Max ${max} should be greater than min ${min}.`);
     }
 
-    // @ts-expect-error: access private member field
-    const randomizer = this.faker._randomizer;
+    const { randomizer } = this.faker.fakerCore;
     const real = randomizer.next();
     const delta = effectiveMax - effectiveMin + 1; // +1 for inclusive max bounds and even distribution
     return Math.floor(real * delta + effectiveMin) * multipleOf;
@@ -214,8 +213,7 @@ export class NumberModule extends SimpleModuleBase {
       return int / factor;
     }
 
-    // @ts-expect-error: access private member field
-    const randomizer = this.faker._randomizer;
+    const { randomizer } = this.faker.fakerCore;
     const real = randomizer.next();
     return real * (max - min) + min;
   }
diff --git a/src/simple-faker.ts b/src/simple-faker.ts
index e775cbc7b5d..11bce1bd9d0 100644
--- a/src/simple-faker.ts
+++ b/src/simple-faker.ts
@@ -1,3 +1,4 @@
+import type { FakerCore } from './core';
 import { generateMersenne53Randomizer } from './internal/mersenne';
 import { DatatypeModule } from './modules/datatype';
 import { SimpleDateModule } from './modules/date';
@@ -26,13 +27,13 @@ import type { Randomizer } from './randomizer';
  * simpleFaker.string.uuid(); // 'c50e1f5c-86e8-4aa9-888e-168e0a182519'
  */
 export class SimpleFaker {
-  protected _defaultRefDate: () => Date = () => new Date();
+  readonly fakerCore: FakerCore;
 
   /**
    * Gets a new reference date used to generate relative dates.
    */
   get defaultRefDate(): () => Date {
-    return this._defaultRefDate;
+    return this.fakerCore.config.refDate ?? (() => new Date());
   }
 
   /**
@@ -72,15 +73,12 @@ export class SimpleFaker {
     dateOrSource: string | Date | number | (() => Date) = () => new Date()
   ): void {
     if (typeof dateOrSource === 'function') {
-      this._defaultRefDate = dateOrSource;
+      this.fakerCore.config.refDate = dateOrSource;
     } else {
-      this._defaultRefDate = () => new Date(dateOrSource);
+      this.fakerCore.config.refDate = () => new Date(dateOrSource);
     }
   }
 
-  /** @internal */
-  private readonly _randomizer: Randomizer;
-
   readonly datatype: DatatypeModule = new DatatypeModule(this);
   readonly date: SimpleDateModule = new SimpleDateModule(this);
   readonly helpers: SimpleHelpersModule = new SimpleHelpersModule(this);
@@ -110,21 +108,37 @@ export class SimpleFaker {
    *
    * @since 8.1.0
    */
+  constructor(
+    options?:
+      | {
+          /**
+           * The Randomizer to use.
+           * Specify this only if you want to use it to achieve a specific goal,
+           * such as sharing the same random generator with other instances/tools.
+           *
+           * @default generateMersenne53Randomizer()
+           */
+          randomizer?: Randomizer;
+        }
+      | {
+          /**
+           * The faker core with the randomizer and config to use.
+           */
+          fakerCore: FakerCore;
+        }
+  );
   constructor(
     options: {
-      /**
-       * The Randomizer to use.
-       * Specify this only if you want to use it to achieve a specific goal,
-       * such as sharing the same random generator with other instances/tools.
-       *
-       * @default generateMersenne53Randomizer()
-       */
       randomizer?: Randomizer;
+      fakerCore?: FakerCore;
     } = {}
   ) {
-    const { randomizer = generateMersenne53Randomizer() } = options;
+    const {
+      randomizer = generateMersenne53Randomizer(),
+      fakerCore = { locale: {}, randomizer, config: {} },
+    } = options;
 
-    this._randomizer = randomizer;
+    this.fakerCore = fakerCore;
   }
 
   /**
@@ -250,7 +264,7 @@ export class SimpleFaker {
   seed(
     seed: number | number[] = Math.ceil(Math.random() * Number.MAX_SAFE_INTEGER)
   ): number | number[] {
-    this._randomizer.seed(seed);
+    this.fakerCore.randomizer.seed(seed);
 
     return seed;
   }
diff --git a/test/all-functional.spec.ts b/test/all-functional.spec.ts
index 12b69ba1fb7..384519cbd5f 100644
--- a/test/all-functional.spec.ts
+++ b/test/all-functional.spec.ts
@@ -3,13 +3,7 @@ import type { Faker, allLocales } from '../src';
 import { allFakers, fakerEN } from '../src';
 import { keys } from '../src/internal/keys';
 
-const IGNORED_MODULES = new Set([
-  'rawDefinitions',
-  'definitions',
-  'helpers',
-  '_randomizer',
-  '_defaultRefDate',
-]);
+const IGNORED_MODULES = new Set(['rawDefinitions', 'helpers', 'fakerCore']);
 
 function getMethodNamesByModules(faker: Faker): { [module: string]: string[] } {
   return Object.fromEntries(
diff --git a/test/modules/number.spec.ts b/test/modules/number.spec.ts
index f318fc5be09..4c45efd6f82 100644
--- a/test/modules/number.spec.ts
+++ b/test/modules/number.spec.ts
@@ -629,8 +629,7 @@ describe('number', () => {
 
   describe('value range tests', () => {
     const customFaker = new SimpleFaker();
-    // @ts-expect-error: access private member field
-    const randomizer = customFaker._randomizer;
+    const { randomizer } = customFaker.fakerCore;
     describe('int', () => {
       it('should be able to return 0', () => {
         randomizer.next = () => 0;

From 1688003780f2e1794eca503c41ce3b13ce94842d Mon Sep 17 00:00:00 2001
From: ST-DDT <ST-DDT@gmx.de>
Date: Sat, 20 Apr 2024 16:13:31 +0200
Subject: [PATCH 02/11] chore: restore

---
 package.json | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/package.json b/package.json
index 0f1b1cedb51..782f5f8f8f4 100644
--- a/package.json
+++ b/package.json
@@ -134,5 +134,10 @@
     "vitepress": "1.1.0",
     "vitest": "1.5.0",
     "vue": "3.4.21"
+  },
+  "packageManager": "pnpm@9.0.1",
+  "engines": {
+    "node": ">=18.0.0",
+    "npm": ">=9.0.0"
   }
 }

From 790e64574e74de3b0a216db445cee1e069e1d61c Mon Sep 17 00:00:00 2001
From: ST-DDT <ST-DDT@gmx.de>
Date: Mon, 22 Apr 2024 23:28:26 +0200
Subject: [PATCH 03/11] chore: apply suggestions

---
 src/config.ts       | 2 +-
 src/faker.ts        | 8 ++++++--
 src/simple-faker.ts | 6 +++---
 3 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/src/config.ts b/src/config.ts
index 991dda70e6b..5b3084290b7 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -16,5 +16,5 @@ export interface FakerConfig {
    *
    * @default () => new Date()
    */
-  refDate?: () => Date;
+  defaultRefDate?: () => Date;
 }
diff --git a/src/faker.ts b/src/faker.ts
index b5987d41fe8..22804100f45 100644
--- a/src/faker.ts
+++ b/src/faker.ts
@@ -175,7 +175,6 @@ export class Faker extends SimpleFaker {
     randomizer?: Randomizer;
     fakerCore?: FakerCore;
   }) {
-    const { randomizer = generateMersenne53Randomizer(), fakerCore } = options;
     let { locale = {} } = options;
 
     if (Array.isArray(locale)) {
@@ -188,7 +187,12 @@ export class Faker extends SimpleFaker {
       locale = mergeLocales(locale);
     }
 
-    super({ fakerCore: fakerCore ?? { locale, randomizer, config: {} } });
+    const {
+      randomizer = generateMersenne53Randomizer(),
+      fakerCore = { locale, randomizer, config: {} },
+    } = options;
+
+    super({ fakerCore });
 
     this.definitions = createLocaleProxy(this.rawDefinitions);
   }
diff --git a/src/simple-faker.ts b/src/simple-faker.ts
index 11bce1bd9d0..80ef3a53076 100644
--- a/src/simple-faker.ts
+++ b/src/simple-faker.ts
@@ -33,7 +33,7 @@ export class SimpleFaker {
    * Gets a new reference date used to generate relative dates.
    */
   get defaultRefDate(): () => Date {
-    return this.fakerCore.config.refDate ?? (() => new Date());
+    return this.fakerCore.config.defaultRefDate ?? (() => new Date());
   }
 
   /**
@@ -73,9 +73,9 @@ export class SimpleFaker {
     dateOrSource: string | Date | number | (() => Date) = () => new Date()
   ): void {
     if (typeof dateOrSource === 'function') {
-      this.fakerCore.config.refDate = dateOrSource;
+      this.fakerCore.config.defaultRefDate = dateOrSource;
     } else {
-      this.fakerCore.config.refDate = () => new Date(dateOrSource);
+      this.fakerCore.config.defaultRefDate = () => new Date(dateOrSource);
     }
   }
 

From 6ef3999308d31990c1aced4658291a2d590dcac1 Mon Sep 17 00:00:00 2001
From: ST-DDT <ST-DDT@gmx.de>
Date: Tue, 14 May 2024 22:36:33 +0200
Subject: [PATCH 04/11] chore: todos

---
 src/faker.ts                | 1 +
 test/all-functional.spec.ts | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/faker.ts b/src/faker.ts
index 22804100f45..fab9d8dfef0 100644
--- a/src/faker.ts
+++ b/src/faker.ts
@@ -87,6 +87,7 @@ export class Faker extends SimpleFaker {
   readonly word: WordModule = new WordModule(this);
 
   get rawDefinitions(): LocaleDefinition {
+    // TODO @ST-DDT 2024-05-14: Should we deprecate this?
     return this.fakerCore.locale;
   }
 
diff --git a/test/all-functional.spec.ts b/test/all-functional.spec.ts
index 384519cbd5f..201cf63010d 100644
--- a/test/all-functional.spec.ts
+++ b/test/all-functional.spec.ts
@@ -3,7 +3,7 @@ import type { Faker, allLocales } from '../src';
 import { allFakers, fakerEN } from '../src';
 import { keys } from '../src/internal/keys';
 
-const IGNORED_MODULES = new Set(['rawDefinitions', 'helpers', 'fakerCore']);
+const IGNORED_MODULES = new Set(['definitions', 'helpers', 'fakerCore']);
 
 function getMethodNamesByModules(faker: Faker): { [module: string]: string[] } {
   return Object.fromEntries(

From 66f46968569d68e101a949cc3639cbfe6e1018f1 Mon Sep 17 00:00:00 2001
From: ST-DDT <ST-DDT@gmx.de>
Date: Tue, 14 May 2024 22:37:59 +0200
Subject: [PATCH 05/11] chore: workaround

---
 src/faker.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/faker.ts b/src/faker.ts
index fab9d8dfef0..abb925f53cb 100644
--- a/src/faker.ts
+++ b/src/faker.ts
@@ -176,6 +176,8 @@ export class Faker extends SimpleFaker {
     randomizer?: Randomizer;
     fakerCore?: FakerCore;
   }) {
+    super(options);
+
     let { locale = {} } = options;
 
     if (Array.isArray(locale)) {
@@ -193,7 +195,10 @@ export class Faker extends SimpleFaker {
       fakerCore = { locale, randomizer, config: {} },
     } = options;
 
-    super({ fakerCore });
+    // TODO @ST-DDT 2024-05-14: Workaround for https://github.com/egoist/tsup/issues/1124
+    // @ts-expect-error: fakerCore is not writable
+    this.fakerCore = fakerCore;
+    // super({ fakerCore });
 
     this.definitions = createLocaleProxy(this.rawDefinitions);
   }

From 6dada60781938d5e76f87062abf0be9d1f9cf7b1 Mon Sep 17 00:00:00 2001
From: ST-DDT <ST-DDT@gmx.de>
Date: Sun, 22 Mar 2026 20:41:17 +0100
Subject: [PATCH 06/11] chore: cleanup imports

---
 test/core.spec.ts | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/test/core.spec.ts b/test/core.spec.ts
index 4db0d78367a..d6bc607f634 100644
--- a/test/core.spec.ts
+++ b/test/core.spec.ts
@@ -1,11 +1,9 @@
 import { describe, expect, it, vi } from 'vitest';
-import {
-  generateMersenne53Randomizer,
-  type LocaleDefinition,
-  type Randomizer,
-} from '../src';
 import type { FakerConfig } from '../src/config';
 import { createFakerCore } from '../src/core';
+import type { LocaleDefinition } from '../src/definitions/definitions';
+import type { Randomizer } from '../src/randomizer';
+import { generateMersenne53Randomizer } from '../src/utils/mersenne';
 
 describe('createFakerCore', () => {
   describe('locale', () => {

From 4f9907a42f6a9f50e0f3243772a225d7561585bc Mon Sep 17 00:00:00 2001
From: ST-DDT <ST-DDT@gmx.de>
Date: Sun, 22 Mar 2026 21:01:22 +0100
Subject: [PATCH 07/11] chore: simplify FakerOptions

---
 src/core.ts         | 4 ++--
 src/faker.ts        | 6 ++----
 src/index.ts        | 2 +-
 src/simple-faker.ts | 4 ++--
 4 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/src/core.ts b/src/core.ts
index b680f8e7ae9..f3c7efd138b 100644
--- a/src/core.ts
+++ b/src/core.ts
@@ -26,7 +26,7 @@ export interface FakerCore {
   readonly config: FakerConfig;
 }
 
-export interface FakerCoreOptions {
+export interface FakerOptions {
   /**
    * The locale definitions to use. If not provided, this core will not have any locale data and thus all methods that rely on locale data will throw an error when called.
    *
@@ -82,7 +82,7 @@ export interface FakerCoreOptions {
  *
  * @since 10.4.0
  */
-export function createFakerCore(options: FakerCoreOptions = {}): FakerCore {
+export function createFakerCore(options: FakerOptions = {}): FakerCore {
   const { locale, randomizer, config, seed } = options;
 
   if (randomizer != null && seed != null) {
diff --git a/src/faker.ts b/src/faker.ts
index c1a3ca17539..ff7dd9a244e 100644
--- a/src/faker.ts
+++ b/src/faker.ts
@@ -1,4 +1,4 @@
-import type { FakerCoreOptions } from './core';
+import type { FakerOptions } from './core';
 import type { LocaleDefinition, MetadataDefinition } from './definitions';
 import type { LocaleProxy } from './internal/locale-proxy';
 import { createLocaleProxy } from './internal/locale-proxy';
@@ -122,7 +122,7 @@ export class Faker extends SimpleFaker {
    *
    * @since 8.0.0
    */
-  constructor(options: FakerCoreOptions) {
+  constructor(options: FakerOptions) {
     super(options);
 
     this.definitions = createLocaleProxy(this.fakerCore.locale);
@@ -143,5 +143,3 @@ export class Faker extends SimpleFaker {
     return this.fakerCore.locale.metadata ?? {};
   }
 }
-
-export type FakerOptions = ConstructorParameters<typeof Faker>[0];
diff --git a/src/index.ts b/src/index.ts
index c100642a9e5..9a7c4288434 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,3 +1,4 @@
+export type { FakerOptions } from './core';
 export type {
   AirlineDefinition,
   AnimalDefinition,
@@ -30,7 +31,6 @@ export type {
 } from './definitions';
 export { FakerError } from './errors/faker-error';
 export { Faker } from './faker';
-export type { FakerOptions } from './faker';
 export * from './locale';
 export { fakerEN as faker } from './locale';
 export * from './locales';
diff --git a/src/simple-faker.ts b/src/simple-faker.ts
index bdf720ee191..4a721d8130d 100644
--- a/src/simple-faker.ts
+++ b/src/simple-faker.ts
@@ -1,4 +1,4 @@
-import type { FakerCore, FakerCoreOptions } from './core';
+import type { FakerCore, FakerOptions } from './core';
 import { createFakerCore } from './core';
 import { randomSeed } from './internal/seed';
 import { DatatypeModule } from './modules/datatype';
@@ -120,7 +120,7 @@ export class SimpleFaker {
    *
    * @since 8.1.0
    */
-  constructor(options?: FakerCoreOptions) {
+  constructor(options?: FakerOptions) {
     this.fakerCore = createFakerCore(options);
   }
 

From 24bb1bf7c20586ce04d4b14ba15f30162f4d4da0 Mon Sep 17 00:00:00 2001
From: ST-DDT <ST-DDT@gmx.de>
Date: Sun, 22 Mar 2026 21:17:43 +0100
Subject: [PATCH 08/11] chore: export new functions and types

---
 src/index.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/index.ts b/src/index.ts
index 9a7c4288434..641380ca80a 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,4 +1,6 @@
-export type { FakerOptions } from './core';
+export type { FakerConfig } from './config';
+export { createFakerCore } from './core';
+export type { FakerCore, FakerOptions } from './core';
 export type {
   AirlineDefinition,
   AnimalDefinition,

From 54add10e20aee196ea3c5d0476725859ede947be Mon Sep 17 00:00:00 2001
From: ST-DDT <ST-DDT@gmx.de>
Date: Sun, 29 Mar 2026 20:30:36 +0200
Subject: [PATCH 09/11] chore: edit after review

---
 src/core.ts         | 13 +++++++++----
 src/simple-faker.ts |  4 +++-
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/core.ts b/src/core.ts
index f3c7efd138b..f85e3b7dd5d 100644
--- a/src/core.ts
+++ b/src/core.ts
@@ -83,15 +83,20 @@ export interface FakerOptions {
  * @since 10.4.0
  */
 export function createFakerCore(options: FakerOptions = {}): FakerCore {
-  const { locale, randomizer, config, seed } = options;
+  const {
+    locale = {},
+    randomizer = generateMersenne53Randomizer(),
+    config = {},
+    seed,
+  } = options;
 
   if (randomizer != null && seed != null) {
     randomizer.seed(seed);
   }
 
   return {
-    locale: Array.isArray(locale) ? mergeLocales(locale) : (locale ?? {}),
-    randomizer: randomizer ?? generateMersenne53Randomizer(seed),
-    config: config ?? {},
+    locale: Array.isArray(locale) ? mergeLocales(locale) : locale,
+    randomizer,
+    config,
   };
 }
diff --git a/src/simple-faker.ts b/src/simple-faker.ts
index 4a721d8130d..e3e90cb24ed 100644
--- a/src/simple-faker.ts
+++ b/src/simple-faker.ts
@@ -8,6 +8,8 @@ import { SimpleLocationModule } from './modules/location';
 import { NumberModule } from './modules/number';
 import { StringModule } from './modules/string';
 
+export const DEFAULT_REF_DATE_SOURCE: () => Date = () => new Date();
+
 /**
  * This is a simplified Faker class that doesn't need any localized data to generate its output.
  *
@@ -40,7 +42,7 @@ export class SimpleFaker {
    * Gets a new reference date used to generate relative dates.
    */
   get defaultRefDate(): () => Date {
-    return this.fakerCore.config.defaultRefDate ?? (() => new Date());
+    return this.fakerCore.config.defaultRefDate ?? DEFAULT_REF_DATE_SOURCE;
   }
 
   /**

From 1f3f42c8ca5c1f21154e29efe26915960af76623 Mon Sep 17 00:00:00 2001
From: ST-DDT <ST-DDT@gmx.de>
Date: Wed, 8 Apr 2026 18:44:34 +0200
Subject: [PATCH 10/11] chore: remove comment

---
 src/faker.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/faker.ts b/src/faker.ts
index b06c9073863..18352f37261 100644
--- a/src/faker.ts
+++ b/src/faker.ts
@@ -83,7 +83,6 @@ export class Faker extends SimpleFaker {
   readonly word: WordModule = new WordModule(this);
 
   get rawDefinitions(): LocaleDefinition {
-    // TODO @ST-DDT 2024-05-14: Should we deprecate this?
     return this.fakerCore.locale;
   }
 

From 0c2e3de358fb58c2efe28e7fdd7bb4c2d6a9dcfa Mon Sep 17 00:00:00 2001
From: ST-DDT <ST-DDT@gmx.de>
Date: Wed, 8 Apr 2026 18:46:44 +0200
Subject: [PATCH 11/11] chore: bump since version

---
 src/core.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/core.ts b/src/core.ts
index f85e3b7dd5d..b661f6490cf 100644
--- a/src/core.ts
+++ b/src/core.ts
@@ -80,7 +80,7 @@ export interface FakerOptions {
  * createFakerCore() // no locale data, default randomizer and empty config
  * createFakerCore({ locale: en }) // custom locale data, default randomizer and empty config
  *
- * @since 10.4.0
+ * @since 10.5.0
  */
 export function createFakerCore(options: FakerOptions = {}): FakerCore {
   const {