feat: merge options deeply

changelog.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 - update default retroarch-emscripten-build version to v1.17.0
 - disable some default inputs in RetroArch
+- when some of the passed config items are objects, like `retroarchConfig`, they will be merged with the default items instead of overwriting the default items entirely
 
 ### Fixed
 - fix export name when using ESM build of retroarch

src/nostalgist.ts

@@ -10,6 +10,7 @@ import type {
  NostalgistOptionsPartial,
  NostalgistResolveFileFunction,
 } from './types/nostalgist-options'
+import { merge } from './utils'
 import { vendors } from './vendors'
 
 function baseName(url: string) {
@@ -29,10 +30,9 @@ export class Nostalgist {
  private emulator: Emulator | undefined
 
  private constructor(options: NostalgistLaunchOptions) {
- const mergedOptions = {
- ...Nostalgist.globalOptions,
- ...options,
- }
+ const mergedOptions = {}
+ merge(mergedOptions, Nostalgist.globalOptions, options)
+ // @ts-expect-error we cannot infer the final type here
  this.options = mergedOptions
  }
 
@@ -59,10 +59,7 @@ export class Nostalgist {
  * ```
  */
  static configure(options: NostalgistOptionsPartial) {
- Nostalgist.globalOptions = {
- ...Nostalgist.globalOptions,
- ...options,
- }
+ merge(Nostalgist.globalOptions, options)
  }
 
  /**
@@ -477,10 +474,8 @@ export class Nostalgist {
  }
 
  if (element) {
- return {
- ...defaultAppearanceStyle,
- ...style,
- }
+ merge(defaultAppearanceStyle, style)
+ return defaultAppearanceStyle
  }
 
  const defaultLayoutStyle: Partial<CSSStyleDeclaration> = {
@@ -491,11 +486,8 @@ export class Nostalgist {
  height: '100%',
  zIndex: '1',
  }
- return {
- ...defaultLayoutStyle,
- ...defaultAppearanceStyle,
- ...style,
- }
+ merge(defaultLayoutStyle, defaultAppearanceStyle, style)
+ return defaultLayoutStyle
  }
 
  private async getCoreOption() {
@@ -610,17 +602,15 @@ export class Nostalgist {
  }
 
  private getRetroarchOption() {
- return {
- ...Nostalgist.globalOptions.retroarchConfig,
- ...this.options.retroarchConfig,
- }
+ const options = {}
+ merge(options, Nostalgist.globalOptions.retroarchConfig, this.options.retroarchConfig)
+ return options as typeof this.options.retroarchConfig
  }
 
  private getRetroarchCoreOption() {
- return {
- ...Nostalgist.globalOptions.retroarchCoreConfig,
- ...this.options.retroarchCoreConfig,
- }
+ const options = {}
+ merge(options, Nostalgist.globalOptions.retroarchCoreConfig, this.options.retroarchCoreConfig)
+ return options
  }
 
  private loadEmulator() {

src/utils.ts

@@ -98,3 +98,39 @@ export async function importCoreJsAsESM({ name, js }: { name: string; js: string
  URL.revokeObjectURL(jsBlobUrl)
  }
 }
+
+function isNil(obj: unknown) {
+ return obj === undefined || obj === null
+}
+
+function isPrimitive(obj: unknown) {
+ if (isNil(obj)) {
+ return true
+ }
+ const type = typeof obj
+ const primitevTypes = ['string', 'number', 'boolean', 'bigint', 'symbol', 'function']
+ return primitevTypes.includes(type)
+}
+
+function mergeSourceToTarget(target: any, source: any) {
+ for (const key in source) {
+ if (Object.prototype.hasOwnProperty.call(source, key)) {
+ const targetValue = target[key]
+ const sourceValue = source[key]
+ if (isPrimitive(sourceValue)) {
+ target[key] = sourceValue
+ } else if (Array.isArray(targetValue) && Array.isArray(sourceValue)) {
+ target[key] = [...targetValue, ...sourceValue]
+ } else {
+ target[key] = isPrimitive(targetValue) ? {} : target[key]
+ merge(target[key], sourceValue)
+ }
+ }
+ }
+}
+
+export function merge(target: any, ...sources: any[]) {
+ for (const source of sources) {
+ mergeSourceToTarget(target, source)
+ }
+}

tests/integration/nostalgist.spec.ts

@@ -203,4 +203,29 @@ describe('nostalgist', () => {
  expect(file.fileContent.size).toBeGreaterThan(0)
  }
  })
+
+ test.only('Nostalgist.launch with nested options', async () => {
+ Nostalgist.configure({
+ retroarchConfig: {
+ input_audio_mute: 'a',
+ input_menu_toggle: 'nul',
+ },
+ })
+
+ const nostalgist = await Nostalgist.launch({
+ core: 'fceumm',
+ rom: 'flappybird.nes',
+ retroarchConfig: {
+ input_max_users: 4,
+ input_audio_mute: 'b',
+ },
+ })
+
+ const options = nostalgist.getOptions()
+ expect(options.retroarchConfig).toMatchObject({
+ menu_driver: 'rgui',
+ input_menu_toggle: 'nul',
+ input_audio_mute: 'b',
+ })
+ })
 })