fix(types): app config types extending from schema

[Atinux]

🔗 Linked issue

❓ Type of change

• 📖 Documentation (updates to the documentation, readme or JSdoc annotations)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

Related also to nuxt-modules/icon#62

If we use the schema to specify the app config types, I expect the types to be in the app config types (not only input).

Though, we may want to use DeepPartial since those values may not exists in the app.config object.

Happy to get your feedback @danielroe and @pi0

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

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[danielroe]

We're currently doing the merging here:

nuxt/packages/nuxt/src/core/templates.ts

Lines 213 to 245 in f366ab4

	export const appConfigDeclarationTemplate: NuxtTemplate = {
	filename: 'types/app.config.d.ts',
	getContents: ({ app, nuxt }) => {
	return `
	import type { CustomAppConfig } from 'nuxt/schema'
	import type { Defu } from 'defu'
	${app.configs.map((id: string, index: number) => `import ${`cfg${index}`} from ${JSON.stringify(id.replace(/(?<=\w)\.\w+$/g, ''))}`).join('\n')}
	declare const inlineConfig = ${JSON.stringify(nuxt.options.appConfig, null, 2)}
	type ResolvedAppConfig = Defu<typeof inlineConfig, [${app.configs.map((_id: string, index: number) => `typeof cfg${index}`).join(', ')}]>
	type IsAny<T> = 0 extends 1 & T ? true : false
	type MergedAppConfig<Resolved extends Record<string, any>, Custom extends Record<string, any>> = {
	[K in keyof Resolved]: K extends keyof Custom
	? IsAny<Custom[K]> extends true
	? Resolved[K]
	: Custom[K] extends Record<string, any>
	? Resolved[K] extends Record<string, any>
	? MergedAppConfig<Resolved[K], Custom[K]>
	: Exclude<Custom[K], undefined>
	: Exclude<Custom[K], undefined>
	: Resolved[K]
	}
	declare module 'nuxt/schema' {
	interface AppConfig extends MergedAppConfig<ResolvedAppConfig, CustomAppConfig> { }
	}
	declare module '@nuxt/schema' {
	interface AppConfig extends MergedAppConfig<ResolvedAppConfig, CustomAppConfig> { }
	}
	`
	}
	}

We also have a type test for it:

nuxt/test/fixtures/basic/types.ts

Line 297 in 574a561

userConfig: 123 | 456

I believe the issue is with nuxt-config-schema - when disabled in nuxt-icon the types appear to work as expected.

---

issue seems resolved since nuxt-modules/icon#70