fix: no node fs module in runtime

closes #840

src/layers/2_generator/files.ts

@@ -3,9 +3,9 @@ import { getPath } from '@dprint/typescript'
 import _ from 'json-bigint'
 import fs from 'node:fs/promises'
 import * as Path from 'node:path'
-import { fileExists } from '../../lib/prelude.js'
 import type { OptionsInput } from './generateCode.js'
 import { generateCode, type Input as GenerateInput } from './generateCode.js'
+import { fileExists } from './prelude.js'
 
 export interface Input {
   name?: string

src/layers/2_generator/prelude.ts

@@ -0,0 +1,13 @@
+import fs from 'node:fs/promises'
+import { errorFromMaybeError } from '../../lib/prelude.js'
+
+export const fileExists = async (path: string) => {
+  return Boolean(
+    await fs.stat(path).catch((_: unknown) => {
+      const error = errorFromMaybeError(_)
+      return `code` in error && typeof error.code === `string` && error.code === `ENOENT`
+        ? null
+        : Promise.reject(error)
+    }),
+  )
+}

src/lib/prelude.ts

@@ -1,3 +1,5 @@
+import type { ConditionalSimplifyDeep } from 'type-fest/source/conditional-simplify.js'
+
 /* eslint-disable */
 export type RemoveIndex<T> = {
   [K in keyof T as string extends K ? never : number extends K ? never : K]: T[K]
@@ -180,23 +182,8 @@ export type Values<T> = T[keyof T]
 
 export type GetKeyOr<T, Key, Or> = Key extends keyof T ? T[Key] : Or
 
-import type { ConditionalSimplifyDeep } from 'type-fest/source/conditional-simplify.js'
-
 export type SimplifyDeep<T> = ConditionalSimplifyDeep<T, Function | Iterable<unknown> | Date, object>
 
-import fs from 'node:fs/promises'
-
-export const fileExists = async (path: string) => {
-  return Boolean(
-    await fs.stat(path).catch((_: unknown) => {
-      const error = errorFromMaybeError(_)
-      return `code` in error && typeof error.code === `string` && error.code === `ENOENT`
-        ? null
-        : Promise.reject(error)
-    }),
-  )
-}
-
 export type As<T, U> = U extends T ? U : never
 
 export type UnionToIntersection<U> = (U extends any ? (k: U) => void : never) extends ((k: infer I) => void) ? I : never