fix: isPackageExists checks for the package incorrectly, close #125

Author: pengzhanbo

vite-plugin-mock-dev-server/src/compiler/compile.ts

@@ -1,17 +1,14 @@
 import type { CompilerOptions, CompilerResult, MockRawData, TransformResult } from './types'
 import process from 'node:process'
-import { isPackageExists } from 'local-pkg'
+import { isPackageExists } from '../utils'
 import { transformWithEsbuild } from './esbuild'
 import { loadFromCode } from './loadFromCode'
 import { transformWithRolldown } from './rolldown'
 
-const hasRolldown = isPackageExists('rolldown')
-const hasEsbuild = isPackageExists('esbuild')
-
 export async function transform(entryPoint: string, options: CompilerOptions): Promise<TransformResult> {
-  if (hasRolldown)
+  if (await isPackageExists('rolldown'))
     return transformWithRolldown(entryPoint, options)
-  if (hasEsbuild)
+  if (await isPackageExists('esbuild'))
     return transformWithEsbuild(entryPoint, options)
   throw new Error('rolldown or esbuild not found')
 }

vite-plugin-mock-dev-server/src/utils/is.ts

@@ -1,4 +1,5 @@
 import type { Readable, Stream } from 'node:stream'
+import { hasOwn } from '@pengzhanbo/utils'
 
 export function isStream(stream: unknown): stream is Stream {
   return stream !== null
@@ -12,3 +13,25 @@ export function isReadableStream(stream: unknown): stream is Readable {
     && typeof (stream as any)._read === 'function'
     && typeof (stream as any)._readableState === 'object'
 }
+
+const PACKAGE_CACHE: Record<string, boolean> = {}
+
+export async function isPackageExists(mod: string): Promise<boolean> {
+  if (hasOwn(PACKAGE_CACHE, mod)) {
+    return PACKAGE_CACHE[mod]
+  }
+  try {
+    // @ts-expect-error fallback for node
+    if (import.meta.resolve) {
+      PACKAGE_CACHE[mod] = !!import.meta.resolve(mod)
+    }
+    else {
+      await import(mod)
+      PACKAGE_CACHE[mod] = true
+    }
+    return PACKAGE_CACHE[mod]
+  }
+  catch {}
+  PACKAGE_CACHE[mod] = false
+  return false
+}