feat: add isValidNodeImport utility (#16)

package.json

@@ -30,8 +30,9 @@
     "import-meta-resolve": "^1.1.1",
     "jiti": "^1.12.5",
     "mocha": "^9.1.2",
+    "pathe": "^0.2.0",
+    "pkg-types": "^0.3.1",
     "standard-version": "latest",
-    "unbuild": "^0.5.7",
-    "pathe": "^0.2.0"
+    "unbuild": "^0.5.7"
   }
 }

src/syntax.ts

@@ -1,5 +1,12 @@
+import { promises as fsp } from 'fs'
+import { extname } from 'pathe'
+import { readPackageJSON } from 'pkg-types'
+import { ResolveOptions, resolvePath } from './resolve'
+
 const ESM_RE = /([\s;]|^)(import[\s'"*{]|export\b|import\.meta\b)/m
 
+const BUILTIN_EXTENSIONS = new Set(['.mjs', '.cjs', '.node', '.wasm'])
+
 export function hasESMSyntax (code: string): boolean {
   return ESM_RE.test(code)
 }
@@ -19,3 +26,27 @@ export function detectSyntax (code: string) {
     isMixed: hasESM && hasCJS
   }
 }
+
+export async function isValidNodeImport (id: string, opts: ResolveOptions & { code?: string } = {}): Promise<boolean> {
+  const resolvedPath = await resolvePath(id, opts)
+  const extension = extname(resolvedPath)
+
+  if (BUILTIN_EXTENSIONS.has(extension)) {
+    return true
+  }
+
+  if (extension !== '.js') {
+    return false
+  }
+
+  if (resolvedPath.match(/\.(\w+-)?esm?(-\w+)?\.js$/)) {
+    return false
+  }
+
+  const pkg = await readPackageJSON(resolvedPath).catch(() => null)
+  if (pkg?.type === 'module') { return true }
+
+  const code = opts.code || await fsp.readFile(resolvedPath, 'utf-8').catch(() => null)
+
+  return !hasESMSyntax(code)
+}

yarn.lock

@@ -2485,6 +2485,11 @@ mlly@^0.2.6:
   dependencies:
     import-meta-resolve "^1.1.1"
 
+mlly@^0.3.6:
+  version "0.3.6"
+  resolved "https://registry.yarnpkg.com/mlly/-/mlly-0.3.6.tgz#639867d616569d12a4aa1dff99f18a5e63126941"
+  integrity sha512-mSEVMwiNEjppuRmhfzWQgzZtC/N2eWiDAhIfTM1U4fO0zJjacJRDnaT//qNlmNbeWQn3fzDSA5UC6jsvAfL4AA==
+
 mocha@^9.1.2:
   version "9.1.2"
   resolved "https://registry.yarnpkg.com/mocha/-/mocha-9.1.2.tgz#93f53175b0f0dc4014bd2d612218fccfcf3534d3"
@@ -2801,6 +2806,15 @@ pkg-dir@^2.0.0:
   dependencies:
     find-up "^2.1.0"
 
+pkg-types@^0.3.1:
+  version "0.3.1"
+  resolved "https://registry.yarnpkg.com/pkg-types/-/pkg-types-0.3.1.tgz#d7a8b69efb8777a05afc5aabfc259a29a5d6d159"
+  integrity sha512-BjECNgz/tsyqg0/T4Z/U7WbFQXUT24nfkxPbALcrk/uHVeZf9MrGG4tfvYtu+jsrHCFMseLQ6woQddDEBATw3A==
+  dependencies:
+    jsonc-parser "^3.0.0"
+    mlly "^0.3.6"
+    pathe "^0.2.0"
+
 pkg-up@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/pkg-up/-/pkg-up-2.0.0.tgz#c819ac728059a461cab1c3889a2be3c49a004d7f"