fix: improve esm detection with export declartion (#27)

unjs · Dec 17, 2021 · 0511a93 · 0511a93
1 parent 660d0ad
commit 0511a93
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Showing 2 changed files with 5 additions and 3 deletions.
diff --git a/src/syntax.ts b/src/syntax.ts
@@ -5,7 +5,7 @@ import { ResolveOptions, resolvePath } from './resolve'
 import { isNodeBuiltin } from './utils'
 import { getProtocol } from './_utils'
 
-const ESM_RE = /([\s;]|^)(import[\w,{}\s*]*from|import\s*['"*{]|export\b\s*([*{]|default|type)|import\.meta\b)/m
+const ESM_RE = /([\s;]|^)(import[\w,{}\s*]*from|import\s*['"*{]|export\b\s*(?:[*{]|default|type|function|const|var|let|async function)|import\.meta\b)/m
 
 const BUILTIN_EXTENSIONS = new Set(['.mjs', '.cjs', '.node', '.wasm'])
 
@@ -82,7 +82,7 @@ export async function isValidNodeImport (id: string, _opts: ValidNodeImportOptio
   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)
+  const code = opts.code || await fsp.readFile(resolvedPath, 'utf-8').catch(() => null) || ''
 
   return hasCJSSyntax(code) || !hasESMSyntax(code)
 }
diff --git a/test/syntax.test.mjs b/test/syntax.test.mjs
@@ -14,10 +14,12 @@ const staticTests = {
   'import defaultExport, { export1, export2 } from "module-name";': { hasESM: true, hasCJS: false, isMixed: false },
   'import defaultExport, * as name from"module-name";': { hasESM: true, hasCJS: false, isMixed: false },
   'import"module-name"': { hasESM: true, hasCJS: false, isMixed: false },
-  //
   'import defaultMember from "module-name";': { hasESM: true, hasCJS: false, isMixed: false },
   'import "./file.mjs"': { hasESM: true, hasCJS: false, isMixed: false },
   'export default b=""': { hasESM: true, hasCJS: false, isMixed: false },
+  'export const a = 1': { hasESM: true, hasCJS: false, isMixed: false },
+  'export function hi() {}': { hasESM: true, hasCJS: false, isMixed: false },
+  'export async function foo() {}': { hasESM: true, hasCJS: false, isMixed: false },
   // CJS
   'exports.c={}': { hasESM: false, hasCJS: true, isMixed: false },
   'const b=true;module.exports={b};': { hasESM: false, hasCJS: true, isMixed: false },