Fix crash on certain EOFs

micromark · Apr 21, 2022 · e84da9e · e84da9e
1 parent bfdcc31
commit e84da9e
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Showing 2 changed files with 22 additions and 3 deletions.
diff --git a/dev/lib/syntax.js b/dev/lib/syntax.js
@@ -110,11 +110,11 @@ export function mdxjsEsm(options) {
     /** @type {State} */
     function rest(code) {
       if (code === codes.eof) {
-        return atEnd(code)
+        return atEndOfData(code)
       }
 
       if (markdownLineEnding(code)) {
-        return effects.check(nextBlankConstruct, atEnd, atEol)(code)
+        return effects.check(nextBlankConstruct, atEndOfData, atEol)(code)
       }
 
       effects.consume(code)
@@ -136,14 +136,22 @@ export function mdxjsEsm(options) {
         return lineStart
       }
 
+      if (code === codes.eof) {
+        return atEnd(code)
+      }
+
       effects.enter('mdxjsEsmData')
       return rest(code)
     }
 
     /** @type {State} */
-    function atEnd(code) {
+    function atEndOfData(code) {
       effects.exit('mdxjsEsmData')
+      return atEnd(code)
+    }
 
+    /** @type {State} */
+    function atEnd(code) {
       let index = -1
       const result = eventsToAcorn(self.events.slice(eventStart), {
         acorn,

diff --git a/test/index.js b/test/index.js
@@ -265,6 +265,17 @@ test('micromark-extension-mdxjs-esm', (t) => {
     'should support JSX if an `acorn` instance supporting it is passed in'
   )
 
+  t.throws(
+    () => {
+      micromark('export {a}\n', {
+        extensions: [syntax({acorn: acorn.Parser.extend(jsx())})],
+        htmlExtensions: [html]
+      })
+    },
+    /Export 'a' is not defined/,
+    'should support EOF after EOL'
+  )
+
   t.throws(
     () => {
       micromark('export var a = () => {}\n\nb', {