From 2c69ab3fac38cc887618855f2231ac2bdebe4a1b Mon Sep 17 00:00:00 2001
From: liuxingbaoyu <30521560+liuxingbaoyu@users.noreply.github.com>
Date: Mon, 10 Oct 2022 23:54:36 +0800
Subject: [PATCH] fix

---
 packages/babel-generator/src/printer.ts |  6 +++---
 packages/babel-generator/test/index.js  | 11 +++++++++++
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/packages/babel-generator/src/printer.ts b/packages/babel-generator/src/printer.ts
index 9acbe5dd4bee..48e28b31cf1e 100644
--- a/packages/babel-generator/src/printer.ts
+++ b/packages/babel-generator/src/printer.ts
@@ -950,9 +950,9 @@ class Printer {
       for (let i = 0; i < len; i++) {
         const comment = comments[i];
 
-        if (hasLoc && "loc" in comment && !this._printedComments.has(comment)) {
-          const commentStartLine = comment.loc?.start.line;
-          const commentEndLine = comment.loc?.end.line;
+        if (hasLoc && comment.loc && !this._printedComments.has(comment)) {
+          const commentStartLine = comment.loc.start.line;
+          const commentEndLine = comment.loc.end.line;
           if (type === COMMENT_TYPE.LEADING) {
             let offset = 0;
             if (i === 0) {
diff --git a/packages/babel-generator/test/index.js b/packages/babel-generator/test/index.js
index f965e149d696..d5117a452555 100644
--- a/packages/babel-generator/test/index.js
+++ b/packages/babel-generator/test/index.js
@@ -472,6 +472,17 @@ describe("generation", function () {
 
     expect(generate(ast).code).toBe("/*#__PURE__*/a();\n/*#__PURE__*/b();");
   });
+
+  it("comments with null or undefined loc", () => {
+    const code = "/*#__PURE__*/ /*#__PURE__*/";
+
+    const ast = parse(code);
+
+    ast.comments[0].loc = null;
+    ast.comments[1].loc = undefined;
+
+    expect(generate(ast).code).toBe("/*#__PURE__*/\n/*#__PURE__*/");
+  });
 });
 
 describe("programmatic generation", function () {