From 5adf8152bf4074168abf651c6fef81d34b351071 Mon Sep 17 00:00:00 2001
From: sosukesuzuki <aosukeke@gmail.com>
Date: Fri, 27 Aug 2021 11:08:58 +0900
Subject: [PATCH] Add tests

---
 packages/babel-parser/test/error-codes.js | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/packages/babel-parser/test/error-codes.js b/packages/babel-parser/test/error-codes.js
index 58bb5e411a6c..a072b0d7821a 100644
--- a/packages/babel-parser/test/error-codes.js
+++ b/packages/babel-parser/test/error-codes.js
@@ -18,4 +18,25 @@ describe("error codes", function () {
     expect(error.code).toBe("BABEL_PARSER_SYNTAX_ERROR");
     expect(error.reasonCode).toBe("MissingSemicolon");
   });
+  it("consistent reasonCode between Flow and TypeScript in Babel 8", () => {
+    const code = `function f([]?) {}`;
+    const {
+      errors: [tsError],
+    } = parse(code, {
+      errorRecovery: true,
+      plugins: ["typescript"],
+    });
+    const {
+      errors: [flowError],
+    } = parse(code, {
+      errorRecovery: true,
+      plugins: ["flow"],
+    });
+    expect(flowError.reasonCode).toBe(
+      process.env.BABEL_8_BREAKING
+        ? tsError.reasonCode
+        : "OptionalBindingPattern",
+    );
+    expect(flowError.message).toBe(tsError.message);
+  });
 });