From 85d50f956839caca90c5f4c7bb4ec70a53119141 Mon Sep 17 00:00:00 2001
From: Felix Gnass <fgnass@gmail.com>
Date: Fri, 25 May 2018 10:27:35 +0200
Subject: [PATCH] feat: support flow comment types

---
 src/parsers/parse_to_ast.js | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/parsers/parse_to_ast.js b/src/parsers/parse_to_ast.js
index 1cd3ca22f..6be0c1710 100644
--- a/src/parsers/parse_to_ast.js
+++ b/src/parsers/parse_to_ast.js
@@ -21,6 +21,20 @@ const opts = {
   ]
 };
 
+/**
+ * Convert flow comment types into flow annotations so that
+ * they end up in the final AST. If the source does not contain
+ * a flow pragma, the code is returned verbatim.
+ * @param {*} source code with flow type comments
+ * @returns {string} code with flow annotations
+ */
+function commentToFlow(source) {
+  if (!/@flow/.test(source)) return source;
+  return source
+    .replace(/\/\*::([^]+?)\*\//g, '$1')
+    .replace(/\/\*:\s*([^]+?)\s*\*\//g, ':$1');
+}
+
 export function parseToAst(source: string) {
-  return babylon.parse(source, opts);
+  return babylon.parse(commentToFlow(source), opts);
 }