From d778427ec9c624246baa2553cec43254c8afbdbb Mon Sep 17 00:00:00 2001
From: Martin Forsgren <martin@visly.app>
Date: Tue, 11 Feb 2020 10:34:21 +0100
Subject: [PATCH] Respect preserveComments option in tempate.ast() (#11112)

---
 packages/babel-template/src/options.js |  2 +-
 packages/babel-template/test/index.js  | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/packages/babel-template/src/options.js b/packages/babel-template/src/options.js
index 07230cf1cf0b..b1c6f38a6e86 100644
--- a/packages/babel-template/src/options.js
+++ b/packages/babel-template/src/options.js
@@ -131,7 +131,7 @@ export function validate(opts: mixed): TemplateOpts {
     placeholderWhitelist: placeholderWhitelist || undefined,
     placeholderPattern:
       placeholderPattern == null ? undefined : placeholderPattern,
-    preserveComments: preserveComments == null ? false : preserveComments,
+    preserveComments: preserveComments == null ? undefined : preserveComments,
     syntacticPlaceholders:
       syntacticPlaceholders == null ? undefined : syntacticPlaceholders,
   };
diff --git a/packages/babel-template/test/index.js b/packages/babel-template/test/index.js
index ebac1d142d7e..58e552e94049 100644
--- a/packages/babel-template/test/index.js
+++ b/packages/babel-template/test/index.js
@@ -28,6 +28,18 @@ describe("@babel/template", function() {
     expect(generator(output).code).toBe(comments);
   });
 
+  it("should preserve comments with a flag", function() {
+    const output = template(comments, { preserveComments: true })();
+    expect(generator(output).code).toBe(comments);
+  });
+
+  it("should preserve comments with a flag when using .ast", function() {
+    const output1 = template.ast(comments, { preserveComments: true });
+    const output2 = template({ preserveComments: true }).ast(comments);
+    expect(generator(output1).code).toBe(comments);
+    expect(generator(output2).code).toBe(comments);
+  });
+
   describe("string-based", () => {
     it("should handle replacing values from an object", () => {
       const value = t.stringLiteral("some string value");