From 0d9ad433b47878aa1de6edd324c6dcd4cb1e2d7f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicol=C3=B2=20Ribaudo?= <nicolo.ribaudo@gmail.com>
Date: Tue, 2 Mar 2021 08:16:25 +0100
Subject: [PATCH] Fix `esmodules: true` without specified browsers (#12908)

* Fix `esmodules: true` without specified browsers

* fix
---
 config.js                                                   | 3 +++
 packages/babel-helper-compilation-targets/src/index.js      | 2 +-
 .../test/targets-parser.spec.js                             | 6 ++++++
 .../fixtures/sanity/top-level-targets-esmodules/input.js    | 1 +
 .../sanity/top-level-targets-esmodules/options.json         | 4 ++++
 .../fixtures/sanity/top-level-targets-esmodules/output.js   | 1 +
 6 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 config.js
 create mode 100644 packages/babel-preset-env/test/fixtures/sanity/top-level-targets-esmodules/input.js
 create mode 100644 packages/babel-preset-env/test/fixtures/sanity/top-level-targets-esmodules/options.json
 create mode 100644 packages/babel-preset-env/test/fixtures/sanity/top-level-targets-esmodules/output.js

diff --git a/config.js b/config.js
new file mode 100644
index 000000000000..594300ed742b
--- /dev/null
+++ b/config.js
@@ -0,0 +1,3 @@
+module.exports = {
+  targets: { esmodules: true },
+};
diff --git a/packages/babel-helper-compilation-targets/src/index.js b/packages/babel-helper-compilation-targets/src/index.js
index b6ce5284ecb4..be5861d6ca31 100644
--- a/packages/babel-helper-compilation-targets/src/index.js
+++ b/packages/babel-helper-compilation-targets/src/index.js
@@ -205,7 +205,7 @@ export default function getTargets(
 
   // `esmodules` as a target indicates the specific set of browsers supporting ES Modules.
   // These values OVERRIDE the `browsers` field.
-  if (esmodules && (esmodules !== "intersect" || !browsers)) {
+  if (esmodules && (esmodules !== "intersect" || !browsers?.length)) {
     browsers = Object.keys(ESM_SUPPORT)
       .map(browser => `${browser} >= ${ESM_SUPPORT[browser]}`)
       .join(", ");
diff --git a/packages/babel-helper-compilation-targets/test/targets-parser.spec.js b/packages/babel-helper-compilation-targets/test/targets-parser.spec.js
index 2119db119928..e9c78872a0de 100644
--- a/packages/babel-helper-compilation-targets/test/targets-parser.spec.js
+++ b/packages/babel-helper-compilation-targets/test/targets-parser.spec.js
@@ -267,6 +267,12 @@ describe("getTargets", () => {
     });
 
     it("'intersect' behaves like 'true' if no browsers are specified", () => {
+      expect(getTargets({ esmodules: "intersect" })).toEqual(
+        getTargets({ esmodules: true }, { ignoreBrowserslistConfig: true }),
+      );
+    });
+
+    it("'intersect' behaves like 'true' if no browsers are specified and the browserslist config is ignored", () => {
       expect(
         getTargets(
           { esmodules: "intersect" },
diff --git a/packages/babel-preset-env/test/fixtures/sanity/top-level-targets-esmodules/input.js b/packages/babel-preset-env/test/fixtures/sanity/top-level-targets-esmodules/input.js
new file mode 100644
index 000000000000..3738b805a105
--- /dev/null
+++ b/packages/babel-preset-env/test/fixtures/sanity/top-level-targets-esmodules/input.js
@@ -0,0 +1 @@
+a ** b;
diff --git a/packages/babel-preset-env/test/fixtures/sanity/top-level-targets-esmodules/options.json b/packages/babel-preset-env/test/fixtures/sanity/top-level-targets-esmodules/options.json
new file mode 100644
index 000000000000..01263ed505b3
--- /dev/null
+++ b/packages/babel-preset-env/test/fixtures/sanity/top-level-targets-esmodules/options.json
@@ -0,0 +1,4 @@
+{
+  "targets": { "esmodules": true },
+  "presets": ["env"]
+}
diff --git a/packages/babel-preset-env/test/fixtures/sanity/top-level-targets-esmodules/output.js b/packages/babel-preset-env/test/fixtures/sanity/top-level-targets-esmodules/output.js
new file mode 100644
index 000000000000..3738b805a105
--- /dev/null
+++ b/packages/babel-preset-env/test/fixtures/sanity/top-level-targets-esmodules/output.js
@@ -0,0 +1 @@
+a ** b;