From cbc73c0ccefc9467d6ba7e2b774214a2fba2bb45 Mon Sep 17 00:00:00 2001
From: Arun Kumar Mohan <arunmohandm@gmail.com>
Date: Thu, 2 Apr 2020 18:42:31 -0500
Subject: [PATCH] fix(logical-assignment): Do not assign names to anonymous
 functions

---
 .../src/index.js                              | 27 ++++++++++++++-----
 .../anonymous-function/input.js               |  2 ++
 .../anonymous-function/options.json           |  3 +++
 .../anonymous-function/output.js              |  2 ++
 4 files changed, 27 insertions(+), 7 deletions(-)
 create mode 100644 packages/babel-plugin-proposal-logical-assignment-operators/test/fixtures/logical-assignment/anonymous-function/input.js
 create mode 100644 packages/babel-plugin-proposal-logical-assignment-operators/test/fixtures/logical-assignment/anonymous-function/options.json
 create mode 100644 packages/babel-plugin-proposal-logical-assignment-operators/test/fixtures/logical-assignment/anonymous-function/output.js

diff --git a/packages/babel-plugin-proposal-logical-assignment-operators/src/index.js b/packages/babel-plugin-proposal-logical-assignment-operators/src/index.js
index 813dcd761f7c..2f2c84ff3271 100644
--- a/packages/babel-plugin-proposal-logical-assignment-operators/src/index.js
+++ b/packages/babel-plugin-proposal-logical-assignment-operators/src/index.js
@@ -39,13 +39,26 @@ export default declare(api => {
           }
         }
 
-        path.replaceWith(
-          t.logicalExpression(
-            operator.slice(0, -1),
-            lhs,
-            t.assignmentExpression("=", left, right),
-          ),
-        );
+        const isRHSAnonymousFunction = t.isFunctionExpression(right, {
+          id: null,
+        });
+        if (isRHSAnonymousFunction && operator === "??=") {
+          path.replaceWith(
+            t.assignmentExpression(
+              "=",
+              lhs,
+              t.logicalExpression("??", left, right),
+            ),
+          );
+        } else {
+          path.replaceWith(
+            t.logicalExpression(
+              operator.slice(0, -1),
+              lhs,
+              t.assignmentExpression("=", left, right),
+            ),
+          );
+        }
       },
     },
   };
diff --git a/packages/babel-plugin-proposal-logical-assignment-operators/test/fixtures/logical-assignment/anonymous-function/input.js b/packages/babel-plugin-proposal-logical-assignment-operators/test/fixtures/logical-assignment/anonymous-function/input.js
new file mode 100644
index 000000000000..f3eb2ecbfb5c
--- /dev/null
+++ b/packages/babel-plugin-proposal-logical-assignment-operators/test/fixtures/logical-assignment/anonymous-function/input.js
@@ -0,0 +1,2 @@
+var f;
+console.log((f ??= function () {}).name);
diff --git a/packages/babel-plugin-proposal-logical-assignment-operators/test/fixtures/logical-assignment/anonymous-function/options.json b/packages/babel-plugin-proposal-logical-assignment-operators/test/fixtures/logical-assignment/anonymous-function/options.json
new file mode 100644
index 000000000000..259c77d8e49c
--- /dev/null
+++ b/packages/babel-plugin-proposal-logical-assignment-operators/test/fixtures/logical-assignment/anonymous-function/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["proposal-logical-assignment-operators"]
+}
diff --git a/packages/babel-plugin-proposal-logical-assignment-operators/test/fixtures/logical-assignment/anonymous-function/output.js b/packages/babel-plugin-proposal-logical-assignment-operators/test/fixtures/logical-assignment/anonymous-function/output.js
new file mode 100644
index 000000000000..0e137241373e
--- /dev/null
+++ b/packages/babel-plugin-proposal-logical-assignment-operators/test/fixtures/logical-assignment/anonymous-function/output.js
@@ -0,0 +1,2 @@
+var f;
+console.log((f = f ?? function () {}).name);