Merge pull request #3158 from babel/paren-object

Parenthesize object expression when it may end up at the start of an expression

packages/babel-generator/src/node/parentheses.js

@@ -55,6 +55,13 @@ export function ObjectExpression(node: Object, parent: Object): boolean {
     return true;
   }
 
+  if ((t.isBinaryExpression(parent) || t.isLogicalExpression(parent)) && parent.left === node) {
+    // We'd need to check that the parent's parent is an ExpressionStatement. But this
+    // code doesn't make any sense to begin with and should be rare.
+    // `({}) === foo`
+    return true;
+  }
+
   return false;
 }
 

packages/babel-generator/test/fixtures/parentheses/object/actual.js

@@ -0,0 +1,2 @@
+({}) === foo;
+({}) && foo;

packages/babel-generator/test/fixtures/parentheses/object/expected.js

@@ -0,0 +1,2 @@
+({}) === foo;
+({}) && foo;