Missing parenthesis for await assignment expression argument

[Niklas Mischkulnig]

Motivation

Parenthesis need to be inserted around the await argument if it's an assignment expression

Input

Input:

var obj;
async function main() {
	return await (obj = Promise.resolve(1));
}

Script

const acorn = require("acorn");
const astring = require("astring");

const code = `var obj;
async function main() {
	return await (obj = Promise.resolve(1));
}
`;
const ast = acorn.parse(code, { ecmaVersion: 2020 });
const formattedCode = astring.generate(ast);
console.log(formattedCode);

/*

undefined:3
  return await obj = Promise.resolve(1);
         ^^^^^^^^^

SyntaxError: Invalid left-hand side in assignment

*/
eval(formattedCode);

Expected behavior

= same as input

var obj;
async function main() {
	return await (obj = Promise.resolve(1));
}

Actual behavior

var obj;
async function main() {
  return await obj = Promise.resolve(1);
}

[Niklas Mischkulnig]

I guess the fix would be the identical to this

astring/src/astring.js

Lines 690 to 694 in 00690ab

 if (node.argument.type === 'ArrowFunctionExpression') { 
   state.write('(') 
   this[node.argument.type](node.argument, state) 
   state.write(')') 
 } else { 

[David Bonnet]

@mischnic Thanks for reporting this, I'm fixing it now.

[David Bonnet]

Well, actually, the yield operator has a very low precedence. Fixed in d3af2fc.