According to ES standard, the identifier arguments cannot appear to the left of the assignment operator only in strict mode. However, when running this testcase blow which is in non-strict mode, hermes throws an expection. Why does this happen? Is this a feature of hermes?

revision

044cf4b

Test case

var NISLFuzzingFunc = function() {
    arguments = 10;
    print(arguments);
};
NISLFuzzingFunc();

Command

./build/bin/hermes -w testcase.js

Output

 testcase.js:2:5: error: invalid assignment left-hand side
 arguments = 10;

Expected behavior

10