join-no-has-trap.js

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// Test that Array.prototype.join doesn't call the [[HasProperty]] internal

// method of objects.

var log = [];

var array = [];

var proxy = new Proxy(array, new Proxy({}, {

    get(t, trap, r) {

      return (t, pk, ...more) => {

        log.push(`${trap}:${String(pk)}`);

        return Reflect[trap](t, pk, ...more);

};

}));

var result;

result = Array.prototype.join.call(proxy);

assertEqArray(log, [ "get:length" ]);

assertEq(result, "");

log.length = 0;

array.push(1);

result = Array.prototype.join.call(proxy);

assertEqArray(log, [ "get:length", "get:0" ]);

assertEq(result, "1");

log.length = 0;

array.push(2);

result = Array.prototype.join.call(proxy);

assertEqArray(log, [ "get:length", "get:0", "get:1" ]);

assertEq(result, "1,2");

if (typeof reportCompare === "function")

  reportCompare(true, true);