superPropMegamorphic.js

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// Test GETPROP_SUPER with megamorphic variation

const NCLASS = 20;

var g_prop = "prop";

var g_THIS = "THIS";

// Define array of base classes with a data property and a getter property.

let C = [];

for (let i = 0; i < NCLASS; ++i) {

    let klass = class {

        get THIS() { return this; }

};

    klass.prototype.prop = i;

    C.push(klass);

// Derive class using super property access

class D extends C[0] {

    get prop() { return super.prop; }

    get elem() { return super[g_prop]; }

    get prop_this() { return super.THIS; }

    get elem_this() { return super[g_THIS]; }

let d = new D();

for (var j = 0; j < 4; ++j) {

    for (var i = 0; i < 15; ++i) {

        // Change base class by overriding [[HomeObject]].[[Prototype]]

        Object.setPrototypeOf(D.prototype, C[j].prototype);

        // Check we get property of correct class

        assertEq(d.prop, j);

        assertEq(d.elem, j);

        // Check super getter gets |this| of object not base class

        assertEq(d.prop_this, d);

        assertEq(d.elem_this, d);