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// Tests that newer-type functions (i.e. anything not defined by regular function declarations and
// expressions) throw when accessing their 'arguments' and 'caller' properties.
// 9.2.7 (AddRestrictedFunctionProperties) defines accessors on Function.prototype which throw on
// every 'get' and 'set' of 'caller' and 'arguments'.
// Additionally, 16.2 (Forbidden Extensions) forbids adding properties to all non-"legacy" function
// declarations and expressions. This creates the effect that all newer-style functions act like
// strict-mode functions when accessing their 'caller' and 'arguments' properties.
const container = {
async asyncMethod() {},
*genMethod() {},
method() {},
get getterMethod() {},
set setterMethod(x) {},
};
function* genDecl(){}
async function asyncDecl(){}
class classDecl {}
class extClassDecl extends Object {}
class classDeclExplicitCtor { constructor(){} }
class extClassDeclExplicitCtor extends Object { constructor(){} }
const functions = [
// Declarations
genDecl,
asyncDecl,
classDecl,
extClassDecl,
classDeclExplicitCtor,
extClassDeclExplicitCtor,
// Expressions
async function(){},
function*(){},
() => {},
async () => {},
class {},
class extends Object {},
class { constructor(){} },
class extends Object { constructor(){} },
// Methods
container.asyncMethod,
container.genMethod,
container.method,
Object.getOwnPropertyDescriptor(container, "getterMethod").get,
Object.getOwnPropertyDescriptor(container, "setterMethod").set,
// Bound functions
function(){}.bind(),
// Built-ins (native and self-hosted)
Function,
Function.prototype.bind,
];
const supportsAsyncGenerator = (function() {
try {
eval("async function* f(){}");
return true;
} catch (e) {
return false;
}
})();
if (supportsAsyncGenerator) {
eval(`
async function* asyncGenDecl(){}
functions.push(asyncGenDecl);
functions.push(async function*(){});
functions.push({async* asyncGenerator(){}}.asyncGenerator);
`);
}
functions.forEach(f => {
checkArgumentsAccess(f);
checkCallerAccess(f);
});
function checkArgumentsAccess(f) {
assertThrowsInstanceOf(() => f.arguments, TypeError,
`Expected 'arguments' property access to throw on ${f}`);
}
function checkCallerAccess(f) {
assertThrowsInstanceOf(() => f.caller, TypeError,
`Expected 'caller' property access to throw on ${f}`);
}
if (typeof reportCompare === "function")
reportCompare(true, true);