blob: 862c2a59364b401a987935b41051b37e150f2e89 [file] [log] [blame]
function testSyntax(script) {
try {
eval(script);
} catch (error) {
if (error instanceof SyntaxError)
throw new Error("Bad error: " + String(error));
}
}
function testSyntaxError(script, message) {
var error = null;
try {
eval(script);
} catch (e) {
error = e;
}
if (!error)
throw new Error("Expected syntax error not thrown");
if (String(error) !== message)
throw new Error("Bad error: " + String(error));
}
testSyntaxError(`
class Hello {
get *gen() {
}
}
`, `SyntaxError: Unexpected token '*'. Expected an opening '(' before a method's parameter list.`);
testSyntaxError(`
class Hello {
set *gen(value) {
}
}
`, `SyntaxError: Unexpected token '*'. Expected an opening '(' before a method's parameter list.`);
testSyntaxError(`
function ** gen() { }
`, `SyntaxError: Unexpected token '**'`);
// "yield" is never a YieldExpression in a ConciseBody (per http://ecma-international.org/ecma-262/6.0/#sec-arrow-function-definitions
// and https://tc39.github.io/ecma262/#prod-ConciseBody)
testSyntax(`
var value = () => {
yield
}
`);
testSyntax(`
var value = (val = yield) => {
}
`);
// Confusingly, FormalParameters[~Yield] does not product a SyntaxError for "yield", even
// inside of a generator (https://tc39.github.io/ecma262/#prod-FunctionDeclaration),
// but instead resolves "yield" as a BindingIdentifier
testSyntax(`
function *gen() {
function ng(val = yield) {
}
}
`);
// Arrow formal parameters within Generators are parameterized with [+Yield], but are
// still forbidden from including YieldExpressions in ArrowFormalParameters.
// (https://tc39.github.io/ecma262/#prod-ArrowFormalParameters)
testSyntaxError(`
var yield;
function *gen() {
var ng = (val = yield) => {
}
}
`, `SyntaxError: Unexpected keyword 'yield'. Cannot use yield expression out of generator.`);
(function testYieldBindingIdentifier() {
var yield = "hello!";
function* gen() {
yield (function(x = yield) { return x; })();
}
var result = gen().next();
if (result.value !== "hello!")
throw new Error("Expected BindingIdentifier bound to 'hello!', but found " + JSON.stringify(result));
})();
testSyntax(`
function* gen() {
var ng = (it = function*() { yield 1; }) => {
return it().next();
}
yield ng();
}
`);
testSyntaxError(`
function* gen() {
var ng = (it = function() { yield 1; }) => {
return it().next();
}
yield ng();
}
`, `SyntaxError: Unexpected number '1'`);
testSyntax(`
function gen(val = yield) {
}
`);
// http://ecma-international.org/ecma-262/6.0/#sec-generator-function-definitions-static-semantics-early-errors
testSyntaxError(`
function *gen(val = yield) {
}
`, `SyntaxError: Unexpected keyword 'yield'. Cannot use yield expression within parameters.`);
testSyntaxError(`
function *gen(val = yield 20) {
}
`, `SyntaxError: Unexpected keyword 'yield'. Cannot use yield expression within parameters.`);
testSyntaxError(`
function *gen(val = yield * g) {
}
`, `SyntaxError: Unexpected keyword 'yield'. Cannot use yield expression within parameters.`);
testSyntax(`
function *gen(g = function *() { yield }) {
}
`);
testSyntaxError(`
function* gen(arguments) {
"use strict";
}
`, `SyntaxError: Invalid parameters or function name in strict mode.`);
testSyntaxError(`
function* gen(eval) {
"use strict";
}
`, `SyntaxError: Invalid parameters or function name in strict mode.`);
testSyntaxError(`
function* arguments() {
"use strict";
}
`, `SyntaxError: 'arguments' is not a valid function name in strict mode.`);
testSyntaxError(`
function* eval() {
"use strict";
}
`, `SyntaxError: 'eval' is not a valid function name in strict mode.`);
testSyntaxError(`
function* gen(a) {
let a = 1;
}
`, `SyntaxError: Cannot declare a let variable twice: 'a'.`);
testSyntaxError(`
function* gen(b) {
const b = 1;
}
`, `SyntaxError: Cannot declare a const variable twice: 'b'.`);