v8/test/mjsunit/es6/for-each-in-catch.js

// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

function checkIsRedeclarationError(code) {
  try {
    eval(`
checkIsRedeclarationError : {
  break checkIsRedeclarationError;
${code}
}
`);
    assertUnreachable();
  } catch(e) {
    assertInstanceof(e, SyntaxError );
    assertTrue( e.toString().indexOf("has already been declared") >= 0 );
  }
}

function checkIsNotRedeclarationError(code) {
  assertDoesNotThrow(()=>eval(`
checkIsNotRedeclarationError_label : {
  break checkIsNotRedeclarationError_label;
${code}
}
`));
}


let var_e = [
  'var e',
  'var {e}',
  'var {f, e}',
  'var [e]',
  'var {f:e}',
  'var [[[], e]]'
];

let not_var_e = [
  'var f',
  'var {}',
  'var {e:f}',
  'e',
  '{e}',
  'let e',
  'const e',
  'let {e}',
  'const {e}',
  'let [e]',
  'const [e]',
  'let {f:e}',
  'const {f:e}'
];

// Check that `for (var ... of ...)` cannot redeclare a simple catch variable
// but `for (var ... in ...)` can.
for (let binding of var_e) {
  checkIsRedeclarationError(`
try {
  throw 0;
} catch(e) {
  for (${binding} of []);
}
`);

  checkIsNotRedeclarationError(`
try {
  throw 0;
} catch(e) {
  for (${binding} in []);
}
`);
}

// Check that the above error occurs even for nested catches.
for (let binding of var_e) {
  checkIsRedeclarationError(`
try {
  throw 0;
} catch(e) {
  try {
    throw 1;
  } catch(f) {
    try {
      throw 2;
    } catch({}) {
      for (${binding} of []);
    }
  }
}
`);

  checkIsNotRedeclarationError(`
try {
  throw 0;
} catch(e) {
  try {
    throw 1;
  } catch(f) {
    try {
      throw 2;
    } catch({}) {
      for (${binding} in []);
    }
  }
}
`);
}

// Check that the above error does not occur if a declaration scope is between
// the catch and the loop.
for (let binding of var_e) {
  checkIsNotRedeclarationError(`
try {
  throw 0;
} catch(e) {
  (()=>{for (${binding} of []);})();
}
`);

  checkIsNotRedeclarationError(`
try {
  throw 0;
} catch(e) {
  (function(){for (${binding} of []);})();
}
`);
}

// Check that there is no error when not declaring a var named e.
for (let binding of not_var_e) {
  checkIsNotRedeclarationError(`
try {
  throw 0;
} catch(e) {
  for (${binding} of []);
}
`);
}

// Check that there is an error for both for-in and for-of when redeclaring
// a non-simple catch parameter
for (let binding of var_e) {
  checkIsRedeclarationError(`
try {
  throw 0;
} catch({e}) {
  for (${binding} of []);
}
`);

  checkIsRedeclarationError(`
try {
  throw 0;
} catch({e}) {
  for (${binding} in []);
}
`);
}

// Check that the above error occurs even for nested catches.
for (let binding of var_e) {
  checkIsRedeclarationError(`
try {
  throw 0;
} catch({e}) {
  try {
    throw 1;
  } catch(f) {
    try {
      throw 2;
    } catch({}) {
      for (${binding} of []);
    }
  }
}
`);

  checkIsRedeclarationError(`
try {
  throw 0;
} catch({e}) {
  try {
    throw 1;
  } catch(f) {
    try {
      throw 2;
    } catch({}) {
      for (${binding} in []);
    }
  }
}
`);
}