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Diffstat (limited to 'js/src/tests/test262/annexB/language/expressions/yield/star-iterable-return-emulates-undefined-throws-when-called.js')
-rw-r--r-- | js/src/tests/test262/annexB/language/expressions/yield/star-iterable-return-emulates-undefined-throws-when-called.js | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/js/src/tests/test262/annexB/language/expressions/yield/star-iterable-return-emulates-undefined-throws-when-called.js b/js/src/tests/test262/annexB/language/expressions/yield/star-iterable-return-emulates-undefined-throws-when-called.js new file mode 100644 index 0000000000..c424651c61 --- /dev/null +++ b/js/src/tests/test262/annexB/language/expressions/yield/star-iterable-return-emulates-undefined-throws-when-called.js @@ -0,0 +1,33 @@ +// Copyright (C) 2017 Mozilla Corporation. All rights reserved. +// This code is governed by the BSD license found in the LICENSE file. + +/*--- +esid: sec-generator-function-definitions-runtime-semantics-evaluation +description: > + If <iterator>.return is an object emulating `undefined` (e.g. `document.all` + in browsers), it shouldn't be treated as if it were actually `undefined` by + the yield* operator. +features: [generators, IsHTMLDDA] +---*/ + +var IsHTMLDDA = $262.IsHTMLDDA; +var iter = { + [Symbol.iterator]() { return this; }, + next() { return {}; }, + return: IsHTMLDDA, +}; + +var outer = (function*() { yield* iter; })(); + +outer.next(); + +assert.throws(TypeError, function() { + // `IsHTMLDDA` is called here with `iter` as `this` and `emptyString` as the + // sole argument, and it's specified to return `null` under these conditions. + // As `iter`'s iteration isn't ending because of a throw, the iteration + // protocol will then throw a `TypeError` because `null` isn't an object. + var emptyString = ""; + outer.return(emptyString); +}); + +reportCompare(0, 0); |