Suggest async when await is followed by arrow function.
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Attempts to fix issue #279. Excluded the cases where `await` is followed by an `async` then followed by an arrow function. In this case `await` must be an unary operator. This commit does not solve issue #278 just yet, but should be a start. Here the error is only caught for top-level await and async function, i.e cases where async is *not* treated as an identifier.
Will squash it latter.
It's done by checking if there is a arrow function after `await` even if its treated as an identifier. There is some code duplication between this commit and the earlier one so I will try to work out a way to combine these two. Also, I don't know enough JS to know if the tests are strict enough to catch all the cases.
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Should be good for review. |
strager
requested changes
May 19, 2021
| @@ -869,6 +869,64 @@ TEST_F(test_parse_expression, await_unary_operator_inside_async_functions) { | |||
| EXPECT_EQ(summarize(ast), "await(var x)"); | |||
| EXPECT_THAT(p.errors(), IsEmpty()); | |||
| } | |||
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| { | |||
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Nit: I think these new tests belong in a different TEST_F than test_parse_expression.await_unary_operator_inside_async_functions. For example, the test on line 899 is for a normal (non-async) function, which is definitely not what the test's name implies.
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| EXPECT_EQ(ast->kind(), expression_kind::binary_operator); | ||
| EXPECT_THAT( | ||
| p.errors(), | ||
| ElementsAre( | ||
| ERROR_TYPE_FIELD(error_await_creating_arrow_function, | ||
| await_operator, | ||
| offsets_matcher(p.code(), 0, u8"await")), | ||
| ERROR_TYPE_FIELD( | ||
| error_missing_operator_between_expression_and_arrow_function, | ||
| where, offsets_matcher(p.code(), 0, u8"await (")))); |
| if (child->kind() == expression_kind::_invalid) { | ||
| this->error_reporter_->report(error_missing_operand_for_operator{ | ||
| .where = operator_span, | ||
| }); | ||
| } | ||
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| @@ -715,6 +715,30 @@ expression* parser::parse_await_expression(token await_token, precedence prec) { | |||
| } | |||
| }(); | |||
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| if (this->peek().type == token_type::left_paren) { | |||
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This code fails to catch arrow functions which don't have parentheses around the parameter list. For example:
await x => {}See my comment on line 760 for a possible solution.
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Attempts to fix issues #279 and #278.
In both cases we can check if
await (is followed by an arrow function, suggest changing it toasyncand then rollback.For the expression beginning with
await (inside anasyncfunction the expression following it is parsed twice, this happens because we have no way to know beforehand if we want that expression to be parsed andawaitmight be an identifier or something else.