Disallow await before exponential#12441
Merged
JLHwung merged 3 commits intobabel:mainfrom Mar 25, 2021
Merged
Conversation
JLHwung
commented
Dec 2, 2020
| export type AwaitExpression = NodeBase & { | ||
| type: "AwaitExpression", | ||
| argument: ?Expression, | ||
| argument: Expression, |
Contributor
Author
There was a problem hiding this comment.
While yield is a yield expression, await is never valid and thus the argument here can not be null.
Collaborator
|
Build successful! You can test your changes in the REPL here: https://babeljs.io/repl/build/44668/ |
|
This pull request is automatically built and testable in CodeSandbox. To see build info of the built libraries, click here or the icon next to each commit SHA. Latest deployment of this branch, based on commit 7e186f0:
|
nicolo-ribaudo
approved these changes
Dec 3, 2020
d1cf0c6 to
cadadcc
Compare
cadadcc to
7e186f0
Compare
Contributor
Author
|
✔️ (After 3 months I have completely forgotten the context of this PR) |
This was referenced Mar 29, 2021
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Babel does not throw for await before exponential:
async () => await -1 ** 1, REPL,See here for the real diff.This PR forbids await expression when it is the
leftof an exponential expression. In the first commit we refactor current check so we don't have to checknode.left.typeandextra.parenthesized, instead we check it when an AwaitExpression / UnaryExpression is parsed. Then we forbid exponential after an await is parsed.This approach is also implemented in V8 (here) and acorn (here)