Skip to content

Improve transform-destructuring typings#14236

Merged
JLHwung merged 8 commits intobabel:mainfrom
JLHwung:improve-destructuring-typings
Mar 7, 2022
Merged

Improve transform-destructuring typings#14236
JLHwung merged 8 commits intobabel:mainfrom
JLHwung:improve-destructuring-typings

Conversation

@JLHwung
Copy link
Copy Markdown
Contributor

@JLHwung JLHwung commented Feb 3, 2022

Q                       A
License MIT

This PR improves typings of plugin-transform-destructuring. I extracted these routines into a new module.

  • DestructuringTransformer
  • convertVariableDeclaration
  • convertAssignmentExpression

They are likely to be reused in the destructuring-private transformer I am currently working on. In this PR they are not exposed so it can ship in patch release.


if (
t.isIdentifier(node) &&
t.isReferenced(node, ancestors[ancestors.length - 1]) &&
Copy link
Copy Markdown
Contributor Author

@JLHwung JLHwung Feb 3, 2022

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

t.isReferenced(node, ancestors[ancestors.length - 1]) is changed to t.isReferenced(node, ancestors[ancestors.length - 1].node). This is a bug caught by type checker.

const specifiers = [];

for (const name of Object.keys(path.getOuterBindingIdentifiers(path))) {
for (const name of Object.keys(path.getOuterBindingIdentifiers())) {
Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Another bug caught by type checker.

@babel-bot
Copy link
Copy Markdown
Collaborator

babel-bot commented Feb 3, 2022

Build successful! You can test your changes in the REPL here: https://babeljs.io/repl/build/51391/

path.ensureBlock();

const block = node.body;
// @ts-expect-error: ensureBlock ensures that node.body is a BlockStatement
Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Could you check if changing the ensureBlock signature to this helps?

function ensureBlock<T extends  t.Loop | t.WithStatement | t.Function | t.LabeledStatement | t.CatchClause>(
  this: NodePath<T>,
): assert this is NodePath<T & { node: t.BlockStatement }>

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Unfortunately we can't add type assertion without breaking change because:

  1. ensureBlock returns a t.Node while assertion predicates requires that the function returns void.
  2. this-type guards can only be added to a class method, though we can move it back to index or put it in a separate file and extends an interface (type with assertions) instead.

Comment on lines +11 to +16
for (const elem of pattern.elements) {
if (t.isRestElement(elem)) {
return true;
}
}
return false;
Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Nit: these could be "compacted" to pattern.elements.some(elem => t.isRestElement(elem))

@JLHwung JLHwung force-pushed the improve-destructuring-typings branch 2 times, most recently from 527552b to 57535de Compare February 11, 2022 21:29
@JLHwung JLHwung force-pushed the improve-destructuring-typings branch 2 times, most recently from c309266 to 446b07e Compare February 23, 2022 19:02
@JLHwung JLHwung force-pushed the improve-destructuring-typings branch from 446b07e to 85697cf Compare February 28, 2022 19:43
@existentialism existentialism added the PR: Internal 🏠 A type of pull request used for our changelog categories label Mar 7, 2022
@JLHwung JLHwung merged commit 4f80f5c into babel:main Mar 7, 2022
@JLHwung JLHwung deleted the improve-destructuring-typings branch March 7, 2022 21:14
@github-actions github-actions bot added the outdated A closed issue/PR that is archived due to age. Recommended to make a new issue label Jun 7, 2022
@github-actions github-actions bot locked as resolved and limited conversation to collaborators Jun 7, 2022
Sign up for free to subscribe to this conversation on GitHub. Already have an account? Sign in.

Labels

outdated A closed issue/PR that is archived due to age. Recommended to make a new issue PR: Internal 🏠 A type of pull request used for our changelog categories

Projects

None yet

Development

Successfully merging this pull request may close these issues.

4 participants