add skipTransparentExprWrapperNodes helper

[lightmare]

Requires #13686

Q	A
Fixed Issues?	Closes #13640, this is the second half
Patch: Bug Fix?	✔️
Major: Breaking Change?	➖
Minor: New Feature?	➖
Tests Added + Pass?	amended existing
Documentation PR Link
Any Dependency Changes?
License	MIT

Description copied from #13640 :

@babel/helper-skip-transparent-expression-wrappers has a confusing interface. isTransparentExprWrapper takes a Node, while skipTransparentExprWrappers took a NodePath.
The latter was incorrectly called with a Node in @babel/plugin-proposal-optional-chaining:

babel/packages/babel-plugin-proposal-optional-chaining/src/transform.js

Line 11 in b2d9156

expression = skipTransparentExprWrappers(expression);

Consequently, optional call in loose mode produced temp variables when it shouldn't, as in this test:

babel/packages/babel-plugin-proposal-optional-chaining/test/fixtures/transparent-expr-wrappers/ts-as-function-call-loose/output.js

Line 3 in b2d9156

(_bar = ((_ref = (foo as A)).bar as B)) == null ? void 0 : _bar.call(_ref, foo.bar, false);

This PR overloads skipTransparentExprWrappers to accept either an Expression or NodePath<Expression>. This fixes the issue in @babel/plugin-proposal-optional-chaining, and also allows using the Expression overload in two other places in that plugin where the NodePath is not needed.

[babel-bot]

Build successful! You can test your changes in the REPL here: https://babeljs.io/repl/build/48309/

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[fedeci]

Hey @lightmare, can you rebase please?

[lightmare]

There's an E2E failure that seems related, it throws: Cannot read property 'isOptionalMemberExpression' of undefined

It looks like skipTransparentExprWrappers returned undefined at some point.

The only explanation I could come up with is that the expr instanceof NodePath check fails (I have no idea why, when given a path from traverse), then it goes into the else branch, where isTransparentExprWrapper(expr) succeeds because it effectively checks expr.type and NodePath happens to have a .type member, and then expr.expression is returned, which NodePath doesn't have.

But it's weird, this is not the only place where instanceof NodePath is used.

[JLHwung]

The expr instanceof NodePath check may fail when there are multiple copies of @babel/traverse in node modules and some of them are depended by different packages. We have seen similar issues in the past: #11734

[lightmare]

Thank you for the explanation. I guess the best solution will be to add a separate method instead of overloading.

[lightmare]

I have reverted the overload patch, and pushed a new version with a separate function.
When it's okay, I will squash the commits so that the reverted patch doesn't clutter history.

[fedeci]

Didn't we "recently" merged another helper with instanceof NodePath in its body?

[lightmare]

Should I squash the commits in the branch, or will you just squash it during merge?

[JLHwung]

@lightmare We use Squash and merge most of time. So you are all set.