Remove disabled optional weak dependencies when resolving

[Jackhr-arch]

What does this PR try to resolve?

it changes the parts of the resolver that generate Cargo.lock to not include weak dependencies.

Instead of treating weak feature as strong one, now resolver keeps the weak dependency features until the very dependency is checked. Then it combines the weak features with the original ones.

Related to #10801

How to test and review this PR?

I've enabled some tests in crates/resolver-tests relating to Weak dependencies and looks they work fine.

Here is an example repo https://github.com/Jackhr-arch/cargo-weak-dep-feat-example

[rustbot]

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[epage]

I won't be up for reviewing the core part of this, so my comments are a pre-review.

Please clean up commits for how they should be reviewed and merged.

r? @Eh2406

[est31]

I haven't done a review of the approach, I wonder whether this supports the weak_namespaced_v4 test from my earlier PR, or if it fails similarly (see ehuss comment and discussion immediately below).

[Jackhr-arch]

I wonder whether this supports the weak_namespaced_v4 test from my earlier PR

It passed. I port 4 tests from your pull request, and deferred_v5 failed. I'm trying to fix this.

EDIT: it's now done.

[rustbot]

This PR was rebased onto a different master commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[epage]

Please clean up commits for how they should be reviewed and merged.

Thank you for cleaning up your commits!

btw something we've found helpful is to add all tests in one or more commits before the fix, with them passing (showing the existing behavior). The commit that introduces the change then updates the test. The diff of the commits then helps to show how behavior changed. See https://doc.crates.io/contrib/process/working-on-cargo.html#submitting-a-pull-request

[epage]

Note that we expect commits to be atomic which includes tests are passing. Please squash the test update commits into the associated feature work commit.

[epage]

I'd recommend following the existing testing patterns, rather than creating new ones. We tend to use snapshot tests of the complete output.

[Jackhr-arch]

Weak dependency feature related packages usually only appear in Cargo.lock and [Downloading], cargo tree or cargo check won't show they are here or not, thus I read Cargo.lock.

Anyway, I've changed to snapshot.