chore(rust): MSRV 1.88.0

[Boshen]

This broke the linter ast nodes detector

[graphite-app]

How to use the Graphite Merge Queue

Add either label to this PR to merge it via the merge queue:

• 0-merge - adds this PR to the back of the merge queue
• hotfix - for urgent hot fixes, skip the queue and merge this PR next

You must have a Graphite account in order to use the merge queue. Sign up using this link.

An organization admin has enabled the Graphite Merge Queue in this repository.

Please do not merge from GitHub as this will restart CI on PRs being processed by the merge queue.

[Copilot]

Pull Request Overview

This PR updates the minimum supported Rust version (MSRV) to 1.88.0 and utilizes the new let-chains syntax feature that became stable in this version. The changes systematically replace nested if let statements with the more concise let-chains syntax throughout the codebase.

• Updates MSRV to Rust 1.88.0 to enable let-chains syntax
• Refactors nested conditional patterns to use let-chains for improved readability
• Maintains the same logic while reducing code complexity and nesting levels

Reviewed Changes

Copilot reviewed 277 out of 277 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
crates/oxc_transformer_plugins/src/replace_global_defines.rs	Simplified nested if-let pattern in expression matching
crates/oxc_transformer/src/typescript/module.rs	Combined multiple conditions using let-chains in declaration handling
crates/oxc_transformer/src/typescript/class.rs	Refactored class field processing with let-chains
crates/oxc_transformer/src/plugins/styled_components.rs	Simplified conditional checks in styled components processing
crates/oxc_transformer/src/options/babel/mod.rs	Combined option checking logic using let-chains
Multiple other files	Similar refactoring patterns applying let-chains syntax throughout the codebase

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #13977 will not alter performance

_{Comparing 09-21-chore_rust_msrv_1.88.0-2 (c778cba) with main (4ee94a3)¹}

Summary

✅ 37 untouched

Footnotes

1. No successful run was found on main (c778cba) during the generation of this report, so 4ee94a3 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[Dunqing]

If possible, I hope this stack of #13928 is merged first, as every PR in that stack may lead to conflicts with this PR.

[Sysix]

oxc_language_server: ✔️

[camchenry]

@Boshen I think we just need to run cargo lintgen? The syntax has changed slightly so some rules have reverted to a more conservative behavior, but we can fix that in a separate PR

[camc314]

• chore(rust): MSRV 1.88.0 #13977 👈 (View in Graphite)
• main

---

How to use the Graphite Merge Queue

Add either label to this PR to merge it via the merge queue:

• 0-merge - adds this PR to the back of the merge queue
• hotfix - for urgent hot fixes, skip the queue and merge this PR next

You must have a Graphite account in order to use the merge queue. Sign up using this link.

An organization admin has enabled the Graphite Merge Queue in this repository.

Please do not merge from GitHub as this will restart CI on PRs being processed by the merge queue.

This stack of pull requests is managed by Graphite. Learn more about stacking.

[camc314]

i reran lintgen, some nodes changes from Some(AstTypesBitset) to none as our codegen isn't detecing if let AstKind::X = node.kind() && ..., but we can fix that in a followup

[camc314]

If possible, I hope this stack of #13928 is merged first, as every PR in that stack may lead to conflicts with this PR.

@Dunqing lets merge that stack first, then i'll rebase this one

[camc314]

Merge activity

• Sep 22, 7:48 AM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Sep 22, 2:04 PM UTC: camc314 added this pull request to the Graphite merge queue.
• Sep 22, 2:09 PM UTC: Merged by the Graphite merge queue.