feat(formatter): Detect code removal feature #15059

leaysgur · 2025-10-29T07:40:12Z

Part of #13720

Introduce detect_code_removal feature flag
If enabled, Formatter::format() performs extra check
- Currently, every public API calls format()
Code removal detection consists of the following two steps:
- bf = collect(original_text) and af = collect(formatted_text)
- diff(bf, af)
Basically, this works by counting node.debug_name()
- Some AST nodes are ignored due to difficulty

NOTE: The feature has been added but is not yet enabled anywhere.

Enable feature somewhere
- tasks/prettier_conformance
- tasks/coverage
- tasks/benchmark
- crates/oxc_formatter
- crates/oxc_language_server
- apps/oxfmt
- napi/playground
- monitor-oxc
- oxlint-ecosystem-ci
This feature should be enabled by default and should be opt-out, or explicitly enabled?

leaysgur · 2025-10-29T07:40:31Z

feat(formatter): Detect code removal feature #15059 👈 (View in Graphite)
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Pull Request Overview

This PR adds a code removal detection feature to the formatter to help identify cases where formatting might inadvertently remove code. The feature is gated behind a detect_code_removal feature flag and can be used during development to detect potential formatting bugs.

Key changes:

Adds a new detect_code_removal module that performs pre- and post-formatting AST analysis
Updates the formatter to optionally run code removal detection and report findings via stderr
Adds feature flag support for the optional detection mechanism

Reviewed Changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
crates/oxc_formatter/src/lib.rs	Integrates the code removal detection logic into the formatting pipeline when the feature flag is enabled
crates/oxc_formatter/src/detect_code_removal/mod.rs	Implements the complete code removal detection logic including AST node counting, comment tracking, and diff reporting
crates/oxc_formatter/Cargo.toml	Adds optional dependencies and feature flag for code removal detection
crates/oxc_ast/src/ast_kind_impl.rs	Updates documentation for the `debug_name` method
Cargo.lock	Reflects the addition of new dependencies

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crates/oxc_formatter/Cargo.toml

crates/oxc_formatter/src/detect_code_removal/mod.rs

crates/oxc_formatter/src/lib.rs

codspeed-hq · 2025-10-29T07:50:20Z

CodSpeed Performance Report

Merging #15059 will not alter performance

_{Comparing 10-23-feat_formatter_detect_code_removal_feature (a5ac520) with main (59bb65c)¹}

Summary

✅ 37 untouched

No successful run was found on main (1bf9ef1) during the generation of this report, so 59bb65c was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

Boshen · 2025-10-29T08:32:37Z

Enable feature somewhere

Let's start from oxlint-ecosystem-ci and oxc-monitor.

I'll change oxlint-ecosystem-ci to oxc-ecosystem-ci at some point.

Dunqing · 2025-10-30T07:01:09Z

Leaves oxlint-ecosystem-ci to me, I am making some changes to it.

leaysgur · 2025-10-30T07:11:12Z

Leaves oxlint-ecosystem-ci to me

Thank you~!
👉🏻 #13720 (comment)

crates/oxc_formatter/src/lib.rs

Copilot · 2025-10-30T07:20:37Z

@Dunqing I've opened a new pull request, #15114, to work on those changes. Once the pull request is ready, I'll request review from you.

crates/oxc_formatter/src/lib.rs

Dunqing · 2025-10-31T00:47:21Z

Merge activity

Oct 31, 12:47 AM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
Oct 31, 12:47 AM UTC: Dunqing added this pull request to the Graphite merge queue.
Oct 31, 12:53 AM UTC: Merged by the Graphite merge queue.

Part of #13720 - Introduce `detect_code_removal` feature flag - If enabled, `Formatter::format()` performs extra check - Currently, every public API calls `format()` - Code removal detection consists of the following two steps: - `bf = collect(original_text)` and `af = collect(formatted_text)` - `diff(bf, af)` - Basically, this works by counting `node.debug_name()` - Some AST nodes are ignored due to difficulty NOTE: The feature has been added but is not yet enabled anywhere. --- - Enable feature somewhere - tasks/prettier_conformance - tasks/coverage - tasks/benchmark - crates/oxc_formatter - crates/oxc_language_server - apps/oxfmt - napi/playground - monitor-oxc - oxlint-ecosystem-ci - This feature should be enabled by default and should be opt-out, or explicitly enabled?

## [0.10.0] - 2025-11-04 ### 🚀 Features - 505252c formatter: Wrap parenthesis for AssignmentExpression that is a key of `PropertyDefinition` (#15243) (Dunqing) - 880b259 formatter: Align import-like formatting the same as Prettier (#15238) (Dunqing) - b77f254 oxfmt,formatter: Support `embeddedLanguageFormatting` option (#15216) (leaysgur) - 898d6fe oxfmt: Add embedded language formatting with Prettier integration (#14820) (Boshen) - e77a48e formatter: Detect code removal feature (#15059) (leaysgur) ### 🐛 Bug Fixes - daacf85 oxfmt: Release build fails (#15262) (Dunqing) - f5d0348 oxfmt: Sync `dependencies` with `npm/oxfmt` and `apps/oxfmt` (#15261) (leaysgur) - 46793d7 formatter: Correct printing comments for `LabeledStatement` (#15260) (Dunqing) - 831ae99 formatter: Multiple comments in `LogicalExpression` and `TSIntersectionType` (#15253) (Dunqing) - 5fa9b1e formatter: Should not indent `BinaryLikeExpression` when it is an argument of `Boolean` (#15250) (Dunqing) - 99e520f formatter: Handle chain expression for `JSXExpressionContainer` (#15242) (Dunqing) - a600bf5 formatter: Correct printing comments for `TaggedTemplateExpression` (#15241) (Dunqing) - a7289e7 formatter: Handle member chain for the call's parent is a chain expression (#15237) (Dunqing) ### 🚜 Refactor - 36ae721 formatter: Simplify the use of `indent` with `soft_line_break_or_space` (#15254) (Dunqing) - cdd8e2f formatter/sort-imports: Split sort_imports modules (#15189) (leaysgur) - 27b4f36 diagnostic: Remove `path` from sender (#15130) (camc314) - 85fb8e8 formatter/sort-imports: Pass options to is_ignored() (#15181) (leaysgur) ### 🧪 Testing - 9d5b34b formatter/sort-imports: Refactor sort_imports tests (#15188) (leaysgur) Co-authored-by: leaysgur <[email protected]>

Copilot AI review requested due to automatic review settings October 29, 2025 07:40

leaysgur requested a review from Dunqing as a code owner October 29, 2025 07:40

github-actions bot added A-ast Area - AST A-formatter Area - Formatter C-enhancement Category - New feature or request labels Oct 29, 2025

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leaysgur force-pushed the 10-23-feat_formatter_detect_code_removal_feature branch 2 times, most recently from 252be4c to 4927e88 Compare October 29, 2025 08:26

leaysgur force-pushed the 10-23-feat_formatter_detect_code_removal_feature branch from 4927e88 to a72cf8e Compare October 30, 2025 06:26

leaysgur mentioned this pull request Oct 30, 2025

formatter: infra to detect no code removal #13720

Open

leaysgur assigned Dunqing Oct 30, 2025

leaysgur mentioned this pull request Oct 30, 2025

Add formatter detect_code_removal runner oxc-project/monitor-oxc#118

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Dunqing reviewed Oct 30, 2025

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Copilot AI mentioned this pull request Oct 30, 2025

[WIP] WIP address feedback on code removal detection feature #15114

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leaysgur force-pushed the 10-23-feat_formatter_detect_code_removal_feature branch from a72cf8e to ee017a3 Compare October 30, 2025 08:21

leaysgur commented Oct 30, 2025

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leaysgur force-pushed the 10-23-feat_formatter_detect_code_removal_feature branch from 5c7af27 to a5ac520 Compare October 30, 2025 09:34

leaysgur requested a review from Dunqing October 30, 2025 09:36

Dunqing approved these changes Oct 31, 2025

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Dunqing added the 0-merge Merge with Graphite Merge Queue label Oct 31, 2025

graphite-app bot force-pushed the 10-23-feat_formatter_detect_code_removal_feature branch from a5ac520 to e77a48e Compare October 31, 2025 00:47

graphite-app bot merged commit e77a48e into main Oct 31, 2025
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graphite-app bot deleted the 10-23-feat_formatter_detect_code_removal_feature branch October 31, 2025 00:53

graphite-app bot removed the 0-merge Merge with Graphite Merge Queue label Oct 31, 2025

Boshen mentioned this pull request Nov 4, 2025

release(oxfmt): v0.10.0 #15263

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