fix(pack): compatWebpack treeshaking config

[fireairforce]

Summary

Default value of webpack's unsedexports is true: https://webpack.js.org/configuration/optimization/#optimizationusedexports

It means even if it's undefined(user don't config), it will enable.

!!undefined === false in javascript, so in the default case utoopack will disable tree shaking(but webpack will enable).

Test Plan

[gemini-code-assist]

Summary of Changes

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This pull request resolves a critical compatibility issue within utoopack's Webpack optimization configuration. Previously, the system's boolean evaluation of undefined for usedExports inadvertently led to the disabling of tree-shaking features, contrary to Webpack's default behavior. The changes ensure that utoopack now correctly respects Webpack's default tree-shaking enablement when usedExports is not explicitly set to false, thereby improving bundle optimization.

Highlights

• Webpack Tree-shaking Compatibility Fix: Addressed an issue where utoopack incorrectly disabled Webpack's tree-shaking features (treeShaking, removeUnusedExports, removeUnusedImports) when the usedExports configuration was undefined. The logic now correctly interprets undefined as enabling these features, aligning with Webpack's default behavior.

Changelog

• packages/pack-shared/src/webpackCompat.ts
  • Introduced enableTreeShaking variable to accurately reflect Webpack's usedExports behavior.
  • Modified treeShaking, removeUnusedExports, and removeUnusedImports properties to use the new enableTreeShaking variable for correct conditional enablement.

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[gemini-code-assist]

Code Review

The pull request refactors the compatOptimization function in packages/pack-shared/src/webpackCompat.ts by introducing a new constant enableTreeShaking derived from usedExports !== false. This constant is then consistently applied to the treeShaking, removeUnusedExports, and removeUnusedImports properties, improving code readability and maintainability.

[github-actions]

📊 Performance Benchmark Report (with-antd)

Utoopack Performance Report (Intelligent)

Report ID: utoopack_performance_report_20260312_091457
Generated: 2026-03-12 09:14:57
Trace File: trace_antd.json (0.6GB, 3.31M events)
Test Project: examples/with-antd

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Executive Summary

Key Findings

Metric	Value	Assessment
Total Wall Time	8,419.8 ms	Baseline
Total Thread Work (de-duped)	27,554.5 ms	Non-overlapping busy time
Effective Parallelism	3.3x	thread_work / wall_time
Working Threads	5	Threads with actual spans
Thread Utilization	65.5%	🆗 Average
Total Spans	1,657,115	All B/E + X events
Meaningful Spans (>= 10us)	567,243	(34.2% of total)
Tracing Noise (< 10us)	1,089,872	(65.8% of total)

Workload Distribution by Tier

Category	Tasks	Total Time (ms)	% of Thread Work
P0: Runtime/Resolution	0	0.0	0.0%
P1: I/O & Heavy Tasks	39,624	3,748.5	13.6%
P3: Asset Pipeline	36,416	3,417.0	12.4%
P4: Bridge/Interop	0	0.0	0.0%
Other	491,203	22,731.8	82.5%

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🤖 AI Intelligent Attributions

New section mapping granular tasks to bottlenecks.

Top 10 Batching Candidates

These highly-called tasks are dominated by a single parent. If the parent can batch them into one call, it drastically reduces scheduler overhead.

Task Name	Count	Top Caller (Attribution)	Avg	P95	Total Time
analyze ecmascript module	36,736	process module (76%)	100.1 us	0.28 ms	3,677.7 ms

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Top 20 Tasks by Total Duration

Total (ms)	Count	Avg (us)	P95 (ms)	Max (ms)	% Work	Task Name	Top Caller
8,256.0	209,444	39.4	0.1	10.1	30.0%	module	write all entrypoints to disk (1%)
4,157.5	70,335	59.1	0.1	210.8	15.1%	process module	module (15%)
3,677.7	36,736	100.1	0.3	210.7	13.3%	analyze ecmascript module	process module (76%)
2,785.3	24,954	111.6	0.3	60.9	10.1%	code generation	chunking (6%)
1,838.8	67,364	27.3	0.0	8.4	6.7%	resolving	module (30%)
1,695.1	60,874	27.8	0.0	12.9	6.2%	internal resolving	resolving (30%)
1,372.0	14,865	92.3	0.2	47.5	5.0%	chunking	write all entrypoints to disk (0%)
1,371.3	32,470	42.2	0.1	8.7	5.0%	precompute code generation	code generation (31%)
1,157.0	8,451	136.9	0.1	224.7	4.2%	write all entrypoints to disk	None (0%)
1,137.6	13,790	82.5	0.3	140.4	4.1%	compute async module info	chunking (0%)
1,047.0	8,055	130.0	0.5	43.9	3.8%	parse ecmascript	analyze ecmascript module (26%)
635.2	11,348	56.0	0.1	44.1	2.3%	compute async chunks	compute async chunks (0%)
285.8	1,936	147.6	0.4	16.2	1.0%	generate source map	code generation (96%)
98.5	868	113.5	0.0	19.6	0.4%	compute binding usage info	write all entrypoints to disk (0%)
61.4	2,165	28.4	0.0	1.0	0.2%	read file	parse ecmascript (91%)
60.2	206	292.3	0.5	20.0	0.2%	make production chunks	chunking (2%)
49.1	1,870	26.3	0.0	8.1	0.2%	collect mergeable modules	compute merged modules (0%)
38.5	628	61.4	0.1	3.2	0.1%	async reference	write all entrypoints to disk (1%)
38.0	14	2714.7	9.2	9.7	0.1%	apply effects	write all entrypoints to disk (7%)
32.6	13	2505.1	9.2	9.7	0.1%	write file	apply effects (100%)

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Duration Distribution

Range	Count	Percentage
< 10us (noise)	1,089,872	65.8%
10us - 100us	540,859	32.6%
100us - 1ms	21,989	1.3%
1ms - 10ms	4,298	0.3%
10ms - 100ms	91	0.0%
> 100ms	6	0.0%

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Action Items

1. [P0] Use Batching Candidates to pinpoint specific files needing try_join or reduced #[turbo_tasks::function] limits.
2. [P1] Inspect P95 (ms) for heavy monolith tasks. Focus on long-tail outliers rather than averages.

Report generated by Intelligent Utoopack Performance Analysis Agent