Ditch nodeData interface in favor of generated accessors

[Jake Bailey (jakebailey)]

This ditches the dynamic dispatch with nodeData in place of generated kind switches, like I did with ForEachChild.

Metric	Merge base	Branch	Change
Binary file	24,658,183 B	23,810,311 B	-847,872 B (-3.44%)
Executable .text	9,491,153 B	9,369,617 B	-121,536 B (-1.28%)
Go PC/line metadata .gopclntab	9,280,667 B	8,584,857 B	-695,810 B (-7.50%)
Go type metadata .go.type	3,447,248 B	3,404,384 B	-42,864 B (-1.24%)
Total allocated sections	24,889,742 B	24,042,436 B	-847,306 B (-3.40%)

Metric	Merge base	Branch	Change
Symbols containing tsc/internal/ast	6,331	2,673	-3,658 (-57.78%)
AST pointer-receiver methods	5,477	1,819	-3,658 (-66.79%)

It also makes compiling the ast package 5% faster.

[Jake Bailey (jakebailey)]

TypeScript Bot (@typescript-bot) perf test this

[typescript-automation]

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
perf test this	✅ Started	👀 Results

[Copilot]

Pull request overview

Replaces nodeData interface dispatch with generated kind-based AST accessors to reduce binary size and metadata overhead.

Changes:

• Generates AST visitor, clone, subtree-fact, and accessor dispatch.
• Updates compiler and language-service consumers for the new representation.
• Adds canonical token-payload validation and adjusts direct node construction.

Reviewed changes

Copilot reviewed 23 out of 25 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tools/scripts/tsc/generate-go-ast.ts	Generates kind-based AST dispatch.
tools/scripts/tsc/generate-encoder.ts	Updates generated private-field access.
tsc/internal/ast/ast.go	Reworks node storage and common fields.
tsc/internal/ast/ast_generated.go	Contains generated factories and dispatch.
tsc/internal/ast/flow.go	Adapts synthetic flow-node construction.
tsc/internal/ast/token_test.go	Tests canonical token payloads.
tsc/internal/ast/utilities.go	Updates type-only checks.
tsc/internal/api/encoder/encoder.go	Updates source-file position access.
tsc/internal/api/encoder/encoder_generated.go	Updates generated text access.
tsc/internal/checker/grammarchecks.go	Uses common node accessors.
tsc/internal/checker/nodebuilder_hover.go	Updates optional-token access.
tsc/internal/ls/autoimport/fix.go	Updates type-only import access.
tsc/internal/ls/completions.go	Updates source-file access.
tsc/internal/ls/lsutil/organizeimports.go	Updates import classification.
tsc/internal/ls/organizeimports.go	Updates type-only grouping.
tsc/internal/ls/signaturehelp.go	Updates type-argument access.
tsc/internal/parser/reparser.go	Updates mutable typed-node casts.
tsc/internal/printer/printer_test.go	Adapts transformed source-file casts.
tsc/internal/scanner/scanner_test.go	Adapts node initialization.
tsc/internal/transformers/declarations/transform.go	Updates syntax-list traversal.
tsc/internal/transformers/estransforms/optionalchain.go	Updates element-access casting.
tsc/internal/transformers/moduletransforms/commonjsmodule.go	Updates common expression/name access.
tsc/internal/transformers/tstransforms/legacydecorators.go	Updates decorator access.
tsc/internal/transformers/tstransforms/runtimesyntax.go	Updates parameter-list access.
tsc/internal/transformers/tstransforms/typeeraser.go	Updates type-only import access.

Files not reviewed (1)

• tsc/internal/api/encoder/encoder_generated.go: Generated file

Suppressed comments (1)

tsc/internal/ast/flow.go:74

• This node likewise stores *FlowReduceLabelData under KindUnknown, while the generated Clone and subtree-facts switches assert that every KindUnknown payload is *Token. Those methods now panic for reduce-label nodes; previously dynamic dispatch reached NodeDefault. Use a distinct kind or explicitly handle this synthetic payload in dispatch, with a regression test.

	return newNode(KindUnknown, node.AsNode(), node, NodeFactoryHooks{})

[typescript-automation]

Jake Bailey (@jakebailey)
The results of the perf run you requested are in!

Here they are:

tsc

Comparison Report - baseline..pr

Metric	baseline	pr	Delta	Best	Worst	p-value
Compiler-Unions - native
Errors	41	41	~	~	~	p=1.000 n=12
Symbols	115,480	115,480	~	~	~	p=1.000 n=12
Types	96,945	96,945	~	~	~	p=1.000 n=12
Memory Used	148,704k (± 0.63%)	148,990k (± 0.61%)	~	146,603k	150,783k	p=0.619 n=12
Memory Allocs	2,271,343 (± 0.00%)	2,271,370 (± 0.01%)	~	2,271,042	2,271,725	p=0.799 n=12
Config Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Parse Time	0.050s (± 3.10%)	0.049s (± 2.83%)	~	0.046s	0.053s	p=0.525 n=12
Bind Time	0.016s (±13.70%)	0.017s (±12.12%)	~	0.013s	0.022s	p=0.462 n=12
Check Time	0.593s (± 0.79%)	0.602s (± 0.99%)	+0.009s (+ 1.50%)	0.592s	0.618s	p=0.016 n=12
Emit Time	0.331s (± 2.03%)	0.338s (± 1.95%)	~	0.322s	0.356s	p=0.096 n=12
Total Time	0.997s (± 1.07%)	1.013s (± 0.89%)	+0.016s (+ 1.62%)	0.993s	1.038s	p=0.011 n=12
angular-1 - native
Errors	3	3	~	~	~	p=1.000 n=12
Symbols	847,457 (± 0.08%)	847,042 (± 0.06%)	~	845,864	848,120	p=0.242 n=12
Types	249,852 (± 0.00%)	249,853 (± 0.00%)	~	249,849	249,862	p=0.497 n=12
Memory Used	793,348k (± 0.05%)	793,428k (± 0.06%)	~	791,771k	794,529k	p=0.410 n=12
Memory Allocs	12,951,967 (± 0.02%)	12,954,725 (± 0.04%)	~	12,948,861	12,981,625	p=0.319 n=12
Config Time	0.020s	0.022s (± 5.61%)	🔻+0.002s (+ 9.17%)	0.020s	0.024s	p=0.005 n=12
Parse Time	0.348s (± 2.62%)	0.358s (± 2.93%)	~	0.331s	0.382s	p=0.213 n=12
Bind Time	0.079s (±10.71%)	0.079s (± 1.48%)	+0.000s (+ 0.42%)	0.077s	0.084s	p=0.014 n=12
Check Time	0s	0s	~	~	~	p=1.000 n=12
Emit Time	1.964s (± 1.37%)	2.067s (± 1.06%)	🔻+0.103s (+ 5.23%)	2.020s	2.117s	p=0.000 n=12
Total Time	2.430s (± 1.24%)	2.544s (± 1.07%)	🔻+0.114s (+ 4.68%)	2.491s	2.619s	p=0.000 n=12
mui-docs - native
Errors	11,277 (± 0.03%)	11,274 (± 0.05%)	~	11,256	11,281	p=0.656 n=12
Symbols	4,268,528	4,268,528	~	~	~	p=1.000 n=12
Types	1,593,260	1,593,260	~	~	~	p=1.000 n=12
Memory Used	4,727,424k (± 0.04%)	4,726,863k (± 0.04%)	~	4,722,770k	4,733,595k	p=0.514 n=12
Memory Allocs	47,631,206 (± 0.03%)	47,634,270 (± 0.05%)	~	47,568,063	47,703,849	p=0.977 n=12
Config Time	0.019s (± 1.60%)	0.019s (± 1.60%)	~	0.019s	0.020s	p=1.000 n=12
Parse Time	0.679s (± 2.38%)	0.686s (± 1.47%)	~	0.655s	0.706s	p=0.451 n=12
Bind Time	0.002s (±12.64%)	0.002s (±13.40%)	~	0.002s	0.003s	p=0.667 n=12
Check Time	19.824s (± 0.54%)	19.921s (± 0.51%)	~	19.751s	20.285s	p=0.071 n=12
Emit Time	0.556s (±14.37%)	0.517s (± 0.44%)	~	0.512s	0.524s	p=0.053 n=12
Total Time	22.005s (± 0.72%)	22.063s (± 0.55%)	~	21.839s	22.492s	p=0.443 n=12
strada-build-src - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	1,394,252	1,394,252	~	~	~	p=1.000 n=12
Types	443,418	443,418	~	~	~	p=1.000 n=12
Memory Used	1,644,285k (± 0.19%)	1,644,608k (± 0.21%)	~	1,632,450k	1,651,134k	p=0.630 n=12
Memory Allocs	97,050,478 (± 0.03%)	97,054,471 (± 0.03%)	~	96,986,967	97,119,845	p=0.932 n=12
Config Time	0.006s (±11.44%)	0.005s (±16.17%)	~	0.002s	0.007s	p=0.971 n=12
Parse Time	0.236s (± 2.51%)	0.235s (± 2.67%)	~	0.218s	0.247s	p=0.921 n=12
Bind Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Check Time	2.158s (± 0.34%)	2.193s (± 0.55%)	+0.036s (+ 1.67%)	2.159s	2.224s	p=0.000 n=12
Emit Time	0.328s (± 3.83%)	0.335s (± 6.32%)	~	0.290s	0.391s	p=0.788 n=12
Total Time	29.760s (± 0.46%)	30.237s (± 0.55%)	+0.477s (+ 1.60%)	29.761s	30.659s	p=0.000 n=12
strada-compiler - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	337,531	337,531	~	~	~	p=1.000 n=12
Types	198,830	198,830	~	~	~	p=1.000 n=12
Memory Used	319,525k (± 0.03%)	319,545k (± 0.02%)	~	319,381k	319,705k	p=0.713 n=12
Memory Allocs	4,672,822 (± 0.01%)	4,672,757 (± 0.01%)	~	4,671,682	4,673,967	p=0.590 n=12
Config Time	0.001s	0.001s	~	~	~	p=1.000 n=12
Parse Time	0.112s (± 5.15%)	0.113s (± 4.16%)	~	0.097s	0.123s	p=0.680 n=12
Bind Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Check Time	1.039s (± 0.58%)	1.057s (± 0.52%)	+0.019s (+ 1.79%)	1.044s	1.076s	p=0.000 n=12
Emit Time	0.131s (±13.99%)	0.142s (±10.03%)	~	0.104s	0.167s	p=0.417 n=12
Total Time	1.341s (± 0.99%)	1.366s (± 0.98%)	+0.024s (+ 1.81%)	1.329s	1.398s	p=0.016 n=12
ts-pre-modules - native
Errors	87	87	~	~	~	p=1.000 n=12
Symbols	305,179	305,179	~	~	~	p=1.000 n=12
Types	181,876	181,876	~	~	~	p=1.000 n=12
Memory Used	277,177k (± 0.02%)	277,249k (± 0.02%)	~	277,119k	277,401k	p=0.058 n=12
Memory Allocs	1,641,802 (± 0.01%)	1,641,776 (± 0.01%)	~	1,641,330	1,642,158	p=0.977 n=12
Config Time	0.000s	0.000s (±217.90%)	~	0.000s	0.001s	p=1.000 n=12
Parse Time	0.098s (± 4.32%)	0.101s (± 1.97%)	+0.003s (+ 3.06%)	0.094s	0.107s	p=0.027 n=12
Bind Time	0.039s (±11.25%)	0.040s (±10.20%)	~	0.033s	0.054s	p=0.432 n=12
Check Time	0.831s (± 0.67%)	0.846s (± 0.38%)	+0.015s (+ 1.79%)	0.838s	0.855s	p=0.000 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	0.983s (± 0.91%)	1.001s (± 0.42%)	+0.019s (+ 1.92%)	0.991s	1.013s	p=0.001 n=12
vscode - native
Errors	347	347	~	~	~	p=1.000 n=12
Symbols	8,099,608	8,099,608	~	~	~	p=1.000 n=12
Types	2,787,191	2,787,191	~	~	~	p=1.000 n=12
Memory Used	5,473,265k (± 0.02%)	5,473,514k (± 0.03%)	~	5,470,222k	5,479,175k	p=0.799 n=12
Memory Allocs	42,145,509 (± 0.04%)	42,141,955 (± 0.04%)	~	42,120,291	42,208,283	p=0.843 n=12
Config Time	0.064s (± 0.51%)	0.064s (± 0.28%)	~	0.063s	0.064s	p=1.000 n=12
Parse Time	1.672s (± 1.61%)	1.598s (± 3.19%)	🟩-0.074s (- 4.42%)	1.469s	1.691s	p=0.015 n=12
Bind Time	0.351s (± 2.84%)	0.432s (±19.96%)	🔻+0.081s (+23.13%)	0.354s	0.692s	p=0.000 n=12
Check Time	10.073s (± 0.87%)	10.107s (± 1.63%)	~	9.712s	10.376s	p=0.630 n=12
Emit Time	3.226s (± 5.89%)	3.789s (±13.24%)	🔻+0.563s (+17.46%)	3.103s	5.028s	p=0.006 n=12
Total Time	15.475s (± 0.75%)	16.084s (± 2.40%)	+0.608s (+ 3.93%)	15.409s	17.070s	p=0.000 n=12
webpack - native
Errors	538	538	~	~	~	p=1.000 n=12
Symbols	857,681	857,681	~	~	~	p=1.000 n=12
Types	394,496	394,496	~	~	~	p=1.000 n=12
Memory Used	656,000k (± 0.02%)	656,131k (± 0.03%)	~	655,790k	656,556k	p=0.266 n=12
Memory Allocs	4,378,603 (± 0.04%)	4,376,261 (± 0.02%)	-2,342 (- 0.05%)	4,374,294	4,379,723	p=0.045 n=12
Config Time	0.007s	0.007s	~	~	~	p=1.000 n=12
Parse Time	0.173s (± 1.29%)	0.168s (± 3.73%)	~	0.147s	0.182s	p=0.102 n=12
Bind Time	0.033s (± 2.54%)	0.041s (±19.61%)	🔻+0.008s (+23.12%)	0.033s	0.069s	p=0.012 n=12
Check Time	1.143s (± 0.65%)	1.158s (± 0.95%)	+0.015s (+ 1.33%)	1.122s	1.173s	p=0.005 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	1.375s (± 0.43%)	1.394s (± 0.73%)	+0.019s (+ 1.37%)	1.364s	1.420s	p=0.002 n=12
xstate-main - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	1,022,487	1,022,487	~	~	~	p=1.000 n=12
Types	376,962	376,962	~	~	~	p=1.000 n=12
Memory Used	603,384k (± 0.02%)	603,441k (± 0.01%)	~	603,289k	603,638k	p=0.755 n=12
Memory Allocs	4,754,818 (± 0.04%)	4,755,010 (± 0.04%)	~	4,750,794	4,759,753	p=0.799 n=12
Config Time	0.002s	0.002s	~	~	~	p=1.000 n=12
Parse Time	0.117s (± 3.29%)	0.116s (± 4.46%)	~	0.106s	0.132s	p=0.722 n=12
Bind Time	0.035s (±20.33%)	0.035s (±17.12%)	~	0.026s	0.056s	p=0.394 n=12
Check Time	0.853s (± 0.67%)	0.862s (± 0.88%)	~	0.845s	0.882s	p=0.075 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	1.015s (± 1.02%)	1.026s (± 1.01%)	~	1.000s	1.049s	p=0.109 n=12

System info unknown

Hosts

• native

Scenarios

• Compiler-Unions - native
• angular-1 - native
• mui-docs - native
• strada-build-src - native
• strada-compiler - native
• ts-pre-modules - native
• vscode - native
• webpack - native
• xstate-main - native

Benchmark	Name	Iterations
Current	pr	12
Baseline	baseline	12

lsp

Comparison Report - baseline..pr

Metric	baseline	pr	Delta	Best	Worst	p-value
Compiler-UnionsLSP - native
Req 1 - updateOpen	15ms (± 3.34%)	15ms (± 2.92%)	~	14ms	16ms	p=0.744 n=12
Req 2 - geterr	682ms (± 0.36%)	690ms (± 0.49%)	+7ms (+ 1.09%)	679ms	698ms	p=0.001 n=12
Req 3 - references	58ms (± 4.72%)	58ms (± 6.84%)	~	47ms	63ms	p=0.965 n=12
Req 4 - navto	20ms (± 4.17%)	19ms (± 1.60%)	~	19ms	20ms	p=0.052 n=12
Req 5 - completionInfo count	1,363	1,363	~	~	~	p=1.000 n=12
Req 5 - completionInfo	19ms (±10.74%)	18ms (± 6.66%)	~	16ms	21ms	p=0.371 n=12
CompilerLSP - native
Req 1 - updateOpen	13ms (± 6.39%)	13ms (± 3.72%)	~	12ms	14ms	p=0.863 n=12
Req 2 - geterr	295ms (± 0.73%)	301ms (± 0.58%)	+6ms (+ 2.09%)	298ms	305ms	p=0.000 n=12
Req 3 - references	51ms (± 3.62%)	51ms (± 4.89%)	~	46ms	56ms	p=0.501 n=12
Req 4 - navto	18ms (± 4.47%)	17ms (± 2.95%)	~	16ms	18ms	p=0.309 n=12
Req 5 - completionInfo count	1,525	1,525	~	~	~	p=1.000 n=12
Req 5 - completionInfo	17ms (± 8.93%)	18ms (± 6.14%)	~	15ms	20ms	p=0.512 n=12

System info unknown

Hosts

• native

Scenarios

• CompilerLSP - native
• Compiler-UnionsLSP - native
• xstate-main-1-LSP - native

Benchmark	Name	Iterations
Current	pr	12
Baseline	baseline	12

startup

Comparison Report - baseline..pr

Metric	baseline	pr	Delta	Best	Worst	p-value
lsp-startup - native
Execution time	4.90ms (±365.09%)	4.72ms (±365.09%)	🟩-0.18ms (- 3.72%)	0.00ms	473.73ms	p=0.000 n=1200
tsgo-startup - native
Execution time	4.90ms (±365.10%)	4.72ms (±365.10%)	🟩-0.18ms (- 3.67%)	0.00ms	473.43ms	p=0.000 n=1200

System info unknown

Hosts

• native

Scenarios

• lsp-startup - native
• tsgo-startup - native

Benchmark	Name	Iterations
Current	pr	12
Baseline	baseline	12

Developer Information:

Download Benchmarks

[Copilot]

Pull request overview

Copilot reviewed 23 out of 26 changed files in this pull request and generated no new comments.

Files not reviewed (2)

• tsc/internal/api/encoder/encoder_generated.go: Generated file
• tsc/internal/ast/kind_stringer_generated.go: Generated file

[Copilot]

Pull request overview

Copilot reviewed 3 out of 5 changed files in this pull request and generated 2 comments.

Files not reviewed (1)

• tsc/internal/ast/kind_stringer_generated.go: Generated file

[Copilot]

Pull request overview

Copilot reviewed 3 out of 5 changed files in this pull request and generated no new comments.

Files not reviewed (1)

• tsc/internal/ast/kind_stringer_generated.go: Generated file

[Jake Bailey (jakebailey)]

TypeScript Bot (@typescript-bot) perf test this faster

[typescript-automation]

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
perf test this faster	✅ Started	👀 Results

[typescript-automation]

Jake Bailey (@jakebailey)
The results of the perf run you requested are in!

Here they are:

tsc

Comparison Report - baseline..pr

Metric	baseline	pr	Delta	Best	Worst	p-value
Compiler-Unions - native
Errors	41	41	~	~	~	p=1.000 n=12
Symbols	115,480	115,480	~	~	~	p=1.000 n=12
Types	96,945	96,945	~	~	~	p=1.000 n=12
Memory Used	148,801k (± 0.59%)	148,573k (± 0.27%)	~	147,180k	149,422k	p=0.671 n=12
Memory Allocs	2,271,201 (± 0.00%)	2,271,221 (± 0.00%)	~	2,271,070	2,271,526	p=0.712 n=12
Config Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Parse Time	0.042s (± 4.22%)	0.041s (± 3.79%)	~	0.038s	0.044s	p=0.447 n=12
Bind Time	0.012s (±12.82%)	0.014s (±12.87%)	~	0.011s	0.019s	p=0.133 n=12
Check Time	0.490s (± 0.59%)	0.495s (± 0.54%)	+0.006s (+ 1.12%)	0.489s	0.502s	p=0.015 n=12
Emit Time	0.275s (± 1.88%)	0.276s (± 2.08%)	~	0.267s	0.299s	p=0.788 n=12
Total Time	0.825s (± 0.87%)	0.832s (± 0.57%)	~	0.821s	0.848s	p=0.070 n=12
angular-1 - native
Errors	3	3	~	~	~	p=1.000 n=12
Symbols	847,129 (± 0.09%)	847,066 (± 0.03%)	~	846,619	847,610	p=0.755 n=12
Types	249,851 (± 0.00%)	249,852 (± 0.00%)	~	249,849	249,862	p=0.532 n=12
Memory Used	793,675k (± 0.07%)	793,710k (± 0.07%)	~	792,077k	795,418k	p=0.899 n=12
Memory Allocs	12,960,998 (± 0.08%)	12,954,499 (± 0.03%)	~	12,948,811	12,970,489	p=0.443 n=12
Config Time	0.016s	0.016s	~	~	~	p=1.000 n=12
Parse Time	0.274s (± 2.34%)	0.274s (± 2.61%)	~	0.258s	0.290s	p=0.809 n=12
Bind Time	0.064s (±11.03%)	0.061s (± 0.86%)	🟩-0.003s (- 4.43%)	0.060s	0.063s	p=0.035 n=12
Check Time	0s	0s	~	~	~	p=1.000 n=12
Emit Time	1.632s (± 1.26%)	1.665s (± 0.42%)	+0.033s (+ 2.03%)	1.647s	1.684s	p=0.001 n=12
Total Time	2.004s (± 1.36%)	2.034s (± 0.42%)	+0.030s (+ 1.48%)	2.017s	2.057s	p=0.004 n=12
mui-docs - native
Errors	11,275 (± 0.02%)	11,277 (± 0.03%)	~	11,261	11,281	p=0.128 n=12
Symbols	4,268,528	4,268,528	~	~	~	p=1.000 n=12
Types	1,593,260	1,593,260	~	~	~	p=1.000 n=12
Memory Used	4,729,019k (± 0.03%)	4,727,598k (± 0.03%)	~	4,724,789k	4,731,504k	p=0.128 n=12
Memory Allocs	47,640,618 (± 0.06%)	47,614,236 (± 0.03%)	~	47,586,332	47,646,477	p=0.068 n=12
Config Time	0.016s	0.016s (± 1.55%)	~	0.015s	0.016s	p=0.478 n=12
Parse Time	0.545s (± 2.60%)	0.542s (± 3.21%)	~	0.484s	0.575s	p=0.832 n=12
Bind Time	0.002s	0.002s	~	~	~	p=1.000 n=12
Check Time	16.530s (± 0.35%)	16.442s (± 0.33%)	-0.088s (- 0.53%)	16.355s	16.612s	p=0.014 n=12
Emit Time	0.432s (± 0.32%)	0.432s (± 0.39%)	~	0.429s	0.437s	p=0.944 n=12
Total Time	18.291s (± 0.39%)	18.159s (± 0.40%)	-0.133s (- 0.72%)	18.033s	18.359s	p=0.014 n=12
strada-build-src - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	1,394,252	1,394,252	~	~	~	p=1.000 n=12
Types	443,418	443,418	~	~	~	p=1.000 n=12
Memory Used	1,647,039k (± 0.13%)	1,648,683k (± 0.27%)	~	1,635,913k	1,660,011k	p=0.478 n=12
Memory Allocs	97,040,533 (± 0.02%)	97,070,577 (± 0.03%)	~	96,996,582	97,132,508	p=0.078 n=12
Config Time	0.004s (±11.61%)	0.004s (± 7.59%)	~	0.003s	0.004s	p=0.508 n=12
Parse Time	0.193s (± 2.45%)	0.195s (± 2.64%)	~	0.180s	0.213s	p=0.311 n=12
Bind Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Check Time	1.798s (± 0.34%)	1.833s (± 0.41%)	+0.035s (+ 1.96%)	1.815s	1.855s	p=0.000 n=12
Emit Time	0.291s (± 3.66%)	0.276s (± 6.19%)	~	0.244s	0.319s	p=0.174 n=12
Total Time	24.678s (± 0.71%)	25.069s (± 0.70%)	+0.390s (+ 1.58%)	24.635s	25.582s	p=0.003 n=12
strada-compiler - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	337,531	337,531	~	~	~	p=1.000 n=12
Types	198,830	198,830	~	~	~	p=1.000 n=12
Memory Used	319,495k (± 0.03%)	319,537k (± 0.02%)	~	319,342k	319,747k	p=0.713 n=12
Memory Allocs	4,673,004 (± 0.01%)	4,672,826 (± 0.01%)	~	4,671,211	4,673,631	p=0.767 n=12
Config Time	0.001s	0.001s	~	~	~	p=1.000 n=12
Parse Time	0.114s (± 4.25%)	0.118s (± 3.82%)	~	0.102s	0.127s	p=0.283 n=12
Bind Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Check Time	1.044s (± 0.38%)	1.067s (± 0.52%)	+0.023s (+ 2.19%)	1.057s	1.084s	p=0.000 n=12
Emit Time	0.146s (± 8.69%)	0.133s (±12.22%)	~	0.103s	0.169s	p=0.247 n=12
Total Time	1.355s (± 0.95%)	1.372s (± 1.03%)	~	1.348s	1.414s	p=0.080 n=12
ts-pre-modules - native
Errors	87	87	~	~	~	p=1.000 n=12
Symbols	305,179	305,179	~	~	~	p=1.000 n=12
Types	181,876	181,876	~	~	~	p=1.000 n=12
Memory Used	277,161k (± 0.03%)	277,189k (± 0.02%)	~	277,068k	277,328k	p=0.443 n=12
Memory Allocs	1,641,803 (± 0.01%)	1,642,066 (± 0.01%)	~	1,641,673	1,643,018	p=0.101 n=12
Config Time	0.000s	0.000s (±77.74%)	🔻+0.000s (+ ∞%)	0.000s	0.001s	p=0.037 n=12
Parse Time	0.098s (± 4.10%)	0.100s (± 3.56%)	~	0.093s	0.113s	p=0.450 n=12
Bind Time	0.040s (± 8.83%)	0.039s (± 7.63%)	~	0.033s	0.046s	p=0.661 n=12
Check Time	0.825s (± 0.78%)	0.848s (± 0.59%)	+0.023s (+ 2.75%)	0.837s	0.859s	p=0.000 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	0.977s (± 0.84%)	1.000s (± 0.89%)	+0.023s (+ 2.40%)	0.981s	1.025s	p=0.000 n=12
vscode - native
Errors	347	347	~	~	~	p=1.000 n=12
Symbols	8,077,966	8,077,966	~	~	~	p=1.000 n=12
Types	2,777,715	2,777,715	~	~	~	p=1.000 n=12
Memory Used	5,456,865k (± 0.01%)	5,456,728k (± 0.01%)	~	5,455,211k	5,458,619k	p=0.932 n=12
Memory Allocs	42,186,068 (± 0.03%)	42,183,294 (± 0.02%)	~	42,173,211	42,208,325	p=0.932 n=12
Config Time	0.064s (± 0.28%)	0.063s (± 0.43%)	-0.001s (- 1.69%)	0.062s	0.064s	p=0.000 n=12
Parse Time	1.633s (± 3.24%)	1.653s (± 2.41%)	~	1.512s	1.731s	p=0.681 n=12
Bind Time	0.406s (±16.32%)	0.375s (±10.52%)	~	0.350s	0.574s	p=0.123 n=12
Check Time	10.139s (± 1.47%)	10.459s (± 0.87%)	+0.319s (+ 3.15%)	10.021s	10.526s	p=0.000 n=12
Emit Time	3.585s (±11.50%)	3.347s (± 8.11%)	~	3.113s	4.709s	p=0.443 n=12
Total Time	15.923s (± 1.82%)	15.985s (± 1.30%)	~	15.698s	16.992s	p=0.143 n=12
webpack - native
Errors	540	540	~	~	~	p=1.000 n=12
Symbols	854,568	854,568	~	~	~	p=1.000 n=12
Types	392,241	392,241	~	~	~	p=1.000 n=12
Memory Used	653,940k (± 0.02%)	653,954k (± 0.02%)	~	653,520k	654,285k	p=0.932 n=12
Memory Allocs	4,372,616 (± 0.04%)	4,371,810 (± 0.03%)	~	4,369,781	4,375,834	p=0.514 n=12
Config Time	0.008s	0.008s	~	~	~	p=1.000 n=12
Parse Time	0.213s (± 2.69%)	0.216s (± 2.89%)	~	0.202s	0.236s	p=0.618 n=12
Bind Time	0.044s (±15.00%)	0.044s (± 7.80%)	+0.001s (+ 1.33%)	0.041s	0.057s	p=0.042 n=12
Check Time	1.375s (± 0.75%)	1.394s (± 0.66%)	+0.020s (+ 1.45%)	1.369s	1.415s	p=0.005 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	1.662s (± 0.52%)	1.687s (± 0.48%)	+0.025s (+ 1.50%)	1.667s	1.707s	p=0.000 n=12
xstate-main - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	1,022,487	1,022,487	~	~	~	p=1.000 n=12
Types	376,962	376,962	~	~	~	p=1.000 n=12
Memory Used	603,518k (± 0.01%)	603,559k (± 0.01%)	~	603,410k	603,712k	p=0.266 n=12
Memory Allocs	4,754,306 (± 0.04%)	4,757,092 (± 0.10%)	~	4,750,768	4,776,446	p=0.514 n=12
Config Time	0.003s	0.003s (± 8.64%)	~	0.002s	0.003s	p=0.478 n=12
Parse Time	0.145s (± 3.25%)	0.145s (± 3.14%)	~	0.133s	0.158s	p=0.660 n=12
Bind Time	0.045s (±18.87%)	0.047s (±20.52%)	~	0.034s	0.074s	p=0.637 n=12
Check Time	1.035s (± 0.81%)	1.043s (± 0.84%)	~	1.022s	1.075s	p=0.235 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	1.238s (± 0.91%)	1.249s (± 1.08%)	~	1.220s	1.278s	p=0.116 n=12

System info unknown

Hosts

• native

Scenarios

• Compiler-Unions - native
• angular-1 - native
• mui-docs - native
• strada-build-src - native
• strada-compiler - native
• ts-pre-modules - native
• vscode - native
• webpack - native
• xstate-main - native

Benchmark	Name	Iterations
Current	pr	12
Baseline	baseline	12

Developer Information:

Download Benchmarks

[Gabriela Araujo Britto (gabritto)]

This looks good to me, and like I said, better for the upcoming extra type checking, but not sure other people have opinions.

[Jake Bailey (jakebailey)]

This should be perf neutral but trying one more time

TypeScript Bot (@typescript-bot) perf test this faster

[typescript-automation]

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
perf test this faster	✅ Started	👀 Results

[typescript-automation]

Jake Bailey (@jakebailey)
The results of the perf run you requested are in!

Here they are:

tsc

Comparison Report - baseline..pr

Metric	baseline	pr	Delta	Best	Worst	p-value
Compiler-Unions - native
Errors	41	41	~	~	~	p=1.000 n=12
Symbols	115,480	115,480	~	~	~	p=1.000 n=12
Types	96,945	96,945	~	~	~	p=1.000 n=12
Memory Used	148,452k (± 0.42%)	149,150k (± 0.48%)	~	147,423k	150,802k	p=0.198 n=12
Memory Allocs	2,271,193 (± 0.00%)	2,271,186 (± 0.00%)	~	2,271,037	2,271,333	p=0.876 n=12
Config Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Parse Time	0.041s (± 3.96%)	0.040s (± 2.44%)	~	0.038s	0.042s	p=0.121 n=12
Bind Time	0.012s (±10.28%)	0.012s (±10.28%)	~	0.010s	0.018s	p=0.503 n=12
Check Time	0.496s (± 0.90%)	0.497s (± 1.00%)	~	0.488s	0.512s	p=0.944 n=12
Emit Time	0.271s (± 1.98%)	0.270s (± 2.01%)	~	0.261s	0.291s	p=0.385 n=12
Total Time	0.827s (± 0.96%)	0.824s (± 1.08%)	~	0.810s	0.853s	p=0.369 n=12
angular-1 - native
Errors	3	3	~	~	~	p=1.000 n=12
Symbols	847,908 (± 0.04%)	847,103 (± 0.10%)	~	843,970	848,488	p=0.178 n=12
Types	249,852 (± 0.00%)	249,851 (± 0.00%)	~	249,849	249,853	p=0.795 n=12
Memory Used	793,391k (± 0.08%)	793,616k (± 0.06%)	~	792,464k	794,710k	p=0.410 n=12
Memory Allocs	12,952,519 (± 0.04%)	12,953,518 (± 0.04%)	~	12,949,220	12,979,915	p=0.178 n=12
Config Time	0.016s	0.016s	~	~	~	p=1.000 n=12
Parse Time	0.274s (± 1.58%)	0.269s (± 3.17%)	~	0.242s	0.285s	p=0.417 n=12
Bind Time	0.063s (± 7.27%)	0.068s (±13.67%)	🔻+0.005s (+ 8.79%)	0.060s	0.106s	p=0.013 n=12
Check Time	0s	0s	~	~	~	p=1.000 n=12
Emit Time	1.640s (± 0.97%)	1.678s (± 1.27%)	+0.038s (+ 2.33%)	1.640s	1.744s	p=0.001 n=12
Total Time	2.010s (± 1.13%)	2.049s (± 1.40%)	+0.039s (+ 1.94%)	2.000s	2.135s	p=0.014 n=12
mui-docs - native
Errors	11,276 (± 0.03%)	11,279 (± 0.01%)	~	11,276	11,281	p=0.195 n=12
Symbols	4,169,590	4,169,590	~	~	~	p=1.000 n=12
Types	1,577,454	1,577,454	~	~	~	p=1.000 n=12
Memory Used	4,678,165k (± 0.04%)	4,678,893k (± 0.03%)	~	4,676,569k	4,682,543k	p=0.478 n=12
Memory Allocs	47,014,381 (± 0.04%)	47,014,840 (± 0.03%)	~	46,966,711	47,061,525	p=0.843 n=12
Config Time	0.016s (± 1.14%)	0.016s (± 1.14%)	~	0.015s	0.016s	p=1.000 n=12
Parse Time	0.553s (± 2.05%)	0.547s (± 2.52%)	~	0.492s	0.565s	p=0.788 n=12
Bind Time	0.002s	0.002s (±24.21%)	~	0.002s	0.005s	p=1.000 n=12
Check Time	17.292s (± 0.43%)	17.408s (± 0.58%)	~	17.219s	17.616s	p=0.060 n=12
Emit Time	0.434s (± 0.30%)	0.440s (± 2.92%)	~	0.431s	0.504s	p=0.969 n=12
Total Time	19.031s (± 0.48%)	19.171s (± 0.58%)	+0.140s (+ 0.74%)	18.959s	19.393s	p=0.033 n=12
strada-build-src - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	1,394,252	1,394,252	~	~	~	p=1.000 n=12
Types	443,418	443,418	~	~	~	p=1.000 n=12
Memory Used	1,646,361k (± 0.20%)	1,641,215k (± 0.39%)	~	1,627,712k	1,661,573k	p=0.128 n=12
Memory Allocs	97,045,077 (± 0.02%)	97,001,871 (± 0.05%)	-43,206 (- 0.04%)	96,919,801	97,181,276	p=0.008 n=12
Config Time	0.004s (±12.60%)	0.004s (±17.94%)	~	0.002s	0.007s	p=0.619 n=12
Parse Time	0.194s (± 3.48%)	0.188s (± 1.73%)	~	0.181s	0.198s	p=0.247 n=12
Bind Time	0.000s	0.000s (±217.90%)	~	0.000s	0.002s	p=1.000 n=12
Check Time	1.809s (± 0.44%)	1.833s (± 0.41%)	+0.024s (+ 1.34%)	1.810s	1.851s	p=0.000 n=12
Emit Time	0.282s (± 5.32%)	0.293s (± 4.70%)	~	0.251s	0.327s	p=0.219 n=12
Total Time	24.799s (± 0.48%)	25.028s (± 0.50%)	+0.229s (+ 0.92%)	24.728s	25.360s	p=0.020 n=12
strada-compiler - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	337,531	337,531	~	~	~	p=1.000 n=12
Types	198,830	198,830	~	~	~	p=1.000 n=12
Memory Used	319,536k (± 0.05%)	319,643k (± 0.08%)	~	319,177k	320,842k	p=0.410 n=12
Memory Allocs	4,673,076 (± 0.01%)	4,672,950 (± 0.01%)	~	4,671,172	4,673,778	p=0.977 n=12
Config Time	0.001s	0.001s	~	~	~	p=1.000 n=12
Parse Time	0.117s (± 4.12%)	0.114s (± 4.55%)	~	0.100s	0.126s	p=0.384 n=12
Bind Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Check Time	1.053s (± 0.54%)	1.067s (± 0.64%)	+0.014s (+ 1.34%)	1.053s	1.091s	p=0.002 n=12
Emit Time	0.140s (±13.52%)	0.143s (±10.65%)	~	0.110s	0.174s	p=0.744 n=12
Total Time	1.364s (± 1.35%)	1.379s (± 0.77%)	~	1.353s	1.410s	p=0.235 n=12
ts-pre-modules - native
Errors	87	87	~	~	~	p=1.000 n=12
Symbols	305,179	305,179	~	~	~	p=1.000 n=12
Types	181,876	181,876	~	~	~	p=1.000 n=12
Memory Used	277,193k (± 0.02%)	277,184k (± 0.02%)	~	276,987k	277,320k	p=0.724 n=12
Memory Allocs	1,641,869 (± 0.01%)	1,641,799 (± 0.01%)	~	1,641,349	1,642,325	p=0.590 n=12
Config Time	0.000s (±217.90%)	0.000s (±217.90%)	~	0.000s	0.001s	p=1.000 n=12
Parse Time	0.103s (± 3.04%)	0.100s (± 4.44%)	~	0.088s	0.110s	p=0.369 n=12
Bind Time	0.035s (±12.75%)	0.036s (± 9.55%)	~	0.029s	0.047s	p=0.559 n=12
Check Time	0.833s (± 0.69%)	0.850s (± 0.51%)	+0.018s (+ 2.13%)	0.842s	0.861s	p=0.000 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	0.984s (± 0.96%)	0.999s (± 0.80%)	+0.015s (+ 1.53%)	0.982s	1.019s	p=0.015 n=12
vscode - native
Errors	347	347	~	~	~	p=1.000 n=12
Symbols	8,236,705	8,236,705	~	~	~	p=1.000 n=12
Types	2,824,778	2,824,778	~	~	~	p=1.000 n=12
Memory Used	5,548,891k (± 0.02%)	5,549,162k (± 0.01%)	~	5,547,084k	5,550,587k	p=0.561 n=12
Memory Allocs	42,694,842 (± 0.01%)	42,698,786 (± 0.02%)	~	42,688,501	42,747,165	p=0.319 n=12
Config Time	0.064s (± 0.52%)	0.063s (± 0.29%)	~	0.063s	0.064s	p=0.069 n=12
Parse Time	1.644s (± 2.78%)	1.639s (± 2.40%)	~	1.523s	1.708s	p=0.766 n=12
Bind Time	0.394s (±13.56%)	0.388s (±10.23%)	~	0.359s	0.558s	p=0.084 n=12
Check Time	10.363s (± 1.57%)	10.638s (± 1.29%)	+0.275s (+ 2.66%)	10.166s	10.792s	p=0.003 n=12
Emit Time	3.740s (±11.47%)	3.508s (±10.64%)	~	3.149s	4.998s	p=0.767 n=12
Total Time	16.302s (± 1.77%)	16.330s (± 1.63%)	~	15.986s	17.418s	p=0.551 n=12
webpack - native
Errors	544	544	~	~	~	p=1.000 n=12
Symbols	858,575	858,575	~	~	~	p=1.000 n=12
Types	396,099	396,099	~	~	~	p=1.000 n=12
Memory Used	658,559k (± 0.02%)	658,512k (± 0.03%)	~	657,858k	659,304k	p=0.410 n=12
Memory Allocs	4,388,526 (± 0.02%)	4,388,378 (± 0.02%)	~	4,386,510	4,392,543	p=0.755 n=12
Config Time	0.008s	0.008s (± 5.88%)	~	0.008s	0.010s	p=0.478 n=12
Parse Time	0.214s (± 2.09%)	0.218s (± 2.78%)	~	0.199s	0.231s	p=0.234 n=12
Bind Time	0.043s (± 6.95%)	0.052s (±17.77%)	🔻+0.009s (+22.07%)	0.042s	0.079s	p=0.001 n=12
Check Time	1.295s (± 0.87%)	1.333s (± 0.88%)	+0.038s (+ 2.90%)	1.297s	1.369s	p=0.000 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	1.584s (± 0.68%)	1.636s (± 0.65%)	+0.053s (+ 3.34%)	1.612s	1.668s	p=0.000 n=12
xstate-main - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	1,022,532	1,022,532	~	~	~	p=1.000 n=12
Types	376,962	376,962	~	~	~	p=1.000 n=12
Memory Used	603,547k (± 0.01%)	603,489k (± 0.01%)	~	603,152k	603,670k	p=0.291 n=12
Memory Allocs	4,753,967 (± 0.04%)	4,753,718 (± 0.03%)	~	4,749,569	4,757,679	p=0.843 n=12
Config Time	0.003s (±11.61%)	0.003s (± 8.64%)	~	0.002s	0.003s	p=0.640 n=12
Parse Time	0.147s (± 3.12%)	0.150s (± 4.15%)	~	0.136s	0.162s	p=0.468 n=12
Bind Time	0.045s (±21.77%)	0.046s (±14.68%)	~	0.034s	0.068s	p=0.352 n=12
Check Time	1.034s (± 1.06%)	1.055s (± 1.99%)	+0.020s (+ 1.95%)	1.030s	1.151s	p=0.012 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	1.239s (± 1.06%)	1.264s (± 2.28%)	~	1.223s	1.388s	p=0.110 n=12

System info unknown

Hosts

• native

Scenarios

• Compiler-Unions - native
• angular-1 - native
• mui-docs - native
• strada-build-src - native
• strada-compiler - native
• ts-pre-modules - native
• vscode - native
• webpack - native
• xstate-main - native

Benchmark	Name	Iterations
Current	pr	12
Baseline	baseline	12

Developer Information:

Download Benchmarks

[Jake Bailey (jakebailey)]

Hm, there's something to this, I think, I need to investigate.