Switch to using yarn v4

[acoates-ms]

Description

Currently we are using midgard-yarn which is a custom fork of yarnv1 to improve perfomance. Most of the performance improvements in this fork were adopted by yarn 4. So we can move of the more custom midgard-yarn, on to a more broadly supported version of yarn.

[iamAbhi-916]

LGTM

[github-actions]

Performance Test Results

Branch: yarn4
Commit: 2dda3ae0
Time: 2026-04-06T17:43:13.200Z
Tests: 161/161 passed

✅ Passed

161 scenario(s) across 28 suite(s) — no regressions

SectionList

Scenario	Mean	Median	StdDev	Renders	vs Baseline
SectionList mount	5.50ms	5.00ms	±1.78ms	1	+0.0%
SectionList unmount	0.20ms	0.00ms	±0.42ms	0	+0.0%
SectionList rerender	13.50ms	13.50ms	±2.72ms	2	+28.6%
SectionList with-3-sections-15-items	6.40ms	6.50ms	±1.65ms	1	+18.2%
SectionList with-5-sections-50-items	6.50ms	5.50ms	±2.68ms	1	-8.3%
SectionList with-10-sections-200-items	5.70ms	5.00ms	±1.77ms	1	-9.1%
SectionList with-20-sections-200-items	5.90ms	6.00ms	±1.91ms	1	+20.0%
SectionList with-section-separator	1.90ms	2.00ms	±0.74ms	1	+0.0%
SectionList with-item-separator	4.60ms	3.50ms	±4.43ms	1	+75.0%
SectionList with-header-footer	3.10ms	3.00ms	±0.57ms	1	+50.0%
SectionList with-section-footer	2.20ms	2.00ms	±0.42ms	1	+0.0%
SectionList with-sticky-section-headers	1.90ms	1.50ms	±1.29ms	1	-25.0%
SectionList with-empty-list	1.00ms	1.00ms	±1.49ms	1	+0.0%
SectionList with-50-sections-1000-items	1.40ms	1.00ms	±0.52ms	1	-50.0%

FlatList

Scenario	Mean	Median	StdDev	Renders	vs Baseline
FlatList mount	4.90ms	4.50ms	±1.29ms	1	+12.5%
FlatList unmount	0.20ms	0.00ms	±0.42ms	0	+0.0%
FlatList rerender	10.90ms	11.00ms	±0.99ms	2	+22.2%
FlatList with-10-items	5.30ms	5.00ms	±0.67ms	1	+25.0%
FlatList with-100-items	6.40ms	7.00ms	±1.26ms	1	+40.0%
FlatList with-500-items	6.50ms	5.00ms	±3.47ms	1	+25.0%
FlatList with-1000-items	5.50ms	5.00ms	±0.71ms	1	+25.0%
FlatList horizontal	5.00ms	5.00ms	±1.15ms	1	+0.0%
FlatList with-separator	2.00ms	2.00ms	±0.47ms	1	+0.0%
FlatList with-header-footer	1.60ms	2.00ms	±0.52ms	1	+0.0%
FlatList with-empty-list	0.50ms	0.50ms	±0.53ms	1	+0.0%
FlatList with-get-item-layout	1.50ms	1.50ms	±0.53ms	1	+50.0%
FlatList inverted	1.70ms	2.00ms	±0.67ms	1	+33.3%
FlatList with-num-columns	2.80ms	3.00ms	±0.63ms	1	+0.0%

TouchableOpacity

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TouchableOpacity mount	1.00ms	1.00ms	±0.00ms	1	+0.0%
TouchableOpacity unmount	0.10ms	0.00ms	±0.32ms	0	+0.0%
TouchableOpacity rerender	1.00ms	1.00ms	±0.82ms	2	+0.0%
TouchableOpacity custom-active-opacity	0.50ms	0.50ms	±0.53ms	1	-50.0%
TouchableOpacity disabled	0.80ms	1.00ms	±0.42ms	1	+0.0%
TouchableOpacity with-all-handlers	0.70ms	1.00ms	±0.48ms	1	+0.0%
TouchableOpacity with-hit-slop	1.00ms	1.00ms	±0.47ms	1	+0.0%
TouchableOpacity with-delay	0.80ms	1.00ms	±0.42ms	1	+0.0%
TouchableOpacity nested	1.40ms	1.00ms	±0.52ms	1	+0.0%
TouchableOpacity multiple-10	7.00ms	6.00ms	±2.10ms	1	+0.0%
TouchableOpacity multiple-50	34.27ms	33.00ms	±7.75ms	1	+13.8%
TouchableOpacity multiple-100	48.53ms	51.00ms	±14.18ms	1	+2.0%

ScrollView

Scenario	Mean	Median	StdDev	Renders	vs Baseline
ScrollView mount	0.40ms	0.00ms	±0.52ms	1	+0.0%
ScrollView unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
ScrollView rerender	0.70ms	1.00ms	±0.48ms	2	+0.0%
ScrollView children-20	4.40ms	4.00ms	±2.38ms	1	+0.0%
ScrollView children-100	19.20ms	19.00ms	±4.51ms	1	+18.8%
ScrollView horizontal	5.20ms	5.00ms	±1.55ms	1	+25.0%
ScrollView sticky-headers	3.00ms	3.00ms	±0.94ms	1	+0.0%
ScrollView scroll-indicators	0.70ms	1.00ms	±0.48ms	1	+0.0%
ScrollView nested	1.90ms	1.50ms	±1.29ms	1	+50.0%
ScrollView content-container-style	1.30ms	1.00ms	±2.06ms	1	+0.0%
ScrollView children-500	21.60ms	21.00ms	±3.25ms	1	+10.5%

TouchableHighlight

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TouchableHighlight mount	0.50ms	0.50ms	±0.53ms	1	+0.0%
TouchableHighlight unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
TouchableHighlight rerender	0.70ms	1.00ms	±0.48ms	2	+0.0%
TouchableHighlight custom-underlay-color	0.40ms	0.00ms	±0.52ms	1	+0.0%
TouchableHighlight custom-active-opacity	0.50ms	0.50ms	±0.53ms	1	+Infinity%
TouchableHighlight disabled	0.30ms	0.00ms	±0.48ms	1	+0.0%
TouchableHighlight with-all-handlers	0.30ms	0.00ms	±0.48ms	1	+0.0%
TouchableHighlight with-hit-slop	0.30ms	0.00ms	±0.48ms	1	+0.0%
TouchableHighlight nested-touchables	0.70ms	1.00ms	±0.48ms	1	+0.0%
TouchableHighlight multiple-touchables-10	2.80ms	2.50ms	±1.62ms	1	-16.7%
TouchableHighlight multiple-touchables-50	16.70ms	15.50ms	±3.71ms	1	+24.0%
TouchableHighlight multiple-touchables-100	26.10ms	25.00ms	±4.89ms	1	+11.1%

Pressable

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Pressable mount	0.50ms	0.50ms	±0.53ms	1	+Infinity%
Pressable unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
Pressable rerender	0.70ms	1.00ms	±0.48ms	2	+100.0%
Pressable with-all-handlers	0.40ms	0.00ms	±0.52ms	1	+0.0%
Pressable with-style-function	0.40ms	0.00ms	±0.52ms	1	+0.0%
Pressable disabled	0.40ms	0.00ms	±0.52ms	1	+0.0%
Pressable with-hit-slop	0.30ms	0.00ms	±0.48ms	1	+0.0%
Pressable nested	0.80ms	1.00ms	±0.42ms	1	+0.0%
Pressable multiple-10	3.20ms	3.00ms	±0.68ms	1	+0.0%
Pressable multiple-50	17.73ms	18.00ms	±3.13ms	1	+28.6%
Pressable multiple-100	19.93ms	13.00ms	±12.65ms	1	+8.3%

Modal

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Modal mount	0.40ms	0.00ms	±0.52ms	1	+0.0%
Modal unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
Modal rerender	0.50ms	0.50ms	±0.53ms	2	+Infinity%
Modal slide-animation	0.40ms	0.00ms	±0.52ms	1	+0.0%
Modal fade-animation	0.30ms	0.00ms	±0.48ms	1	+0.0%
Modal transparent	0.40ms	0.00ms	±0.52ms	1	+0.0%
Modal with-callbacks	0.30ms	0.00ms	±0.48ms	1	+0.0%
Modal rich-content	1.70ms	2.00ms	±0.67ms	1	+0.0%
Modal with-accessibility	0.20ms	0.00ms	±0.42ms	1	+0.0%

Image

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Image mount	0.10ms	0.00ms	±0.32ms	1	+0.0%
Image unmount	0.10ms	0.00ms	±0.32ms	0	+0.0%
Image rerender	0.20ms	0.00ms	±0.42ms	2	+0.0%
Image with-resize-mode	0.20ms	0.00ms	±0.42ms	1	+0.0%
Image with-border-radius	0.20ms	0.00ms	±0.42ms	1	+0.0%
Image with-tint-color	0.20ms	0.00ms	±0.42ms	1	+0.0%
Image with-blur-radius	0.10ms	0.00ms	±0.32ms	1	+0.0%
Image with-accessibility	0.10ms	0.00ms	±0.32ms	1	+0.0%
Image multiple-10	1.00ms	1.00ms	±0.00ms	1	+0.0%
Image multiple-50	4.13ms	4.00ms	±1.51ms	1	+33.3%
Image multiple-100	9.20ms	8.00ms	±2.01ms	1	+0.0%

ActivityIndicator

Scenario	Mean	Median	StdDev	Renders	vs Baseline
ActivityIndicator mount	0.20ms	0.00ms	±0.42ms	1	+0.0%
ActivityIndicator unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
ActivityIndicator rerender	0.20ms	0.00ms	±0.42ms	2	+0.0%
ActivityIndicator size-large	0.20ms	0.00ms	±0.42ms	1	+0.0%
ActivityIndicator size-small	0.10ms	0.00ms	±0.32ms	1	+0.0%
ActivityIndicator with-color	0.20ms	0.00ms	±0.42ms	1	+0.0%
ActivityIndicator not-animating	0.20ms	0.00ms	±0.42ms	1	+0.0%
ActivityIndicator with-accessibility	0.20ms	0.00ms	±0.42ms	1	+0.0%
ActivityIndicator multiple-10	0.87ms	1.00ms	±0.35ms	1	+0.0%
ActivityIndicator multiple-50	5.00ms	5.00ms	±1.81ms	1	+25.0%
ActivityIndicator multiple-100	11.20ms	10.00ms	±2.93ms	1	+42.9%

Switch

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Switch mount	0.40ms	0.00ms	±0.52ms	1	+0.0%
Switch unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
Switch rerender	0.40ms	0.00ms	±0.52ms	2	-100.0%
Switch value-true	0.20ms	0.00ms	±0.42ms	1	+0.0%
Switch disabled	0.30ms	0.00ms	±0.48ms	1	+0.0%
Switch custom-colors	0.10ms	0.00ms	±0.32ms	1	+0.0%
Switch on-value-change	0.30ms	0.00ms	±0.48ms	1	+0.0%
Switch with-accessibility	0.20ms	0.00ms	±0.42ms	1	+0.0%
Switch multiple-10	1.93ms	2.00ms	±1.03ms	1	+0.0%
Switch multiple-50	11.33ms	9.00ms	±3.64ms	1	+0.0%
Switch multiple-100	21.73ms	19.00ms	±5.12ms	1	+18.8%

Button

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Button mount	1.00ms	1.00ms	±0.00ms	1	+0.0%
Button unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
Button rerender	2.20ms	2.00ms	±0.42ms	2	+100.0%
Button disabled	1.30ms	1.00ms	±0.48ms	1	+0.0%
Button with-color	1.10ms	1.00ms	±0.32ms	1	+100.0%
Button with-accessibility	1.30ms	1.00ms	±0.48ms	1	+0.0%
Button multiple-10	7.00ms	6.00ms	±2.04ms	1	+0.0%
Button multiple-50	25.20ms	26.00ms	±11.18ms	1	-3.7%
Button multiple-100	25.67ms	20.00ms	±14.83ms	1	+5.3%

TextInput

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TextInput mount	0.20ms	0.00ms	±0.42ms	1	+0.0%
TextInput unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
TextInput rerender	0.20ms	0.00ms	±0.42ms	2	+0.0%
TextInput multiline	0.30ms	0.00ms	±0.48ms	1	+0.0%
TextInput with-value	0.20ms	0.00ms	±0.42ms	1	+0.0%
TextInput styled	0.10ms	0.00ms	±0.32ms	1	+0.0%
TextInput multiple-100	9.40ms	9.00ms	±2.44ms	1	+28.6%

View

Scenario	Mean	Median	StdDev	Renders	vs Baseline
View mount	0.20ms	0.00ms	±0.42ms	1	+0.0%
View unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
View rerender	0.30ms	0.00ms	±0.48ms	2	+0.0%
View nested-50	3.87ms	4.00ms	±0.83ms	1	+33.3%
View nested-100	9.93ms	8.00ms	±2.49ms	1	+14.3%
View shadow	0.20ms	0.00ms	±0.42ms	1	+0.0%
View border-radius	0.20ms	0.00ms	±0.42ms	1	+0.0%
View nested-500	19.93ms	13.00ms	±15.59ms	1	+30.0%

Text

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Text mount	0.40ms	0.00ms	±0.52ms	1	+0.0%
Text unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
Text rerender	0.20ms	0.00ms	±0.42ms	2	+0.0%
Text long-1000	0.00ms	0.00ms	±0.00ms	1	+0.0%
Text nested	0.20ms	0.00ms	±0.42ms	1	+0.0%
Text styled	0.30ms	0.00ms	±0.48ms	1	+0.0%
Text multiple-100	9.73ms	9.00ms	±1.91ms	1	+28.6%

SectionList.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
SectionList native mount	7.52ms	6.74ms	±1.59ms	1	+3.6%

FlatList.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
FlatList native mount	7.41ms	6.86ms	±1.47ms	1	-25.7%

TouchableHighlight.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TouchableHighlight native mount	1.91ms	1.81ms	±0.20ms	1	-13.3%

TouchableOpacity.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TouchableOpacity native mount	2.52ms	2.14ms	±1.05ms	1	-31.9%

Pressable.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Pressable native mount	1.93ms	1.85ms	±0.29ms	1	-26.4%

ScrollView.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
ScrollView native mount	4.30ms	4.28ms	±0.60ms	1	+5.8%

ActivityIndicator.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
ActivityIndicator native mount	1.60ms	1.56ms	±0.17ms	1	-37.4%

TextInput.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TextInput native mount	2.86ms	2.84ms	±0.50ms	1	-30.4%

Switch.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Switch native mount	1.66ms	1.55ms	±0.38ms	1	-10.7%

Button.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Button native mount	2.61ms	2.32ms	±0.88ms	1	-10.8%

Modal.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Modal native mount	1.40ms	1.28ms	±0.39ms	1	+5.2%

Image.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Image native mount	2.48ms	2.11ms	±1.04ms	1	-6.5%

View.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
View native mount	1.62ms	1.40ms	±0.74ms	1	-1.8%

Text.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Text native mount	1.77ms	1.72ms	±0.19ms	1	-1.0%