feat(SkeletonBox): Convert SkeletonBox to CSS modules behind the feature flag

.changeset/few-zebras-drive.md

@@ -0,0 +1,8 @@
+---
+"@primer/react": minor
+---
+
+* Convert SkeletonAvatar to CSS modules behind the feature flag
+* Convert SkeletonBox to CSS modules behind the feature flag
+* Convert SkeletonText to CSS modules behind the feature flag
+

packages/react/src/experimental/Skeleton/SkeletonAvatar.module.css

@@ -0,0 +1,34 @@
+.SkeletonAvatar {
+  &:where([data-component='SkeletonAvatar']) {
+    display: inline-block;
+    width: var(--avatarSize-regular);
+    height: var(--avatarSize-regular);
+    /* stylelint-disable-next-line primer/typography */
+    line-height: 1;
+    border-radius: 50%;
+    /* stylelint-disable-next-line primer/box-shadow */
+    box-shadow: 0 0 0 1px var(--avatar-borderColor);
+  }
+
+  &:where([data-square]) {
+    /* stylelint-disable-next-line primer/borders */
+    border-radius: clamp(4px, var(--avatarSize-regular) - 24px, var(--borderRadius-medium));
+  }
+
+  &:where([data-responsive]) {
+    @media screen and (--viewportRange-narrow) {
+      width: var(--avatarSize-narrow);
+      height: var(--avatarSize-narrow);
+    }
+
+    @media screen and (--viewportRange-regular) {
+      width: var(--avatarSize-regular);
+      height: var(--avatarSize-regular);
+    }
+
+    @media screen and (--viewportRange-wide) {
+      width: var(--avatarSize-wide);
+      height: var(--avatarSize-wide);
+    }
+  }
+}

packages/react/src/experimental/Skeleton/SkeletonAvatar.stories.tsx

@@ -28,6 +28,11 @@ Playground.args = {
 }
 
 Playground.argTypes = {
+  square: {
+    control: {
+      type: 'boolean',
+    },
+  },
   size: {
     control: {
       type: 'number',

packages/react/src/experimental/Skeleton/SkeletonAvatar.tsx

@@ -1,15 +1,19 @@
-import React from 'react'
+import React, {type CSSProperties} from 'react'
 import {getBreakpointDeclarations} from '../../utils/getBreakpointDeclarations'
 import {get} from '../../constants'
 import {isResponsiveValue} from '../../hooks/useResponsiveValue'
 import type {AvatarProps} from '../../Avatar'
 import {DEFAULT_AVATAR_SIZE} from '../../Avatar/Avatar'
 import {SkeletonBox} from './SkeletonBox'
+import classes from './SkeletonAvatar.module.css'
+import {clsx} from 'clsx'
+import {useFeatureFlag} from '../../FeatureFlags'
+import {merge} from '../../sx'
 
 export type SkeletonAvatarProps = Pick<AvatarProps, 'size' | 'square'> & {
   /** Class name for custom styling */
   className?: string
-}
+} & Omit<React.HTMLProps<HTMLDivElement>, 'size'>
 
 const avatarSkeletonStyles = {
   '&[data-component="SkeletonAvatar"]': {
@@ -21,13 +25,22 @@ const avatarSkeletonStyles = {
     width: 'var(--avatar-size)',
   },
 
-  '&[data-avatar-shape="square"]': {
+  '&[data-square]': {
     borderRadius: 'clamp(4px, var(--avatar-size) - 24px, 6px)',
   },
 }
 
-export const SkeletonAvatar: React.FC<SkeletonAvatarProps> = ({size = DEFAULT_AVATAR_SIZE, square, ...rest}) => {
-  const avatarSx = isResponsiveValue(size)
+export const SkeletonAvatar: React.FC<SkeletonAvatarProps> = ({
+  size = DEFAULT_AVATAR_SIZE,
+  square,
+  className,
+  style,
+  ...rest
+}) => {
+  const responsive = isResponsiveValue(size)
+  const cssSizeVars = {} as Record<string, string>
+  const enabled = useFeatureFlag('primer_react_css_modules_team')
+  const avatarSx = responsive
     ? {
         ...getBreakpointDeclarations(
           size,
@@ -41,12 +54,25 @@ export const SkeletonAvatar: React.FC<SkeletonAvatarProps> = ({size = DEFAULT_AV
         ...avatarSkeletonStyles,
       }
 
+  if (enabled) {
+    if (responsive) {
+      for (const [key, value] of Object.entries(size)) {
+        cssSizeVars[`--avatarSize-${key}`] = `${value}px`
+      }
+    } else {
+      cssSizeVars['--avatarSize-regular'] = `${size}px`
+    }
+  }
+
   return (
     <SkeletonBox
-      sx={avatarSx}
+      sx={enabled ? undefined : avatarSx}
+      className={clsx(className, {[classes.SkeletonAvatar]: enabled})}
       {...rest}
       data-component="SkeletonAvatar"
-      data-avatar-shape={square ? 'square' : undefined}
+      data-responsive={responsive ? '' : undefined}
+      data-square={square ? '' : undefined}
+      style={merge(style as CSSProperties, enabled ? cssSizeVars : {})}
     />
   )
 }

packages/react/src/experimental/Skeleton/SkeletonBox.module.css

@@ -0,0 +1,30 @@
+@keyframes shimmer {
+  from {
+    mask-position: 200%;
+  }
+
+  to {
+    mask-position: 0%;
+  }
+}
+
+.SkeletonBox {
+  display: block;
+  height: 1rem;
+  background-color: var(--bgColor-muted);
+  border-radius: var(--borderRadius-small);
+  animation: shimmer;
+
+  @media (prefers-reduced-motion: no-preference) {
+    mask-image: linear-gradient(75deg, #000 30%, rgba(0, 0, 0, 0.65) 80%);
+    mask-size: 200%;
+    animation: shimmer;
+    animation-duration: 1s;
+    animation-iteration-count: infinite;
+  }
+
+  @media (forced-colors: active) {
+    outline: 1px solid transparent;
+    outline-offset: -1px;
+  }
+}

packages/react/src/experimental/Skeleton/SkeletonBox.tsx

@@ -1,40 +1,80 @@
-import type React from 'react'
+import React from 'react'
 import styled, {keyframes} from 'styled-components'
-import sx, {type SxProp} from '../../sx'
+import sx, {merge, type SxProp} from '../../sx'
 import {get} from '../../constants'
+import {type CSSProperties, type HTMLProps} from 'react'
+import {toggleStyledComponent} from '../../internal/utils/toggleStyledComponent'
+import {clsx} from 'clsx'
+import classes from './SkeletonBox.module.css'
+import {useFeatureFlag} from '../../FeatureFlags'
 
 type SkeletonBoxProps = {
   /** Height of the skeleton "box". Accepts any valid CSS `height` value. */
-  height?: React.CSSProperties['height']
+  height?: CSSProperties['height']
   /** Width of the skeleton "box". Accepts any valid CSS `width` value. */
-  width?: React.CSSProperties['width']
-} & SxProp
+  width?: CSSProperties['width']
+  /** The className of the skeleton box */
+  className?: string
+} & SxProp &
+  HTMLProps<HTMLDivElement>
 
 const shimmer = keyframes`
   from { mask-position: 200%; }
   to { mask-position: 0%; }
 `
+const CSS_MODULES_FEATURE_FLAG = 'primer_react_css_modules_team'
 
-export const SkeletonBox = styled.div<SkeletonBoxProps>`
-  animation: ${shimmer};
-  display: block;
-  background-color: var(--bgColor-muted, ${get('colors.canvas.subtle')});
-  border-radius: 3px;
-  height: ${props => props.height || '1rem'};
-  width: ${props => props.width};
-
-  @media (prefers-reduced-motion: no-preference) {
-    mask-image: linear-gradient(75deg, #000 30%, rgba(0, 0, 0, 0.65) 80%);
-    mask-size: 200%;
+const StyledSkeletonBox = toggleStyledComponent(
+  CSS_MODULES_FEATURE_FLAG,
+  'div',
+  styled.div<SkeletonBoxProps>`
     animation: ${shimmer};
-    animation-duration: 1s;
-    animation-iteration-count: infinite;
-  }
+    display: block;
+    background-color: var(--bgColor-muted, ${get('colors.canvas.subtle')});
+    border-radius: 3px;
+    height: ${props => props.height || '1rem'};
+    width: ${props => props.width};
 
-  @media (forced-colors: active) {
-    outline: 1px solid transparent;
-    outline-offset: -1px;
-  }
+    @media (prefers-reduced-motion: no-preference) {
+      mask-image: linear-gradient(75deg, #000 30%, rgba(0, 0, 0, 0.65) 80%);
+      mask-size: 200%;
+      animation: ${shimmer};
+      animation-duration: 1s;
+      animation-iteration-count: infinite;
+    }
 
-  ${sx};
-`
+    @media (forced-colors: active) {
+      outline: 1px solid transparent;
+      outline-offset: -1px;
+    }
+
+    ${sx};
+  `,
+)
+
+export const SkeletonBox = React.forwardRef<HTMLDivElement, SkeletonBoxProps>(function SkeletonBox(
+  {height, width, className, style, ...props},
+  ref,
+) {
+  const enabled = useFeatureFlag(CSS_MODULES_FEATURE_FLAG)
+  return (
+    <StyledSkeletonBox
+      height={enabled ? undefined : height}
+      width={enabled ? undefined : width}
+      className={clsx(className, {[classes.SkeletonBox]: enabled})}
+      style={
+        enabled
+          ? merge(
+              style as CSSProperties,
+              {
+                height,
+                width,
+              } as CSSProperties,
+            )
+          : style
+      }
+      {...props}
+      ref={ref}
+    />
+  )
+})

packages/react/src/experimental/Skeleton/SkeletonText.module.css

@@ -0,0 +1,65 @@
+.SkeletonText {
+  --font-size: var(--text-body-size-medium);
+  --line-height: var(--text-body-lineHeight-medium);
+  --leading: calc(var(--font-size) * var(--line-height) - var(--font-size));
+
+  @supports (margin-block: mod(1px, 1px)) {
+    --leading: mod(var(--font-size) * var(--line-height), var(--font-size));
+  }
+
+  height: var(--font-size);
+  border-radius: var(--borderRadius-small);
+  /* stylelint-disable-next-line primer/spacing */
+  margin-block: calc(var(--leading) / 2);
+
+  &:where([data-in-multiline]) {
+    /* stylelint-disable-next-line primer/spacing */
+    margin-block-end: calc(var(--leading) * 2);
+
+    &:last-child {
+      min-width: 50px;
+      max-width: 65%;
+      margin-bottom: 0;
+    }
+  }
+
+  &:where([data-text-skeleton-size='display']),
+  &:where([data-text-skeleton-size='titleLarge']) {
+    border-radius: var(--borderRadius-medium);
+  }
+
+  &:where([data-text-skeleton-size='display']) {
+    --font-size: var(--text-display-size);
+    --line-height: var(--text-display-lineHeight);
+  }
+
+  &:where([data-text-skeleton-size='titleLarge']) {
+    --font-size: var(--text-title-size-large);
+    --line-height: var(--text-title-lineHeight-large);
+  }
+
+  &:where([data-text-skeleton-size='titleMedium']) {
+    --font-size: var(--text-title-size-medium);
+    --line-height: var(--text-title-lineHeight-medium);
+  }
+
+  &:where([data-text-skeleton-size='titleSmall']) {
+    --font-size: var(--text-title-size-small);
+    --line-height: var(--text-title-lineHeight-small);
+  }
+
+  &:where([data-text-skeleton-size='subtitle']) {
+    --font-size: var(--text-subtitle-size);
+    --line-height: var(--text-subtitle-lineHeight);
+  }
+
+  &:where([data-text-skeleton-size='bodyLarge']) {
+    --font-size: var(--text-body-size-large);
+    --line-height: var(--text-body-lineHeight-large);
+  }
+
+  &:where([data-text-skeleton-size='bodySmall']) {
+    --font-size: var(--text-body-size-small);
+    --line-height: var(--text-body-lineHeight-small);
+  }
+}