Use StyleSheet.create in React Native

.changeset/strong-cooks-drum.md

@@ -0,0 +1,7 @@
+---
+'@emotion/native': major
+'@emotion/primitives': major
+'@emotion/primitives-core': major
+---
+
+`StyleSheet.create` is used now under the hood. This means that when used in combination with React Native Web atomic class names are applied on components instead of inline styles.

packages/native/test/__snapshots__/native-styled.test.js.snap

@@ -5,9 +5,7 @@ exports[`Emotion native styled primitive should work with \`withComponent\` 1`]
   decor="hotpink"
   style={
     Array [
-      Object {
-        "color": "hotpink",
-      },
+      77,
       undefined,
     ]
   }
@@ -21,9 +19,7 @@ exports[`Emotion native styled should pass props in withComponent 1`] = `
   color="green"
   style={
     Array [
-      Object {
-        "backgroundColor": "green",
-      },
+      81,
       undefined,
     ]
   }
@@ -35,9 +31,7 @@ exports[`Emotion native styled should pass props in withComponent 2`] = `
   color="hotpink"
   style={
     Array [
-      Object {
-        "backgroundColor": "hotpink",
-      },
+      82,
       undefined,
     ]
   }
@@ -55,12 +49,7 @@ exports[`Emotion native styled should render <Image /> 1`] = `
   }
   style={
     Array [
-      Object {
-        "borderBottomLeftRadius": 2,
-        "borderBottomRightRadius": 2,
-        "borderTopLeftRadius": 2,
-        "borderTopRightRadius": 2,
-      },
+      83,
       undefined,
     ]
   }
@@ -71,9 +60,7 @@ exports[`Emotion native styled should render primitive with style prop 1`] = `
 <Text
   style={
     Array [
-      Object {
-        "color": "hotpink",
-      },
+      77,
       Object {
         "padding": 10,
       },
@@ -89,10 +76,7 @@ exports[`Emotion native styled should render styles correctly from all nested st
   backgroundColor="blue"
   style={
     Array [
-      Object {
-        "backgroundColor": "blue",
-        "color": "hotpink",
-      },
+      86,
       undefined,
     ]
   }
@@ -106,13 +90,7 @@ exports[`Emotion native styled should render the primitive on changing the props
   decor="hotpink"
   style={
     Array [
-      Object {
-        "color": "hotpink",
-        "paddingBottom": 20,
-        "paddingLeft": 20,
-        "paddingRight": 20,
-        "paddingTop": 20,
-      },
+      76,
       undefined,
     ]
   }
@@ -126,11 +104,7 @@ exports[`Emotion native styled should render the primitive when styles applied u
   back="red"
   style={
     Array [
-      Object {
-        "backgroundColor": "red",
-        "color": "red",
-        "fontSize": 20,
-      },
+      74,
       Object {
         "fontSize": 40,
       },
@@ -145,9 +119,7 @@ exports[`Emotion native styled should style any other component 1`] = `
 <Text
   style={
     Array [
-      Object {
-        "color": "hotpink",
-      },
+      77,
       undefined,
     ]
   }
@@ -160,10 +132,8 @@ exports[`Emotion native styled should work with StyleSheet.create API 1`] = `
 <Text
   style={
     Array [
-      Object {
-        "fontSize": 10,
-      },
-      74,
+      79,
+      78,
     ]
   }
 >
@@ -175,9 +145,7 @@ exports[`Emotion native styled should work with theming from @emotion/react 1`]
 <Text
   style={
     Array [
-      Object {
-        "color": "magenta",
-      },
+      75,
       undefined,
     ]
   }

packages/native/test/native-css.test.js

@@ -1,105 +1,134 @@
 import { css } from '@emotion/native'
+import { StyleSheet } from 'react-native'
 
 jest.mock('react-native')
 
 let returnArguments = (...args) => args
 
 describe('Emotion native css', () => {
   test('basic', () => {
-    expect(css`
-      color: hotpink;
-      ${{ backgroundColor: 'green' }};
-    `).toEqual({ color: 'hotpink', backgroundColor: 'green' })
-    expect(css({ color: 'green' })).toEqual({ color: 'green' })
-    expect(css([{ color: 'green' }, `background-color:yellow;`])).toEqual({
+    expect(
+      StyleSheet.flatten(css`
+        color: hotpink;
+        ${{ backgroundColor: 'green' }};
+      `)
+    ).toEqual({ color: 'hotpink', backgroundColor: 'green' })
+    expect(StyleSheet.flatten(css({ color: 'green' }))).toEqual({
+      color: 'green'
+    })
+    expect(
+      StyleSheet.flatten(css([{ color: 'green' }, `background-color:yellow;`]))
+    ).toEqual({
       color: 'green',
       backgroundColor: 'yellow'
     })
-    expect(css([{ color: 'green' }])).toEqual({ color: 'green' })
+    expect(StyleSheet.flatten(css([{ color: 'green' }]))).toEqual({
+      color: 'green'
+    })
   })
 
   test('order with string and object', () => {
     // this test checks the keys instead of the objects
     // because we care about the order of the keys
     expect(
+      // $FlowFixMe
       Object.keys(
-        css({ color: 'green' }, `background-color:yellow;`, { flex: 2 })
+        StyleSheet.flatten(
+          css({ color: 'green' }, `background-color:yellow;`, { flex: 2 })
+        )
       )
     ).toEqual(['color', 'backgroundColor', 'flex'])
     expect(
+      // $FlowFixMe
       Object.keys(
-        css([
-          [{ color: 'green' }, `background-color:yellow;`],
-          {
-            flex: 2
-          }
-        ])
+        StyleSheet.flatten(
+          css([
+            [{ color: 'green' }, `background-color:yellow;`],
+            {
+              flex: 2
+            }
+          ])
+        )
       )
     ).toEqual(['color', 'backgroundColor', 'flex'])
     expect(
+      // $FlowFixMe
       Object.keys(
-        css([
-          { color: 'green' },
-          [
-            `background-color:yellow;`,
-            {
-              flex: 2
-            }
-          ]
-        ])
+        StyleSheet.flatten(
+          css([
+            { color: 'green' },
+            [
+              `background-color:yellow;`,
+              {
+                flex: 2
+              }
+            ]
+          ])
+        )
       )
     ).toEqual(['color', 'backgroundColor', 'flex'])
     expect(
+      // $FlowFixMe
       Object.keys(
-        css([
-          { color: 'green' },
-          [
-            { flex: 8 },
-            `background-color:yellow;`,
-            [`flex-grow: 1;`, { flexDirection: 'row' }]
-          ]
-        ])
+        StyleSheet.flatten(
+          css([
+            { color: 'green' },
+            [
+              { flex: 8 },
+              `background-color:yellow;`,
+              [`flex-grow: 1;`, { flexDirection: 'row' }]
+            ]
+          ])
+        )
       )
     ).toEqual(['color', 'flex', 'backgroundColor', 'flexGrow', 'flexDirection'])
   })
 
   it('allows function interpolations when this.mergedProps is defined', () => {
     expect(
-      css.call({ thing: true }, props => ({
-        color: props.thing && 'hotpink'
-      }))
+      StyleSheet.flatten(
+        css.call({ thing: true }, props => ({
+          color: props.thing && 'hotpink'
+        }))
+      )
     ).toEqual({ color: 'hotpink' })
   })
 
   it('works with nested functions', () => {
     expect(
-      css.call({ thing: true }, props => () => ({
-        color: props.thing && 'hotpink'
-      }))
+      StyleSheet.flatten(
+        css.call({ thing: true }, props => () => ({
+          color: props.thing && 'hotpink'
+        }))
+      )
     ).toEqual({ color: 'hotpink' })
   })
 
   it('works with functions in tagged template literals', () => {
     expect(
-      css.call(
-        {},
-        ...returnArguments`
+      StyleSheet.flatten(
+        css.call(
+          {},
+          ...returnArguments`
         color: ${() => 'hotpink'};
       `
+        )
       )
     ).toEqual({ color: 'hotpink' })
   })
 
   test('last arg falsy and string before that', () => {
-    expect(css('color:hotpink;', false)).toEqual({ color: 'hotpink' })
+    expect(StyleSheet.flatten(css('color:hotpink;', false))).toEqual({
+      color: 'hotpink'
+    })
   })
 
   test('falsy value in the middle', () => {
     expect(
-      css`
+      StyleSheet.flatten(css`
         color: ${false};
         background-color: hotpink;
-      `
+      `)
     ).toEqual({ backgroundColor: 'hotpink' })
   })
 
@@ -108,10 +137,10 @@ describe('Emotion native css', () => {
       color: hotpink;
     `
     expect(
-      css`
+      StyleSheet.flatten(css`
         background-color: green;
         ${firstStyle};
-      `
+      `)
     ).toEqual({ backgroundColor: 'green', color: 'hotpink' })
   })
 
@@ -128,7 +157,7 @@ describe('Emotion native css', () => {
       // color: red;
     `
 
-    expect(styles).toEqual({ color: 'hotpink' })
-    expect(anotherStyles).toEqual({ fontSize: 10 })
+    expect(StyleSheet.flatten(styles)).toEqual({ color: 'hotpink' })
+    expect(StyleSheet.flatten(anotherStyles)).toEqual({ fontSize: 10 })
   })
 })

packages/primitives-core/src/css.js

@@ -7,6 +7,7 @@ import { interleave } from './utils'
 // this is done so we don't create a new
 // handleInterpolation function on every css call
 let styles
+let generated = {}
 let buffer = ''
 let lastType
 
@@ -102,7 +103,14 @@ export function createCss(StyleSheet: Object) {
       buffer = prevBuffer
     }
 
-    return StyleSheet.flatten(styles)
+    const hash = JSON.stringify(styles)
+    if (!generated[hash]) {
+      const styleSheet = StyleSheet.create({
+        generated: StyleSheet.flatten(styles)
+      })
+      generated[hash] = styleSheet.generated
+    }
+    return generated[hash]
   }
 }