Added basic support for accepting custom shouldForwardProp option in React Native related packages.

.changeset/wicked-mails-obey.md

@@ -0,0 +1,6 @@
+---
+'@emotion/native': minor
+'@emotion/primitives': minor
+---
+
+Added basic support for accepting custom `shouldForwardProp` option.

packages/primitives-core/src/styled.js

@@ -1,23 +1,35 @@
 // @flow
 import * as React from 'react'
-import { testAlwaysTrue, pickAssign, interleave } from './utils'
+import { interleave } from './utils'
 import { ThemeContext } from '@emotion/core'
 import { createCss } from './css'
 
-let defaultPickTest = prop => prop !== 'theme'
+let testOmitPropsOnComponent = prop => prop !== 'theme'
 
-type options = {
+type CreateStyledOptions = {
   getShouldForwardProp: (cmp: React.ElementType) => (prop: string) => boolean
 }
 
+type StyledOptions = {
+  shouldForwardProp?: (prop: string) => boolean
+}
+
 export function createStyled(
   StyleSheet: Object,
-  { getShouldForwardProp = () => defaultPickTest }: options = {}
+  {
+    getShouldForwardProp = () => testOmitPropsOnComponent
+  }: CreateStyledOptions = {}
 ) {
   const css = createCss(StyleSheet)
 
-  return function createEmotion(component: React.ElementType) {
-    let pickTest = getShouldForwardProp(component)
+  return function createEmotion(
+    component: React.ElementType,
+    options?: StyledOptions
+  ) {
+    let shouldForwardProp =
+      options && options.shouldForwardProp
+        ? options.shouldForwardProp
+        : getShouldForwardProp(component)
 
     return function createStyledComponent(...rawStyles: *) {
       let styles
@@ -31,22 +43,34 @@ export function createStyled(
       // do we really want to use the same infra as the web since it only really uses theming?
       // $FlowFixMe
       let Styled = React.forwardRef((props, ref) => {
-        let mergedProps = pickAssign(testAlwaysTrue, {}, props, {
-          theme: props.theme || React.useContext(ThemeContext)
-        })
+        let mergedProps = props
+        if (props.theme == null) {
+          mergedProps = {}
+          for (let key in props) {
+            mergedProps[key] = props[key]
+          }
+          mergedProps.theme = React.useContext(ThemeContext)
+        }
+
         let stylesWithStyleProp = styles
         if (props.style) {
           stylesWithStyleProp = styles.concat(props.style)
         }
         const emotionStyles = css.apply(mergedProps, stylesWithStyleProp)
 
-        return React.createElement(
-          component,
-          pickAssign(pickTest, {}, props, {
-            ref: ref,
-            style: emotionStyles
-          })
-        )
+        let newProps = {}
+
+        for (let key in props) {
+          if (shouldForwardProp(key)) {
+            newProps[key] = props[key]
+          }
+        }
+
+        newProps.style = emotionStyles
+        newProps.ref = ref
+
+        // $FlowFixMe
+        return React.createElement(component, newProps)
       })
       // $FlowFixMe
       Styled.withComponent = (newComponent: React.ElementType) =>

packages/primitives-core/src/utils.js

@@ -1,26 +1,5 @@
 // @flow
 
-export const testAlwaysTrue = () => true
-
-export const pickAssign: (
-  testFn: (key: string) => boolean,
-  target: {},
-  ...sources: Array<{}>
-) => Object = function(testFn, target) {
-  let i = 2
-  let length = arguments.length
-  for (; i < length; i++) {
-    let source = arguments[i]
-    let key
-    for (key in source) {
-      if (testFn(key)) {
-        target[key] = source[key]
-      }
-    }
-  }
-  return target
-}
-
 export function interleave(vals: Array<*>) {
   let strings = vals[0]
   let finalArray = [strings[0]]

packages/primitives/test/__snapshots__/emotion-primitives.test.js.snap

@@ -1,5 +1,17 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`Emotion primitives custom shouldForwardProp works 1`] = `
+<Text
+  style={
+    Object {
+      "color": "hotpink",
+    }
+  }
+>
+  Emotion
+</Text>
+`;
+
 exports[`Emotion primitives primitive should work with \`withComponent\` 1`] = `
 <Text
   style={

packages/primitives/test/emotion-primitives.test.js

@@ -186,4 +186,20 @@ describe('Emotion primitives', () => {
 
     expect(tree).toMatchSnapshot()
   })
+
+  test('custom shouldForwardProp works', () => {
+    const Text = styled.Text``
+    const Title = props => <Text {...props} />
+    // $FlowFixMe
+    const StyledTitle = styled(Title, {
+      shouldForwardProp: prop => prop !== 'color' && prop !== 'theme'
+    })`
+      color: ${props => props.color};
+    `
+
+    const tree = renderer
+      .create(<StyledTitle color="hotpink">{'Emotion'}</StyledTitle>)
+      .toJSON()
+    expect(tree).toMatchSnapshot()
+  })
 })