feat: deprecate vars(). Add <VariableContextProvider /> (#131)

Author: marklawlor

src/__tests__/native/variables.test.tsx

@@ -4,7 +4,7 @@ import type { ViewProps } from "react-native";
 import { render, screen } from "@testing-library/react-native";
 import { View } from "react-native-css/components/View";
 import { registerCSS, testID } from "react-native-css/jest";
-import { styled } from "react-native-css/runtime";
+import { styled, VariableContextProvider } from "react-native-css/runtime";
 
 test("inline variable", () => {
   registerCSS(`.my-class { width: var(--my-var); --my-var: 10px; }`);
@@ -230,3 +230,18 @@ test("ratio values", () => {
 
   expect(component.props.style).toStrictEqual({ aspectRatio: "16 / 9" });
 });
+
+test("VariableContextProvider", () => {
+  registerCSS(`
+    .test { color: var(--my-var); }
+  `);
+
+  render(
+    <VariableContextProvider value={{ "--my-var": "red" }}>
+      <View testID={testID} className="test" />
+    </VariableContextProvider>,
+  );
+
+  const component = screen.getByTestId(testID);
+  expect(component.props.style).toStrictEqual({ color: "red" });
+});

src/__tests__/native/vars.test.tsx

@@ -1,3 +1,4 @@
+/* eslint-disable @typescript-eslint/no-deprecated */
 import { render, screen } from "@testing-library/react-native";
 import { View } from "react-native-css/components/View";
 import { registerCSS, testID } from "react-native-css/jest";

src/runtime/native/api.ts src/runtime/native/api.tsxsrc/runtime/native/api.ts renamed to src/runtime/native/api.tsx

@@ -1,8 +1,8 @@
 /* eslint-disable  */
-import { useContext, useState } from "react";
+import { useContext, useMemo, useState, type PropsWithChildren } from "react";
 import { Appearance } from "react-native";
 
-import type { InlineVariable, StyleDescriptor } from "../../compiler";
+import type { StyleDescriptor } from "../../compiler";
 import type {
   ColorScheme,
   Props,
@@ -18,6 +18,7 @@ import {
   VariableContext,
   type Effect,
   type Getter,
+  type VariableContextValue,
 } from "./reactivity";
 import { resolveValue } from "./styles/resolve";
 
@@ -102,7 +103,33 @@ export function useNativeVariable(name: string) {
   return resolveValue([{}, "var", [name]], effect.get, { inheritedVariables });
 }
 
+/**
+ * @deprecated Use `<VariableContextProvider />` instead.
+ */
 export function vars(variables: Record<string, StyleDescriptor>) {
-  (variables as InlineVariable)[VAR_SYMBOL] = "inline";
-  return variables;
+  return Object.assign(
+    { [VAR_SYMBOL]: "inline" },
+    Object.fromEntries(
+      Object.entries(variables).map(([k, v]) => [k.replace(/^--/, ""), v]),
+    ),
+  );
+}
+
+export function VariableContextProvider(
+  props: PropsWithChildren<{ value: Record<`--${string}`, StyleDescriptor> }>,
+) {
+  const inheritedVariables = useContext(VariableContext);
+
+  const value: VariableContextValue = useMemo(
+    () => ({
+      ...inheritedVariables,
+      ...Object.fromEntries(
+        Object.entries(props.value).map(([k, v]) => [k.replace(/^--/, ""), v]),
+      ),
+      [VAR_SYMBOL]: true,
+    }),
+    [inheritedVariables, props.value],
+  );
+
+  return <VariableContext value={value}>{props.children}</VariableContext>;
 }

src/runtime/web/api.ts src/runtime/web/api.tsxsrc/runtime/web/api.ts renamed to src/runtime/web/api.tsx

@@ -1,4 +1,9 @@
-import { createElement, type ComponentProps } from "react";
+import {
+  createElement,
+  useMemo,
+  type ComponentProps,
+  type PropsWithChildren,
+} from "react";
 import { Appearance } from "react-native";
 
 import type {
@@ -24,7 +29,7 @@ export const styled = <
   };
 };
 
-export const useCssElement = <const C extends ReactComponent>(
+export const useCssElement = <C extends ReactComponent>(
   component: C,
   incomingProps: Props,
   mapping: StyledConfiguration<C>,
@@ -66,6 +71,9 @@ export const colorScheme: ColorScheme = {
   },
 };
 
+/**
+ * @deprecated Use `<VariableContextProvider />` instead.
+ */
 export function vars(variables: Record<string, string | number>) {
   const $variables: Record<string, string> = {};
 
@@ -79,6 +87,24 @@ export function vars(variables: Record<string, string | number>) {
   return $variables;
 }
 
+export function VariableContextProvider(
+  props: PropsWithChildren<{ value: Record<`--${string}`, string> }>,
+) {
+  const style = useMemo(() => {
+    return {
+      display: "content",
+      ...Object.fromEntries(
+        Object.entries(props.value).map(([key, value]) => [
+          key.startsWith("--") ? key : `--${key}`,
+          value,
+        ]),
+      ),
+    };
+  }, [props.value]);
+
+  return <div style={style}>{props.children}</div>;
+}
+
 export const useNativeVariable = () => {
   throw new Error("useNativeVariable is not supported in web");
 };