Add @styled-system/core typings (#45332)

* Added @styled-system/core typings

* fixed path in tsconfig

* added csstype to package.json

* changed project url

types/styled-system__core/index.d.ts

@@ -0,0 +1,50 @@
+// Type definitions for @styled-system/core 5.1
+// Project: https://github.com/styled-system/styled-system
+// Definitions by: Leo Toneff <https://github.com/bragle>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 3.1
+
+import * as CSS from 'csstype';
+
+export function get(obj: any, ...paths: Array<string | number>): any;
+
+export type ObjectOrArray<T, K extends keyof any = keyof any> = T[] | Record<K, T | Record<K, T> | T[]>;
+
+export type Scale = ObjectOrArray<number | string>;
+
+export interface styleFn {
+    (...args: any[]): any;
+
+    config?: object;
+    propNames?: string[];
+    cache?: object;
+}
+
+export interface ConfigStyle {
+    /** The CSS property to use in the returned style object (overridden by `properties` if present). */
+    property?: keyof CSS.Properties;
+    /**
+     * An array of multiple properties (e.g. `['marginLeft', 'marginRight']`) to which this style's value will be
+     * assigned (overrides `property` when present).
+     */
+    properties?: Array<keyof CSS.Properties>;
+    /** A string referencing a key in the `theme` object. */
+    scale?: string;
+    /** A fallback scale object for when there isn't one defined in the `theme` object. */
+    defaultScale?: Scale;
+    /** A function to transform the raw value based on the scale. */
+    transform?: (value: any, scale?: Scale) => any;
+}
+
+export interface Config {
+    /** Property name exposed for use in components */
+    [customStyleName: string]: ConfigStyle | boolean;
+}
+
+export function compose(...parsers: styleFn[]): styleFn;
+
+export function system(styleDefinitions: Config): styleFn;
+
+export function createParser(config: ConfigStyle): styleFn;
+
+export function createStyleFunction(args: ConfigStyle): styleFn;

types/styled-system__core/package.json

@@ -0,0 +1,6 @@
+{
+    "private": true,
+    "dependencies": {
+        "csstype": "^2.6.10"
+    }
+}

types/styled-system__core/styled-system__core-tests.ts

@@ -0,0 +1,19 @@
+import { compose, system, get } from '@styled-system/core';
+
+// Test that the system definition is correct.
+// https://github.com/styled-system/styled-system/blob/master/packages/core/src/index.js#L131
+const customFontStyles = system({
+    fontWeight: {
+        property: 'fontWeight',
+        properties: ['fontWeight'],
+        scale: 'fontWeights',
+        defaultScale: [200, 400, 600],
+        transform: (n, scale) => get(scale, n),
+    },
+    letterSpacing: true,
+});
+
+const CustomFontGroup = compose(
+    customFontStyles,
+    customFontStyles
+);

types/styled-system__core/tsconfig.json

@@ -0,0 +1,19 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": ["es6"],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictFunctionTypes": true,
+        "strictNullChecks": true,
+        "baseUrl": "../",
+        "typeRoots": ["../"],
+        "paths": {
+            "@styled-system/core": ["styled-system__core"]
+        },
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": ["index.d.ts", "styled-system__core-tests.ts"]
+}

types/styled-system__core/tslint.json

@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }