refactor and fix linting

types/styled-theming/index.d.ts

@@ -2,9 +2,11 @@
 // Project: https://github.com/styled-components/styled-theming#readme
 // Definitions by: Arjan Jassal <https://github.com/ArjanJ>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
-// TypeScript Version: 3.1.1
+// TypeScript Version: 2.2
 
-declare module "styled-theming" {
+declare function theme(name: string, values: theme.ThemeMap): theme.ThemeSet;
+
+declare namespace theme {
     type ThemeValueFn = (props: object) => string;
     type ThemeValue = string | ThemeValueFn;
 
@@ -19,15 +21,11 @@ declare module "styled-theming" {
     type ThemeSet = (props: object) => string;
     type VariantSet = (props: object) => string;
 
-    namespace theme {
-        export function variants(
-            name: string,
-            prop: string,
-            values: VariantMap
-        ): VariantSet;
-    }
-
-    function theme(name: string, values: ThemeMap): ThemeSet;
-
-    export = theme;
+    function variants(
+        name: string,
+        prop: string,
+        values: VariantMap
+    ): VariantSet;
 }
+
+export default theme;

types/styled-theming/styled-theming-tests.ts

@@ -1,4 +1,4 @@
-import * as theme from "styled-theming";
+import theme from "styled-theming";
 
 const textColor = theme("mode", {
     dark: "white",

types/styled-theming/tsconfig.json

@@ -1,22 +1,16 @@
 {
     "compilerOptions": {
         "module": "commonjs",
-        "lib": [
-            "es6"
-        ],
+        "lib": ["es6"],
         "noImplicitAny": true,
         "noImplicitThis": true,
+        "strictFunctionTypes": true,
         "strictNullChecks": true,
         "baseUrl": "../",
-        "typeRoots": [
-            "../"
-        ],
+        "typeRoots": ["../"],
         "types": [],
         "noEmit": true,
         "forceConsistentCasingInFileNames": true
     },
-    "files": [
-        "index.d.ts",
-        "styled-theming-tests.ts"
-    ]
+    "files": ["index.d.ts", "styled-theming-tests.ts"]
 }