initial commit on github

src/classNames.ts

@@ -0,0 +1,31 @@
+export interface ObjectClassNames {
+    [index: string]: boolean;
+}
+
+export type ClassName = number | string | ObjectClassNames | false | null | undefined;
+
+export default function classNames(...classNames: ClassName[]) {
+    let result: string[] = [];
+
+    classNames.forEach((item: ClassName): void => {
+        if(!item) {
+            return;
+        }
+        switch(typeof item) {
+            case 'string':
+                result.push(item);
+                break;
+            case 'object':
+                Object.keys(item).forEach((key: string) => {
+                    if(item[key]) {
+                        result.push(key);
+                    }
+                });
+                break;
+            default:
+                result.push(`${item}`);
+        }
+    });
+
+    return result.join(' ');
+}