| 32 | * Note: if two objects have the same property the last one wins |
| 33 | */ |
| 34 | export function extend(...objects: (NestedCSSProperties | undefined | null | false)[]): NestedCSSProperties { |
| 35 | /** The final result we will return */ |
| 36 | const result: CSSProperties & Record<string, any> = {}; |
| 37 | for (const object of objects) { |
| 38 | if (object == null || object === false) { |
| 39 | continue; |
| 40 | } |
| 41 | for (const key in object) { |
| 42 | |
| 43 | /** Falsy values except a explicit 0 is ignored */ |
| 44 | const val: any = (object as any)[key]; |
| 45 | if (!val && val !== 0) { |
| 46 | continue; |
| 47 | } |
| 48 | |
| 49 | /** if nested media or pseudo selector */ |
| 50 | if (key === '$nest' && val) { |
| 51 | result[key] = result['$nest'] ? extend(result['$nest'], val) : val; |
| 52 | } |
| 53 | /** if freestyle sub key that needs merging. We come here due to our recursive calls */ |
| 54 | else if ((key.indexOf('&') !== -1 || key.indexOf('@media') === 0)) { |
| 55 | result[key] = result[key] ? extend(result[key], val) : val; |
| 56 | } |
| 57 | else { |
| 58 | result[key] = val; |
| 59 | } |
| 60 | } |
| 61 | } |
| 62 | |
| 63 | return result; |
| 64 | } |
| 65 | |
| 66 | |
| 67 | /** |