| 29 | // infinite change detection cycles where the change detection updates a comment, triggering the |
| 30 | // MutationObserver, triggering another change detection and kicking the cycle off again. |
| 31 | function shouldIgnoreRecord(record: MutationRecord) { |
| 32 | // Ignore changes to comment text. |
| 33 | if (record.type === 'characterData' && record.target instanceof Comment) { |
| 34 | return true; |
| 35 | } |
| 36 | // Ignore addition / removal of comments. |
| 37 | if (record.type === 'childList') { |
| 38 | for (let i = 0; i < record.addedNodes.length; i++) { |
| 39 | if (!(record.addedNodes[i] instanceof Comment)) { |
| 40 | return false; |
| 41 | } |
| 42 | } |
| 43 | for (let i = 0; i < record.removedNodes.length; i++) { |
| 44 | if (!(record.removedNodes[i] instanceof Comment)) { |
| 45 | return false; |
| 46 | } |
| 47 | } |
| 48 | return true; |
| 49 | } |
| 50 | // Observe everything else. |
| 51 | return false; |
| 52 | } |
| 53 | |
| 54 | /** |
| 55 | * Factory that creates a new MutationObserver and allows us to stub it out in unit tests. |