wehub-resource-sync
30 lines
1.2 KiB
Markdown
30 lines
1.2 KiB
Markdown
# Using Memlab
|
|
|
|
[Memlab](https://facebook.github.io/memlab/) is an E2E testing and analysis framework for finding JavaScript memory leaks.
|
|
|
|
## Important Rule
|
|
|
|
**NEVER read raw `.heapsnapshot` files directly.** They are too large and will exceed context limits. Always use `memlab` commands to analyze them.
|
|
|
|
## Analyzing Snapshots
|
|
|
|
You can use the `take_heapsnapshot` tool provided by the `chrome-devtools-mcp` extension to generate heap snapshots during an investigation. To find leaks, you generally need 3 snapshots:
|
|
|
|
1. **Baseline:** Before the suspect action.
|
|
2. **Target:** After the suspect action.
|
|
3. **Final:** After reverting the suspect action (e.g., closing a modal, navigating away).
|
|
|
|
Once you have these 3 snapshots saved to disk, you can use `memlab` to find leaks:
|
|
|
|
```bash
|
|
npx memlab find-leaks --baseline <path-to-baseline> --target <path-to-target> --final <path-to-final>
|
|
```
|
|
|
|
You can also parse a single snapshot to find the largest objects or explore it individually:
|
|
|
|
```bash
|
|
npx memlab analyze snapshot --snapshot <path-to-snapshot>
|
|
```
|
|
|
|
Memlab will output the retainer traces for identified leaks. Use these traces to guide your search in the codebase.
|