This repo was created to expose the memory issue with jest in the latest version of node.
When using jest with node 16.11+, the memory usage can easily go out of control even for very simple test suites like those used in this repo.
Note: This fork uses Volta for running tests with differnent node versions. See relevant documentation here.
Test Suites: 100 total
Tests: 100000 total
| Node | Jest | config | heap MB (Δ) | time secs |
|---|---|---|---|---|
| 14.20 | 28.1.3 | 40 -> 646 (606) | 37.9 | |
| 14.20 | 29.0.3 | 46 -> 418 (372) | 40.26 | |
| 14.20 | 29.0.3 | expose-gc | 25 -> 86 (61) | 50.7 |
| 16.10 | 29.0.3 | 54 -> 379 (325) | 40.81 | |
| 16.16 | 28.1.3 | 40 -> 896 (856) | 47.46 | |
| 16.16 | 29.0.3 | 46 -> 819 (773) | 50.72 | |
| 16.16 | 29.0.3 | expose-gc | 28 -> 356 (328) | 72.86 |
- Jest 29 seems to have reduced memory leaks although increasing run time.
- Node 16 has increased the leaked memory since 16.10.
expose-gcallows Jest to trigger the node CG after each test. Node optimises performance by using a large heap old-space - sacrificing memory use to get speed. Therefore we would expect using theexpose-gcflag would result in a smaller heap delta but an increased run time.