Performance issues when upgrading node-sass version

[mtrajano]

version info:

$ node-sass --version
node-sass 4.12.0  (Wrapper) [JavaScript]
libsass   3.5.4 (Sass Compiler) [C/C++]

Description:

Sorry if this has already been reported. Background: We run an application where we do a lot of sass compilations. When upgrading our systems to node v12.12.0 along with node-sass 4.12.0 we noticed a decent performance degradation. Our response times nearly doubled, from an average of 60ms to an average of 100ms (see chart below, upgrade went out around 10/22):

We pinpointed the performance issue to node-sass and when we rolled back the version to 4.6.1 (libsass version: 3.5.0.beta.2) we noticed the response times going back to normal levels (rollback went out around 1:30pm):

Let me know if I should direct this issue to the node-sass repo instead. Thank you ahead of time and let me know if you need any more info from us!

[mgreter]

I guess it could be libsass or node-sass. If you can run both libsass versions with sassc directly we could maybe get some answer. But this seems irrelevant (at least for libsass) given the latest work I've done in #2918 (and some numbers I gave in sass/sass#2737). Long story short, performance should be greatly improved again with latest refactoring for libsass 4.x (ETA for when it's really ready unknown), so we probably won't address this in another libsass 3.x release. But feel free to test if you can, if it is a case for node-sass they're probably interested to know about it to be able to solve it.