Very high memory usage

[mvestergaard]

I've been having issues with the typescript compiler eating up lots of memory.

A run of tsc in my current project reaches around 1.1-1.2GB memory before completion.

This has been causing issues when using awesome-typescript-loader through webpack. It actually crashes after a little while because it exceeds a memory limit (1.5GB i believe)
This seems to be caused in part by a memory leak in ATL, but the memory use of tsc on its own is bordering on extreme.
I have an issue open on that project as well s-panferov/awesome-typescript-loader#227

I would suspect however, that with a project large enough, tsc could exceed the memory limit on its own.

I can provide an example project if needed.

Node: 6.5.0
TS: 2.0.2

[mhegazy]

can you try typescript@next and see if the issue persists?

[vladima]

yes please, repro project will definitely be very helpful

[mvestergaard]

@mhegazy appears to be the same with typescript@next

@vladima [removed - use gist from ChrisJamesC below]
npm install && typings install then npm start or tsc

npm start uses awesome-typescript-loader as described, it should most likely crash with an out of memory error if you leave it be a while, you may need to do an edit to a file though to cause a re-build... Keep an eye on the memory, it should keep climbing.

[mvestergaard]

Odd thing is, running my tests with npm t both runs faster, and doesn't use very much memory.
The tests run through ts-node. Not sure what that project does differently.

[vladima]

repro can be narrowed down to typings for enzyme, seems that most of the compilation time/memory is spent there

vladima@vladima-W520:~/sources/playground/enzyme-test$ node_modules/.bin/tsc --diagnostics --listFiles node_modules/@types/enzyme/index.d.ts 
/home/vladima/sources/playground/enzyme-test/node_modules/typescript/lib/lib.d.ts
/home/vladima/sources/playground/enzyme-test/node_modules/@types/react/index.d.ts
node_modules/@types/enzyme/index.d.ts
Files:              3
Lines:          22201
Nodes:         106921
Identifiers:    39075
Symbols:      1126162
**Types:         937485**
**Memory used: 1104806K**
I/O read:       0.00s
I/O write:      0.00s
Parse time:     0.26s
Bind time:      0.19s
Check time:    13.42s
Emit time:      0.01s
Total time:    13.88s
vladima@vladima-W520:~/sources/playground/enzyme-test$ popd
~/sources/playground/10719/product-designer
vladima@vladima-W520:~/sources/playground/10719/product-designer$ node_modules/.bin/tsc --diagnostics -p .
Files:             112
Lines:           55706
Nodes:          203971
Identifiers:     78405
Symbols:       1157256
**Types:          949701**
**Memory used:  1083038K**
I/O read:        0.01s
I/O write:       0.01s
Parse time:      0.62s
Bind time:       0.43s
Check time:     16.10s
Emit time:       0.36s
Total time:     17.51s
vladima@vladima-W520:~/sources/playground/10719/product-designer$ 

[mvestergaard]

@vladima Do you have any ideas yet which part of the enzyme types may be causing this? I'm wondering if there's any kind of temporary work around i could implement, since this is kind of a show stopper for me atm.

[mvestergaard]

I've done a bit of digging on my own.
It appears it has something to do with overloads, and possibly generics.

Commenting out this block from CommonWrapper saves about 270MB memory:

    parents<P2>(component: ComponentClass<P2>): CommonWrapper<P2, any>;
    parents<P2>(statelessComponent: StatelessComponent<P2>): CommonWrapper<P2, {}>;
    parents(props: EnzymePropSelector): CommonWrapper<any, any>;
    parents(selector: string): CommonWrapper<HTMLAttributes<{}>, any>;
    parents(): CommonWrapper<any, any>;

Commenting out other similar blocks give similar results more or less.

[mvestergaard]

Usage of StatelessComponent seems to be the main cause.
Removing all usages of that from the enzyme type brought memory usage down from a little over 1GB to around 300MB. There must be other things too because excluding the enzyme type entirely brings it down to 158MB.

[MastroLindus]

I have the same exact issues in the typescript@next version.
Compiling my project takes normally less than 2 seconds.
If I just add a import {shallow} from 'enzyme' compilation time spikes to 20 seconds.
Using webpack + tsloader, but even by invoking tsc directly I can see the difference in time.
tsc -w just gets me a heap out of memory error.

[MastroLindus]

By the way I downgraded to 1.8.10 and adding or removing enzyme doesn't affect so much my building time (around 2seconds in both scenarios).

It's really with the 2.1.x version that it gets 10 times slower and the memories usage goes to the roof, and it is a shame since I am in love with most of the features in the 2.x branch