Diagnostics Uses a Huge Amount of Memory

[mattyclarkson]

• Issue

Running the tests without a populated cache uses a huge amount of memory and time. I am seeing >2mins vs 10seconds on ef-carbon/dom

It seems the first workers that spawn crush somehow. Notice that the first 8 tests took 80seconds and then the rest passed in a few seconds.

 PASS  test/visit.test.ts (79.523s)
 PASS  test/node/Audio.test.ts (79.62s)
 PASS  test/node/Container.test.ts (79.799s)
 PASS  test/node/Video.test.ts (80.375s)
 PASS  test/node/Scrollable.test.ts (80.874s)
 PASS  test/node/Modal.test.ts (81.261s)
 PASS  test/walk.test.ts (81.819s)
 PASS  test/node/Text.test.ts
 PASS  test/node/Link.test.ts
 PASS  test/node/Span.test.ts
 PASS  test/node/Padding.test.ts
 PASS  test/node/List.test.ts
 PASS  test/node/Heading.test.ts
 PASS  test/node/Carousel.test.ts
 PASS  test/node/Image.test.ts
 PASS  test/node/Quote.test.ts
 PASS  test/node/Code.test.ts
 PASS  test/node/Separator.test.ts

• Expected behavior

That the diagnostics should add a small overhead

• Output from your debug log
  [ You can activate the debug logger by setting the environment variable TS_JEST_DEBUG="true" before running yarn test. The output of the logger
  will be in <your_project_dir>/node_modules/ts-jest/debug.txt ]

debug.txt

• Link to a minimal repo that reproduces this issue

$ git clone https://github.com/ef-carbon/dom.git
$ yarn install
$  # Run tests with diagnostics (~4mins)
$ yarn test --clearCache
$ yarn test
$ jq '.jest.globals["ts-jest"].enableTsDiagnostics = false' < package.json > package.json~
$ mv package.json{~,}
$  # Run tests without diagnostics (~10secs)
$ yarn test --cleanCache
$ yarn test

[kulshekhar]

I'm not sure what the cause of this could be - mostly because I never use diagnostics with ts-jest (I run diagnostics during dev and in the CI process). This feature was only added because a lot of folks wanted it.

That said, if you can create a minimal repo that reproduces this, I'll take a look at this when I next have some time using the repo you've linked to

[kulshekhar]

I've just taken a look at this and I'm not sure there's anything that can be done in ts-jest to fix this.

A better option might be to to run check for type errors separately (that's what I personally do).

[mattyclarkson]

We actually run tslint and tsc with strict checks. I've now disabled the diagnostics on our CI. They still pick up things locally that the other two don't, somehow.

[kulshekhar]

They still pick up things locally that the other two don't, somehow.

I'm not sure I understand 😕
If anything, I'd expect ts-jest's output (diagnostic related) to be a subset of what tsc would show

[kulshekhar]

I've added an additional note related to this: https://github.com/kulshekhar/ts-jest#ts-compiler--error-reporting

That doesn't solve this problem but it has been put there to make users aware of the issue in advance. Ideally, type errors should be checked in a different step and not as part of testing.

[huafu]

You can try beta version which addresses this issue (see #697). Don't forget to activate type-checking and other diagnostic relevant options. They are not documented yet in beta, but here is something that might help until then (jest.globals.ts-jest config)

Update: Type-checking is enabled by default now. See readme for the link to documentation.