ts-jest with cleared cache is reading package.json in node_modules over and over - start takes forever

[Farbdose]

Bug Report

I just updated to ts-jest@23.10.5 from somewhere around ~23.1.3 which increased the runtime of my test suite from 10ish seconds [on the first run / with cleared cache] to over 40 seconds - with cache around 2.5s.

It's possible that this is a ts-jest (or even typescript) issue BUT after I created a demo-repository I realized that the problem went away after I removed ionic from the project.
So ionic probably has something to do with it.

Ionic version:

[x] 4.x

Current behavior:
The initial start of jest takes around 30 seconds on an almost empty repository with ionic included.

Expected behavior:
The initial start of jest shouldn't take that long.

Steps to reproduce:

• Have js files that need to be processed by ts-jest (as they contain import statements) being present in one of the modules you import
• have ts-jest@>=23.10.1
• import the IonicModule in one of you angular modules

Related code:
https://gitlab.com/Farbdose/ts-jest-multiple-fileread

git clone git@gitlab.com:Farbdose/ts-jest-multiple-fileread.git
npm install && npm run test

Other information:

You can find the original issue at kulshekhar/ts-jest#908
Possibly related #15695: I had to use the fix described there to actually get jest running at all.

Ionic info:

[WARN] You are not in an Ionic project directory. Project context may be missing.

Ionic:

   ionic (Ionic CLI) : 4.3.1

System:

   NodeJS : v8.11.2
   npm    : 6.1.0
   OS     : Linux 4.15

[Farbdose]

Update: I played a bit around and wrote a very basic [destructive] cache into getPackageJsonInfo see here ...which got the time down to around 24s again.

The interesting thing though is, that after that I got a much clearer cpu profile:
CPU-20181218T162138.zip

[Farbdose]

Update2: I updated the demo repository to ionic 4.0.0-rc.0 and typescript to 3.2.2.

It now takes around 45 seconds in the gitlab build pipeline so if anybody wants to try his luck, you are welcome.

[Farbdose]

Update3: @paulstelzer This was caused by a combination of uncached file reads and now by default enabled language services in ts-jest. It has nothing to do with ionic, ionic was just the package with the most require-statements / separate modules in node_modules.

[paulstelzer]

so this can be closed now?

[Farbdose]

@paulstelzer yes

[paulstelzer]

Thank you for the resarch :)

[Farbdose]

@paulstelzer I think the only thing you could have realistically done is what you alread did: remove the icons from the build chain. ts-jest was probably reading the package.json again and again for each icon...

[ionitron-bot]

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