Ts-jest breaks when using native Big Integers

[orbmis]

🐛 Bug Report

When running unit tests on a module that uses native JavaScript bigints, the following error is generated:

SyntaxError: /calculate.ts: Identifier directly after number (8:18)

    >  8 | const EXPONENT = 5n;

To Reproduce

Steps to reproduce the behavior:

Run any test that declares a native JavaScript bigint, e.g.:

const someValue = 3n

Expected behavior

Expected tests to handle native JavaScript bigint types. When running and building the application, bigints don't pose a problem.

Link to repo (highly encouraged)

Debug log:

The stacktrace seems to point to babel as the cuprit:

at Parser._raise (node_modules/@babel/parser/src/parser/location.js:233:45)
      at Parser.raiseWithData (node_modules/@babel/parser/src/parser/location.js:228:17)
      at Parser.raise (node_modules/@babel/parser/src/parser/location.js:212:17)
      at Parser.readNumber (node_modules/@babel/parser/src/tokenizer/index.js:1092:18)
      at Parser.getTokenFromCode (node_modules/@babel/parser/src/tokenizer/index.js:752:14)
      at Parser.nextToken (node_modules/@babel/parser/src/tokenizer/index.js:240:12)
      at Parser.next (node_modules/@babel/parser/src/tokenizer/index.js:154:10)
      at Parser.eat (node_modules/@babel/parser/src/tokenizer/index.js:161:12)
      at Parser.parseVar (node_modules/@babel/parser/src/parser/statement.js:974:16)
      at Parser.parseVarStatement (node_modules/@babel/parser/src/parser/statement.js:688:10)

envinfo

System:
    OS: MacOS Mojave 10.14.6

Npm packages:
    jest: ^25.1.0
    ts-jest: ^25.2.1
    typescript: ^3.8.3
    babel(optional): ^7.8.7
    babel-typescript: ^7.8.3

[orbmis]

Just to update: the problem seems to be explicitly with collecting coverage, if I exclude the specified file from coverage collection, the error disappears. However, I found an easy workaround in using the following syntax:

const someValue = BigInt(3)

instead of:

const someValue = 3n

Using this workaround works perfectly for me, with caveats for other developers obviously, so I'm happy to close to the issue if you feel that's suitable.

[ahnpnl]

I think jestjs/jest#9774 fixed your issue, which is available in jest 25.3

I will close the issue as not ts-jest problem :)

[orbmis]

Thanks @ahnpnl