Release notes for v27?

[dandv]

I know this is in @next stage, but I'm trying to use v27 because Jest ships with jest-circus by default since v27.

The problem is after installing Jest ^27.0.0-next.2 and and "ts-jest": "^27.0.0-next.5", Jest fails with

Cannot use import statement outside a module

My jest.config.cjs is this:

module.exports = {
  preset: 'ts-jest',
  testEnvironment: 'node',
  testRegex: '.*.test.ts',  // test only filenames matching this regex
  moduleFileExtensions: ['ts', 'js'],  // modules are only in .ts files, but 'js' *must* be specified too
};

package.json has "type": "module".

Is there some setting I need to change with moving to v27?

[ahnpnl]

Are you using ESM mode for your tests ? The error said that Jest couldn’t understand your codes. It seems like your codes not transpiled through ts-jest.

[dandv]

Not sure what ESM mode is - where can I read about it? I couldn't find "ESM mode" in the docs.

I haven't changed any mode or settings when I upgraded from v26 to v27.

[ahnpnl]

Hmm sound strange to me that upgrading causes the issue. You didn’t change any configuration either but only upgrade deps ?

Support ESM doc is here https://kulshekhar.github.io/ts-jest/docs/next/guides/esm-support

If only upgrading deps and no configuration changed in your project, it can be either bug in Jest or ts-jest. Perhaps you can check the stack trace or put the stack trace here so it is easier to check.