Breaking changes: pathsToModuleNameMapper resolve path mapping with path.join

[splincode]

🐛 Bug Report

@ahnpnl Hi, I see this PR
#1969

But this incorrect work when we usage parent directory
After upgrade my test failed
Angular-RU/sdk#172

To Reproduce

we usage ../ in paths

{
    "compilerOptions": {
        "rootDir": ".",
        "baseUrl": "./",
        "module": "esnext",
        "outDir": "./dist/out-tsc",
        "target": "es5",
        "typeRoots": ["../../node_modules/@types", "./"],
        "lib": ["es2018", "dom"],
        "paths": {
            "@angular-ru/logger": ["dist/library"],
            "@angular-ru/common": ["../common/dist/library"],
            "@angular-ru/common/*": ["../common/dist/library/*"]
        }
    }
}

My test for correct behavior work with pathsToModuleNameMapper (ts-jest < 26.4.0):
https://github.com/Angular-RU/angular-ru-sdk/blob/master/packages/jest-utils/integration/tests/simple.spec.ts#L36

Expected behavior

https://github.com/kulshekhar/ts-jest/pull/1969/files#diff-0896c7082173d4fb5357a023b5205b17R10

could you add another test?

https://github.com/Angular-RU/angular-ru-sdk/blob/master/packages/jest-utils/tsconfig.json#L14
where are you referring to the parent directory?

[splincode]

Also repro:

$ git clone https://github.com/Angular-RU/angular-ru-sdk.git
$ cd angular-ru-sdk
$ yarn install
$ cd packages/jest-utils/
$ # edit package.json (update to ts-jest 26.4.0)
$ yarn build:lib
$ yarn test # see debug

Expected

[DEBUG]:  {
    "^@mock/(.*)$": "<rootDir>/integration/tests/helpers/$1",
    "^@angular\\-ru/common$": "<rootDir>/../common/dist/library",
    "^@angular\\-ru/common/(.*)$": "<rootDir>/../common/dist/library/$1"
} 

[ahnpnl]

hi, thank you for your report. I will look into it. Apparently it is a regression

[ahnpnl]

Hmm do you think we can have a logic that, if path starts with . (like your case) then simply append path (which is in 26.3.0), otherwise use path.join

It looks to me like the problem with #1968 only happens when the path doesn’t start with .

[splincode]

@ahnpnl It looks to me like the problem with #1968 only happens when the path doesn’t start with .

not sure, but if we will have test for this case then I would be sure of it

[ahnpnl]

hi @splincode , I have published 26.4.1-alpha.0. Would you please try and see if it fixes the issue ? You can try this alpha version when installing ts-jest@next

[splincode]

thank you 🙏 I will try latter