deepdash-es not working with jest-resolve

[jonnytest1]

i did some debugging and the jest-resolve => resolve.exports package expects each export to have a 3rd field either "default" "require" or "browser"

[Julian-B90]

I have the same error Cannot find module 'deepdash-es/omitDeep' from

[rommni]

Same error here, someone has an idea how to fix this ?

[jonnytest1]

something along the lines of this in the jest-setup.js should work

const packageJsonPath = join(__dirname, 'node_modules/deepdash-es/package.json');
const packageJson = JSON.parse(readFileSync(packageJsonPath, { encoding: 'utf8' }));

// fix package.json

writeFileSync(packageJsonPath, JSON.stringify(packageJson, undefined, '  '));

[Dinika]

@jonnytest1 The above does not work in non-nodejs environments, right? At least I get the following errors:

ReferenceError: join is not defined                                // I fixed this by using Array.prototype.join
ReferenceError: readFileSync is not defined

I also don't completely understand the solution. It seems to me we are trying to change the contents of package.json file for deepdash-es module, which looks a bit hacky. Is there a better, more official way of handling this?

[Dinika]

My work around for the issue was the following:

// jest.config.js

  moduleNameMapper: {
    ... other mapping,
    'deepdash-es': '<rootDir>/global.mock.js', 
  },

// global.mock.js

// Mock implementations for deepdash-es functions being used by the component under test 
export const findDeep = (flatTree, findFn) => flatTree.find(findFn);
export const reduceDeep = (arr) => arr;

Obviously, the work-around is not great because it requires overriding functionality provided by this library that the component under test relies on, but at least jest is able to run the tests where I can test overall functionality of my react component.

[jonnytest1]

yeah the "fix" is definitely hacky , but i dont think thers a good way to do it - cleanest would probably be to fork the project and deploy it with the fix

[jonnytest1]

import { readFileSync, writeFileSync } from 'fs';
import { join } from 'path';

to get the methods - and well the fix implementation would still need some testing to add the property in exports

[Dinika]

@jonnytest1 Thanks for the comment. I did try the suggested solution but I still get the error Cannot find module 'deepdash-es/standalone' from path/to/component/that/uses/deepdash-es;

Here's my jest config:

// File - jest.config.js
const customJestConfig = {
    ... // Other config
      setupFiles: ['./global.mock.js'], // The file inside which I've added the suggested lines
      moduleNameMapper: {
            '^@/(.*)$': '<rootDir>/src/$1',
      },
}
module.exports = createJestConfig(customJestConfig);

And here's the setup file called global.mock.js

import { readFileSync, writeFileSync } from 'fs';
import { join } from 'path';

const packageJsonPath = join(__dirname, 'node_modules/deepdash-es/package.json');
const packageJson = JSON.parse(readFileSync(packageJsonPath, { encoding: 'utf8' }));

// fix package.json
writeFileSync(packageJsonPath, JSON.stringify(packageJson, undefined, '  '));

[jonnytest1]

the comment where it says "fix package.json" still needs an implementation i havent looked at it in details but i think it should be soemthing like

for(let export in packageJson.exports){
   if(!packageJson.exports[export]{
      packageJson.exports[export].require=export+".js
   }
}

or something similar , but the current package.json implementation over at https://github.com/YuriGor/deepdash/blob/master/package.json already seems to be correct , so maybe try to update to the latest version first maybe thers already a release for it