Jest: Running with --testResultsProcessor raises error

[segrey]

Do you want to request a feature or report a bug?
Bug

What is the current behavior?

Running jest tests with --testResultsProcessor raises an error. It can be reproduced with https://github.com/facebook/jest/tree/master/examples/getting_started

// add processor.js
module.exports = function() {};

./node_modules/jest/bin/jest.js --testResultsProcessor=./processor.js
 PASS  ./sum.test.js
  ✓ adds 1 + 2 to equal 3 (4ms)

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        0.617s, estimated 1s
Ran all test suites.
Error: AggregatedResult must be present after test run is complete
    at /home/segrey/samples/jests/jest/examples/getting_started/node_modules/jest/node_modules/jest-cli/build/cli/index.js:86:15
    at Generator.next (<anonymous>)
    at step (/home/segrey/samples/jests/jest/examples/getting_started/node_modules/jest/node_modules/jest-cli/build/cli/index.js:46:2233)
    at /home/segrey/samples/jests/jest/examples/getting_started/node_modules/jest/node_modules/jest-cli/build/cli/index.js:46:2393
    at <anonymous>

Reproduced with jest 21.0.1. It works OK with jest 20.0.4.

node 8.4.0
yarn 0.27.5
jest 21.0.1

[cpojer]

This is a breaking change. You need to return the result from the processor (might require a docs update, mind changing a PR?)

[segrey]

Thanks, seems module.exports = function(result) { return result; }; works OK. BTW, what's the idea behind modifying the result?

[pascalduez]

Hi,

this kind of breaking changes should be part of the Changelog IMO.
Actually, I find the jest@21 Changelog rather unhelpfull, it's a collection of commits or issues/PRs.

Yes I know, writting a proper human friendly Changelog is a lot of work, no critic intented.