Add ability to mock out process.stdout calls #118
Description
Currently issueCommand always outputs to stdout here: https://github.com/actions/toolkit/blob/master/packages/core/src/command.ts#L25. This is great but when writing tests for actions it quickly fills up the logs:
> @ test /Users/njero/Code/Examples/example-github-action-typescript
> jest
PASS .github/actions/debug-action/__tests__/debug.test.ts
debug action debug messages
✓ outputs a debug message (5ms)
##[debug]👋 Hello! You are an amazing person! 🙌
##[debug]👋 Hello! You are an amazing person! 🙌
Test Suites: 1 passed, 1 total
Tests: 1 passed, 1 total
Snapshots: 0 total
Time: 1.423s
Ran all test suites.
If the output was wrapped in a call on the Command object itself then it could be mocked in the jest setup. Additionally this might pave the way for alternate logging outputs down the road.