Additional unit tests and coverage.

[shimkiv]

Closes #645 Closes #650

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• Codecov project can be found here: https://app.codecov.io/gh/o1-labs/zkapp-cli
• From now on we will run other CI jobs on the success of Unit tests only.
  • This will allow us to fail faster and save resources.
• CI dependencies were refactored.
  • Publishing on NPM will now be triggered on the success of Unit and Smoke tests.
  • CI dependencies: Common unit tests ← Examples unit tests ← Smoke E2E tests ← Publish to NPM.
  • Turned out these CI changes have to be merged into the default branch first to make it work properly. That is why, for example, we don't seeSmoke E2E tests workflow being triggered for this PR, not publishing on NPM. But they will work once merged to default branch.
• From now on Jest will fail the Unit tests execution in case if resulting coverage will be less than configured threshold.
  • This will force us to write additional Unit tests on main codebase changes.
• Please note that If something is configured to be ignored for coverage (using /* istanbul ignore next */) it either covered by E2E tests and needs to be covered by unit tests as part of tasks linked to this PR or it is tough to mock.

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• Includes changes for the lightnet local posts availability checking (we want to check both 127.0.0.1 and localhost).

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• Some issues faced during the tests implementation:

  • Jest, Mocha, native Node.js test runner, all have issues when it comes to ES modules and async code mocking.
  • Jest still doesn't have production-ready support for ESM. This was causing several major pitfalls.
  • Inability to partially mock methods from the same module that some particular method is being currently tested. This was causing a lot of pain because, to test certain methods, you now had to prepare and mock (where possible) the env. in such a way that will "drive" the method under the test execution in the way you need it for testing purposes.
  • Inability to properly check methods’ execution results in cases when some mocked parts were executed 2-3 levels deep in Promises (Promise -> calls Promise -> calls method). I was not able to spy on the results of such methods nor parameters such methods were called with. That is why checks for some tests look ugly.

• Some parts of different tests could be optimized much better, but it would take another eternity to do so. I decided that for now we will only want to have unit tests in place working for us and take care of optimization later.

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• Do we want the Unit tests to be configured as mandatory pre-commit hook (alongside with the currently configured linter)?

[codecov[bot]]

Welcome to Codecov :tada:

Once you merge this PR into your default branch, you're all set! Codecov will compare coverage reports and display results in all future pull requests.

Thanks for integrating Codecov - We've got you covered :open_umbrella:

[shimkiv]

Note for assignee: address TODO in CI config: https://github.com/o1-labs/zkapp-cli/pull/662.

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UPD: Done.

[shimkiv]

https://app.codecov.io/gh/o1-labs/zkapp-cli/tree/feat%2Funit-tests

[shimkiv]

Smoke testing run against this branch: https://github.com/o1-labs/zkapp-cli/actions/runs/9970821097 Please refer to PR's description for the information about why it is not picked up.