Add tests for "swift: Fix --operationIdsPath option" #1431

[manicmaniac]

I took over the rest tasks (adding tests) of #1431.
Could you make sure that it is enough?

• Rebased onto the current HEAD of master branch
• Modified existing tests and updated snapshots
• Confirmed the tests passed in my local env
  • However it looks flaky so I ran tests with node node_modules/.bin/jest -t generate -i --no-cache to exclude unchanged.

TODO:

• Update CHANGELOG.md* with your change (include reference to issue & this PR)
• Make sure all of the significant new logic is covered by tests
• Rebase your changes on master so that they can be merged easily
• Make sure all tests and linter rules pass

*Make sure changelog entries note which project(s) has been affected. See older entries for examples on what this looks like.

[designatednerd]

Looks reasonable to me but would love a look from @JakeDawkins, who actually knows how javascript works, unlike me 😆

[manicmaniac]

@designatednerd Sorry for the additional commit after receiving LGTM.

I just found that the current generated code for Swift doesn't have a newline between query and fragment.
Because of missing newlines, the generated operation ID and sent query's sha256 hash always differs.
After this change, operation ID and sha256 will be same so we can treat Persisted Query more easily.

[manicmaniac]

The current implementation outputs the following query document as source property of operationIds.json.
sha256 hash calculated from this source is put into the same operationIds.json.

query SomeQuery {
    ...SomeFragment
}
fragment SomeFragment {
    id
}

However, Apollo iOS sends the following query document (missing newlines).
sha256 hash is calculated from this source at runtime so there's difference between 2 hashes.

query SomeQuery {
    ...SomeFragment
}fragment SomeFragment {
    id
}

This commit fixes this problem with appending missing newlines.

[manicmaniac]

@JakeDawkins Could you take a look at this one when you have time?

[JakeDawkins]

@manicmaniac this looks good to me! Thanks for your patience here! :)