fix :: in call expr comment causing crash

[thecodrr]

Fixes #7748

Prettier crashed when :: appeared in a call expression. This PR is supposed to fix that. The error is due to Prettier (wrongly) assuming that the comment is a Flow annotation. I have added a check against empty flow annotations which fixes it.

However, I can't seem to get the tests to pass. I have manually tested with both the CLI & the API (with all parsers) and it works. The playground works too but when I run the test suite with x(/* :: */[]); input, prettier automatically erases the comment. Don't know why. This happens even without my changes. @thorn0 would appreciate any help 😄

• I’ve added tests to confirm my change works.
• (If changing the API or CLI) I’ve documented the changes I’ve made (in the docs/ directory)
• (If the change is user-facing) I’ve added my changes to changelog_unreleased/*/pr-XXXX.md file following changelog_unreleased/TEMPLATE.md.
• I’ve read the contributing guidelines.

✨Try the playground for this PR✨

[thorn0]

Unfortunately, can't help you with this. I don't have much time now, and Flow comment types are a mess.

[thorn0]

superseded by #13687