Add export package-information command

[Papipo]

Closes #4240

• Adds Serialize trait to PackageConfig and all types it depends on.
• Adds serde options to skip flags that have default values.
• Adds gleam export package-information --out [out] command
• Fixes gleam export package-interface format for gleam_version_constraint, which was being exported like: "gleam-version-constraint":"1.8.0 <= v" because it relied on pubgrub. Now it uses hexpm format and emits >= 1.8.0.

[lpil]

Wonderful, thank you!

Let's make it always render all the fields, even if they are the defaults. This will make it easier to understand what all the fields are.

It would also be good to have some round-trip tests, to ensure that a config file serialised and then deserialise doesn't have a bug that results in data-loss.

[Papipo]

@lpil I think all comments have been handled.

Let me know if I should squash some commits or something.

[lpil]

Thank you, but not all the comments have been resolved. Please remove all the serialisation skipping, the trait use, and merge the duplicate serde attribute.

[Papipo]

Thank you, but not all the comments have been resolved. Please remove all the serialisation skipping, the trait use, and merge the duplicate serde attribute.

Dammit, I think I had some rebasing issue 😮‍💨

[lpil]

Ah I hate it when that happens!

[Papipo]

@lpil The duplicate serde attribute was removed rather than merged due to the removal of all skips.

[lpil]

Oh! The test failed due to ordering, but you've got preserve_order as a serde feature. Is that not enough to make the order deterministic or is there more to do there?

[Papipo]

Oh! The test failed due to ordering, but you've got preserve_order as a serde feature. Is that not enough to make the order deterministic or is there more to do there?

I thought it was enough as you can expect, sigh. Gonna investigate as it!

[Papipo]

Should be fixed now, it was my fault (obsolete snapshot).

[lpil]

Tests are failing!

[lpil]

Thank you! Could you update the changelog please

[Papipo]

Thank you! Could you update the changelog please

Done and rebased due to conflicts.

[lpil]

Thank you

[lpil]

Oh! I've just noticed that the top level {"gleam.toml": is missing!

[Papipo]

Oh! I've just noticed that the top level {"gleam.toml": is missing!

Oh, nice catch. That was definitely lost when I trashed the first iteration. Working on it 🚀

[Papipo]

In fact there is no test for this nesting thing, as the snapshots are for the PackageConfig serialisation and the nesting is happening at the export command level. Should I add a snapshop test for this?

[lpil]

We want the tests to test this output, not just a subset of that output 🙏 Move the nesting out of the command please and have the test do that new serialisation thingy

[Papipo]

We want the tests to test this output, not just a subset of that output 🙏 Move the nesting out of the command please and have the test do that new serialisation thingy

I introduced the PackageInformation struct to deal with these matters, let me know if it looks good now.

[lpil]

Thank you!!