feat: Add --indent option to CLI tool

[danielbayley]

Add a --indent option, to be used with --json to output 2 space indentation.

See also #479 and #523.

[eemeli]

I have two concerns with this change:

1. Could you clarify what's the use case of pretty-printed JSON output? For single-shot manual use, wouldn't the same be served by piping the output to a separate JSON prettifier like jq?

2. Naming the option as "pretty" and only affecting the JSON output seems rather misleading. Either the option needs to make sense independently of --json, or it needs to be named more specifically.

[danielbayley]

1. Could you clarify what's the use case of pretty-printed JSON output? For single-shot manual use, wouldn't the same be served by piping the output to a separate JSON prettifier like jq?

Non single-shot manual use… Like in package.json (package.yaml) scripts.

Moreover, I want to do a PR for pnpm to replace it’s dependency on js-yaml (which hasn’t had an update for 3+ years) with this library, which is superior, and handles comments much better!

Forcing this to be inflexible, and add an extra dependency just to make JSON output readable, adding friction to adoption for the sake of basically a single line of code—in fact just a single parameter to an existing builtin function—seems silly…

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2. Naming the option as "pretty" and only affecting the JSON output seems rather misleading. Either the option needs to make sense independently of --json, or it needs to be named more specifically.

I had a similar thought, but there is no such thing as --pretty YAML, it already has to be indented…

I think the ideal API would be an optional parameter, maybe to --json, e.g --json 2 or something, but that isn’t really a feature of util.parseArgs. How about --indent? What other name do you think would be better? @eemeli

This is the yaml.js API, for reference.

[eemeli]

1. Could you clarify what's the use case of pretty-printed JSON output? For single-shot manual use, wouldn't the same be served by piping the output to a separate JSON prettifier like jq?

Non single-shot manual use… Like in package.json (package.yaml) scripts.

Eh, not sure that it really makes sense to prettify output that's meant for machine consumption, as it risks creating JSON files that will be presumed to be the source of truth, rather than intermediate build assets. But I'll grant you that there's probably a valid use case somewhere here.

2. Naming the option as "pretty" and only affecting the JSON output seems rather misleading. Either the option needs to make sense independently of --json, or it needs to be named more specifically.

I had a similar thought, but there is no such thing as --pretty YAML, it already has to be indented…

I think the ideal API would be an optional parameter, maybe to --json, e.g --json 2 or something, but that isn’t really a feature of util.parseArgs. How about --indent? What other name do you think would be better?

--indent works, esp. as it's already an option for YAML formatting. Switch this PR to that and make it apply to YAML output as well?

[danielbayley]

it risks creating JSON files that will be presumed to be the source of truth

Well the YAML files are the source… But a lot of tools only work from JSON. Harder to debug if it has to be minified also…

--indent works, esp. as it's already an option for YAML formatting. Switch this PR to that and make it apply to YAML output as well?

Good idea, will look into it…

[eemeli]

Overall the API looks good, see inline for implementation changes.

[eemeli]

Thank you, this looks good! Sorry for the delay in getting to this. There was a missing newline from the test source, which I added to get the test to pass.

[danielbayley]

Thank you, this looks good! Sorry for the delay in getting to this. There was a missing newline from the test source, which I added to get the test to pass.

No worries, life gets in the way… I know!