Adding JSON output

[erica]

Provide a lightweight JSON output to support scripting.

cc @Impedimenta, @taquitos

[erica]

now provides three modes of output:

• current time
• adjusted remote time
• adjusted local time

My first pass at this produces the following output:

% now bath uk --remote 4p -j
{
  "place" : "Local",
  "zone_name" : "Mountain Time",
  "provider" : "https:\/\/github.com\/erica\/now",
  "time_zone" : "MDT",
  "time" : "2020-06-02T15:00:00Z",
  "version" : "1.0.0"
}
% now bath uk --local 9a -j
{
  "place" : "Bath",
  "zone_name" : "United Kingdom Time",
  "provider" : "https:\/\/github.com\/erica\/now",
  "time_zone" : "GMT+1",
  "time" : "2020-06-02T15:00:00Z",
  "version" : "1.0.0"
}
% now bath uk -j
{
  "place" : "Bath",
  "zone_name" : "United Kingdom Time",
  "provider" : "https:\/\/github.com\/erica\/now",
  "time_zone" : "GMT+1",
  "time" : "2020-06-02T16:20:41Z",
  "version" : "1.0.0"
}

Update: Added json branch to test.

I need concrete feedback as to what would be appropriate and useful output

[rjstelling]

This actually looks pretty good.

I'm not sure of the need for a provider key, especially if it's always going to be "https:\/\/github.com\/erica\/now"?

I do have a feature request, adding a --pretty @Flag. So we can get unformatted JSON out.

@Flag(default: true, inversion: .prefixedNo)
var pretty: Bool

This will turn on prettification by default and passing --no-pretty will turn it off, that seems like the best default to me.

[erica]

I'm hesitant to add more exposed features to a utility I want to keep simple. Can you argue against pretty JSON for me? As far as I know, decoders can ignore the pretty printing.

I want to introduce only one format (non-pretty or pretty) and a single option (--json / -j) to keep that exposed surface area small.

I think there's value to having a version in case the output changes but agree the provider is marginally pointless.

Update: Pushed version to json removing provider.

[rjstelling]

No, you are correct. I don't have a good argument against pretty JSON being the only option.

I agree with the version, I'm assuming it's going to follow Semantic Versioning?

[rjstelling]

I just posted my Semantic Versioning code to a gist, it might be useful: https://richardstelling.com/Swift-Gists/#semantic-versioning

[erica]

@rjstelling How about a single digit: version 1, 2, 3...? I don't anticipate changing the JSON output but I'd like to have a version there just in case.

[rjstelling]

Personally I prefer to have the option of Semantic Versioning, but 1, 2 etc are still valid semantic versions. So, everyone is a winner.

[erica]

I'm going to go with that, then, with the understanding that I expect the JSON to not change much (if at all over time). Closing this issue and pushing the version with JSON support.