proc-log is designed to be Just an Event Emitter ™️ with some well known event names.
This means it passes along all arguments when emitting to consumers. This is a good approach because there are rarely changes that proc-log needs to make outside of adding new methods. If a producer sends arguments then it is the consumers responsibility to consume them somehow.
Our primary use case is displaying things in a terminal. So all arguments are passed to util.format which can take anything as input. We might be displaying a string, number, plain function or custom class with a [util.inspect.custom] method.
BUT most of the examples I wrote out in npm/statusboard#810 rely on some kind of well-known metadata to be useful. This is why I think proc-log should have some way to indicate "this event contains an argument that is special and belongs to proc-log. It will have data in it that you should look at differently than the rest"
Possible Solutions
Producers
proc-log itself should have some sort of ergonomic API to send this metadata.
meta() function on each method
const { output, log } = require('proc-log')
// Each function gets an additional `meta` function which indicates
// the first parameter is special
output.standard.meta(
{ colors: false, template: './arbitrary' },
'anything', 'else', new You(), { want: new Set() }
)
// could also be the last parameter
output.standard.meta('anything', 'else', new You(), { want: new Set() }, {
colors: false,
template: './arbitrary'
})top level meta() function
const { output, log, meta } = require('proc-log')
// Wrap an object in the meta function which will somehow mark it as special
output.standard(
meta({ colors: false, template: './arbitrary' }),
'anything', 'else', new You(), { want: new Set() }
)
// Can't enforce which location its used in, which seems bad
output.standard('anything', 'else', new You(), { want: new Set() }, meta({
colors: false,
template: './arbitrary'
}))use a symbol to set a key
const { output, log, META } = require('proc-log')
// Still need to figure out which position the argument goes in
output.standard('anything', 'else', new You(), { want: new Set() }, {
[META]: true,
colors: false,
template: './arbitrary'
}))Consumers
Consumers listening with process.on(eventName) should have some ergonomic way to know that an argument is metadata.
level argument is metadata too
const { output, meta } = require('proc-log')
// This would be a breaking change
process.on('output', ({ level, ...metadata }, ...args) =>
if (level === 'standard' && metadata.templates) {
// It is a template
}
})helper to find metadata in args
const { output, meta } = require('proc-log')
process.on('output', (level, ...rawArgs) => {
const [args, metadata] = meta.getMeta(rawArgs)
if (level === 'standard' && metadata.templates) {
// It is a template
}
})
proc-logis designed to be Just an Event Emitter ™️ with some well known event names.This means it passes along all arguments when emitting to consumers. This is a good approach because there are rarely changes that
proc-logneeds to make outside of adding new methods. If a producer sends arguments then it is the consumers responsibility to consume them somehow.Our primary use case is displaying things in a terminal. So all arguments are passed to
util.formatwhich can take anything as input. We might be displaying a string, number, plain function or custom class with a[util.inspect.custom]method.BUT most of the examples I wrote out in npm/statusboard#810 rely on some kind of well-known metadata to be useful. This is why I think
proc-logshould have some way to indicate "this event contains an argument that is special and belongs to proc-log. It will have data in it that you should look at differently than the rest"Possible Solutions
Producers
proc-logitself should have some sort of ergonomic API to send this metadata.meta() function on each method
top level meta() function
use a symbol to set a key
Consumers
Consumers listening with
process.on(eventName)should have some ergonomic way to know that an argument is metadata.level argument is metadata too
helper to find metadata in args