Liquid filter: where - compatibility with Jekyll

[Nowaker]

where filter in Liquidjs is not compatible with Jekyll syntax. This is a reimplemented version of where that works the same as Jekyll:

  engine.registerFilter('where', function (input, property, value) {
    const array = (function (val) {
      if (_.isArray(val)) {
        return val
      }

      if (_.isString(val) && val.length > 0) {
        return [val]
      }

      if (_.isObject(val)) {
        return Object.keys(val).map(function (key) {
          return val[key]
        })
      }

      return []
    })(input)

    let valueString = value
    if (_.isBoolean(value)) {
      valueString = value.toString()
    }

    return array.filter((obj) => {
      let prop = obj[property]
      if (prop == value) {
        return true
      }

      if (_.isBoolean(prop) && prop.toString() == valueString) {
        return true
      }

      return false
    })
  })

How would we go about this? Maybe rename jekyllInclude option into jekyllMode, and enable the include feature, and this filter when enabled?

Or implement jekyllWhere that enables a different implementation, plus jekyllMode that when enabled, enables all Jekyll compatibilities?

[harttle]

@Nowaker , thank you for digging into this!

This is a reimplemented version of where that works the same as Jekyll

I'm OK to merge this into LiquidJS, but we need test cases to highlight the difference. Or, a diff patch to highlight the change for

liquidjs/src/builtin/filters/array.ts

Lines 40 to 45 in 1e69d86

	export function where<T extends object> (this: FilterImpl, arr: T[], property: string, expected?: any): T[] {
	return toArray(arr).filter(obj => {
	const value = this.context.getFromScope(obj, String(property).split('.'))
	return expected === undefined ? isTruthy(value, this.context) : value === expected
	})
	}

I guess maybe we need a toJekyllArray?

Or implement jekyllWhere that enables a different implementation, plus jekyllMode that when enabled, enables all Jekyll compatibilities?

I prefer the latter, it's backward-compatible.

[Nowaker]

but we need test cases to highlight the difference

This is totally understood. After I've finished my Jekyll-in-Gatsby project, including business deliverables, I'll work on putting that code into Liquidjs and submitting PRs.