fix: ensure an empty array request parameter is stringified and passed through

[jgravois]

i'm working on a web component that updates user tags and noticed this afternoon that we currently don't pass a value at all when an empty array is provided as a request parameter.

request(updateUserUrl, {
  params: { tags: [] }, 
  authentication
});

ArcGIS Online's (understandable) reaction to this call is to make no edits to the user's current tags, when in actuality I want to remove them all.

AFFECTS PACKAGES:
@esri/arcgis-rest-request

[codecov]

Codecov Report

Merging #474 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff          @@
##           master   #474   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files          94     94           
  Lines        1209   1210    +1     
  Branches      219    220    +1     
=====================================
+ Hits         1209   1210    +1

Impacted Files	Coverage Δ
...es/arcgis-rest-request/src/utils/process-params.ts	100% <100%> (ø)	⬆️

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[jgravois]

huh, it turns out this isn't the right thing to do at all.

i should have been using the optional clearEmptyFields parameter instead.

[jgravois]

wow.

clearEmptyFields only works on string fields. apparently you're supposed to clear a user's current tags like this:

tags: [","]
// or
tags: ","

¯\(ツ)/¯