Remove-hardcoded-en-US-locale-issue-#1383

[audiojames]

Hard coding the locale here causes presumably unintended incorrect timezone formatting for users outside of the US. Issue described in #1383, I propose removing the en-US in favour of the browser's default, or what is specified elsewhere.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (06f88f4) to head (6a4bc6a).
⚠️ Report is 271 commits behind head on dev.

Additional details and impacted files

@@            Coverage Diff            @@
##               dev     #1499   +/-   ##
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  Coverage   100.00%   100.00%           
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  Files          176       176           
  Lines         1965      1965           
  Branches       497       497           
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  Hits          1965      1965           

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[iamkun]

I'm not sure if this is the correct way to fix this.

The reason why we set Intl to en-US is to calculate the correct timezone offset. And if we remove it, the timezone result is wrong.

[audiojames]

Undefined, or an empty array will use the browsers default - which makes more sense for people not in the US. Which time zone result are you referring to that is wrong?

[iamkun]

You can run npm test to see the faild test case in this PR.

[Akryum]

A new DateTimeFormat should probably created just for format()?

[kaangokdemir]

That solution solved my issue, thanks @audiojames! I'm not sure if a change on L:98 is required but until this PR merged, I am going to continue with patch-package

For anyone interests to my patch file:

~/patches/dayjs+1.10.4.patch

diff --git a/node_modules/dayjs/plugin/timezone.js b/node_modules/dayjs/plugin/timezone.js
index 9fee932..193bd43 100644
--- a/node_modules/dayjs/plugin/timezone.js
+++ b/node_modules/dayjs/plugin/timezone.js
@@ -1 +1 @@
-!function(t,e){"object"==typeof exports&&"undefined"!=typeof module?module.exports=e():"function"==typeof define&&define.amd?define(e):t.dayjs_plugin_timezone=e()}(this,function(){"use strict";var t={year:0,month:1,day:2,hour:3,minute:4,second:5},e={};return function(n,i,r){var o,u=r().utcOffset(),a=function(t,n,i){void 0===i&&(i={});var r=new Date(t);return function(t,n){void 0===n&&(n={});var i=n.timeZoneName||"short",r=t+"|"+i,o=e[r];return o||(o=new Intl.DateTimeFormat("en-US",{hour12:!1,timeZone:t,year:"numeric",month:"2-digit",day:"2-digit",hour:"2-digit",minute:"2-digit",second:"2-digit",timeZoneName:i}),e[r]=o),o}(n,i).formatToParts(r)},f=function(e,n){for(var i=a(e,n),o=[],u=0;u<i.length;u+=1){var f=i[u],s=f.type,m=f.value,c=t[s];c>=0&&(o[c]=parseInt(m,10))}var d=o[3],v=24===d?0:d,h=o[0]+"-"+o[1]+"-"+o[2]+" "+v+":"+o[4]+":"+o[5]+":000",l=+e;return(r.utc(h).valueOf()-(l-=l%1e3))/6e4},s=i.prototype;s.tz=function(t,e){void 0===t&&(t=o);var n=this.utcOffset(),i=this.toDate().toLocaleString("en-US",{timeZone:t}),a=Math.round((this.toDate()-new Date(i))/1e3/60),f=r(i).$set("millisecond",this.$ms).utcOffset(u-a,!0);if(e){var s=f.utcOffset();f=f.add(n-s,"minute")}return f.$x.$timezone=t,f},s.offsetName=function(t){var e=this.$x.$timezone||r.tz.guess(),n=a(this.valueOf(),e,{timeZoneName:t}).find(function(t){return"timezonename"===t.type.toLowerCase()});return n&&n.value};var m=s.startOf;s.startOf=function(t,e){if(!this.$x||!this.$x.$timezone)return m.call(this,t,e);var n=r(this.format("YYYY-MM-DD HH:mm:ss:SSS"));return m.call(n,t,e).tz(this.$x.$timezone,!0)},r.tz=function(t,e,n){var i=n&&e,u=n||e||o,a=f(+r(),u);if("string"!=typeof t)return r(t).tz(u);var s=function(t,e,n){var i=t-60*e*1e3,r=f(i,n);if(e===r)return[i,e];var o=f(i-=60*(r-e)*1e3,n);return r===o?[i,r]:[t-60*Math.min(r,o)*1e3,Math.max(r,o)]}(r.utc(t,i).valueOf(),a,u),m=s[0],c=s[1],d=r(m).utcOffset(c);return d.$x.$timezone=u,d},r.tz.guess=function(){return Intl.DateTimeFormat().resolvedOptions().timeZone},r.tz.setDefault=function(t){o=t}}});
+!function(t,e){"object"==typeof exports&&"undefined"!=typeof module?module.exports=e():"function"==typeof define&&define.amd?define(e):t.dayjs_plugin_timezone=e()}(this,function(){"use strict";var t={year:0,month:1,day:2,hour:3,minute:4,second:5},e={};return function(n,i,r){var o,u=r().utcOffset(),a=function(t,n,i){void 0===i&&(i={});var r=new Date(t);return function(t,n){void 0===n&&(n={});var i=n.timeZoneName||"short",r=t+"|"+i,o=e[r];return o||(o=new Intl.DateTimeFormat(undefined,{hour12:!1,timeZone:t,year:"numeric",month:"2-digit",day:"2-digit",hour:"2-digit",minute:"2-digit",second:"2-digit",timeZoneName:i}),e[r]=o),o}(n,i).formatToParts(r)},f=function(e,n){for(var i=a(e,n),o=[],u=0;u<i.length;u+=1){var f=i[u],s=f.type,m=f.value,c=t[s];c>=0&&(o[c]=parseInt(m,10))}var d=o[3],v=24===d?0:d,h=o[0]+"-"+o[1]+"-"+o[2]+" "+v+":"+o[4]+":"+o[5]+":000",l=+e;return(r.utc(h).valueOf()-(l-=l%1e3))/6e4},s=i.prototype;s.tz=function(t,e){void 0===t&&(t=o);var n=this.utcOffset(),i=this.toDate().toLocaleString("en-US",{timeZone:t}),a=Math.round((this.toDate()-new Date(i))/1e3/60),f=r(i).$set("millisecond",this.$ms).utcOffset(u-a,!0);if(e){var s=f.utcOffset();f=f.add(n-s,"minute")}return f.$x.$timezone=t,f},s.offsetName=function(t){var e=this.$x.$timezone||r.tz.guess(),n=a(this.valueOf(),e,{timeZoneName:t}).find(function(t){return"timezonename"===t.type.toLowerCase()});return n&&n.value};var m=s.startOf;s.startOf=function(t,e){if(!this.$x||!this.$x.$timezone)return m.call(this,t,e);var n=r(this.format("YYYY-MM-DD HH:mm:ss:SSS"));return m.call(n,t,e).tz(this.$x.$timezone,!0)},r.tz=function(t,e,n){var i=n&&e,u=n||e||o,a=f(+r(),u);if("string"!=typeof t)return r(t).tz(u);var s=function(t,e,n){var i=t-60*e*1e3,r=f(i,n);if(e===r)return[i,e];var o=f(i-=60*(r-e)*1e3,n);return r===o?[i,r]:[t-60*Math.min(r,o)*1e3,Math.max(r,o)]}(r.utc(t,i).valueOf(),a,u),m=s[0],c=s[1],d=r(m).utcOffset(c);return d.$x.$timezone=u,d},r.tz.guess=function(){return Intl.DateTimeFormat().resolvedOptions().timeZone},r.tz.setDefault=function(t){o=t}}});