Unexpected reserved word 'arguments' when running translations --localize

[thduttonuk]

🐞 bug report

Is this a regression?

Yes, it worked in Angular 8

Description

Running ng build --prod --localize causes the error Unexpected reserved word 'arguments' but running ng build --prod builds fine. I have tracked this down to superagent that is referenced by Auth0. What I don't understand is why only --localize causes the build error. We are building and deploying the code using --prod builds, we are blocked on the --localize builds.

🔬 Minimal Reproduction

I have created a repo for reproduction
https://github.com/thduttonuk/angular9-issue1

Run
ng build --prod this builds fine
ng build --prod --localize causes Unexpected reserved word 'arguments'

🔥 Exception or Error

Localized bundle generation failed: angular9-issue1\main-es2015.acfa3bd7294e9b8980d0.js: Unexpected reserved word 'arguments' (1:481223)
An error occurred inlining file "main-es2015.acfa3bd7294e9b8980d0.js"

🌍 Your Environment

Angular Version:

Angular CLI: 9.1.1
Node: 12.16.1
OS: win32 x64

Angular: 9.1.1
... animations, cli, common, compiler, compiler-cli, core, forms
... language-service, localize, platform-browser
... platform-browser-dynamic, router
Ivy Workspace: Yes

Package                           Version
-----------------------------------------------------------
@angular-devkit/architect         0.901.1
@angular-devkit/build-angular     0.901.1
@angular-devkit/build-optimizer   0.901.1
@angular-devkit/build-webpack     0.901.1
@angular-devkit/core              9.1.1
@angular-devkit/schematics        9.1.1
@ngtools/webpack                  9.1.1
@schematics/angular               9.1.1
@schematics/update                0.901.1
rxjs                              6.5.5
typescript                        3.8.3
webpack                           4.42.0

Anything else relevant?
No

[thduttonuk]

I've tested this more and setting "optimization": false, in the angular.json config stops the error and it builds. Obviously we don't want to do this as a work around due to the size of the bundles.

[Mark-SofTools]

This is causing a real issue with new clients in Japan not being able to see correct versions.

Could someone give an estimate on time to fix please?

[petebacondarwin]

It seems that it is this function in auth0-js that is causing the error:

	["use", "on", "once", "set", "query", "type", "accept", "auth", "withCredentials", "sortQuery", "retry", "ok", "redirects",
	 "timeout", "buffer", "serialize", "parse", "ca", "key", "pfx", "cert"].forEach(function(fn) {
	  /** Default setting for all requests from this agent */
	  Agent.prototype[fn] = function(/*varargs*/) {
	    this._defaults.push({fn:fn, arguments:arguments});
	    return this;
	  };
	});

[petebacondarwin]

I don't know why this is causing Babel to complain about the arguments variable, since it looks valid to me...

[thduttonuk]

@petebacondarwin The code in auth0 compiles fine when not using --localize its only an issue when adding this flag. So we can't generate the translated builds.