production mode with es2015 breaks angular/common/http in angular-cli 6 beta 5 #9989
Description
Versions
<!--
Angular CLI: 6.0.0-beta.5
Node: 9.7.1
OS: darwin x64
Angular: 6.0.0-beta.7
... animations, common, compiler, compiler-cli, core, forms
... http, language-service, platform-browser
... platform-browser-dynamic, router
@angular/cdk: 6.0.0-beta.4
@angular/cli: 6.0.0-beta.5
@angular/flex-layout: 5.0.0-beta.13
@angular/material: 6.0.0-beta.4
@angular-devkit/build-optimizer: 0.4.5
@angular-devkit/core: 0.4.5
@angular-devkit/schematics: 0.4.5
@ngtools/json-schema: 1.2.0
@ngtools/webpack: 6.0.0-beta.5
@schematics/angular: 0.4.5
@schematics/package-update: 0.4.5
typescript: 2.6.2
webpack: 4.0.1
Repro steps
- Change
tsconfig.jsontoes2015 - Use angular-cli production mode (
ng serve ---target=production --environment=prod) - Use @angular/common/http
- Make HTTP request
Observed behavior
TypeError: Assignment to constant variable.
In this line:
o = ("responseURL"in (n = n) && n.responseURL ? n.responseURL : /^X-Request-URL:/m.test(n.getAllResponseHeaders()) ? n.getResponseHeader("X-Request-URL") : null) || t.url;
The problem is (n = n). Because n is defined as const n = this.xhrFactory.build();
Here are the corresponding lines in the angular source code:
o = ... = url = ...: https://github.com/angular/angular/blob/c8a1a14b87e5907458e8e87021e47f9796cb3257/packages/common/http/src/xhr.ts#L147
n = n: https://github.com/angular/angular/blob/c8a1a14b87e5907458e8e87021e47f9796cb3257/packages/common/http/src/xhr.ts#L25
Desired behavior
No error ;-)
Mention any other details that might be useful (optional)
It looks like the error comes from function inlining.
But I'm not sure if this problem is part of angular itself, or the TypeScript Compiler, or Uglify, or angular-cli because of bad default production settings.