Migrating from 6.1 to 7.2 does not remove/move reflect metadata polyfill

[Astrophizz]

🐞 Bug report

Command (mark with an x)

- [ ] new
- [ ] build
- [ ] serve
- [ ] test
- [ ] e2e
- [ ] generate
- [ ] add
- [x] update
- [ ] lint
- [ ] xi18n
- [ ] run
- [ ] config
- [ ] help
- [ ] version
- [ ] doc

Is this a regression?

No.

Description

According to the blog post about Angular 7, updating to Angular 7 should remove the reflect metadata polyfill. The work in #12314, #12611, and #12625 suggests it might also get moved the the dev environment, though discussions around the code seem to disagree. No changes are made to polyfill.ts when updating.

🔬 Minimal Reproduction

Run ng update --all --force on an Angular 6 application (this works around other outstanding issues with ng update).

🌍 Your Environment

     _                      _                 ____ _     ___
    / \   _ __   __ _ _   _| | __ _ _ __     / ___| |   |_ _|
   / △ \ | '_ \ / _` | | | | |/ _` | '__|   | |   | |    | |
  / ___ \| | | | (_| | |_| | | (_| | |      | |___| |___ | |
 /_/   \_\_| |_|\__, |\__,_|_|\__,_|_|       \____|_____|___|
                |___/
    

Angular CLI: 6.2.5
Node: 10.15.0
OS: win32 x64
Angular: 6.1.10
... animations, common, compiler, compiler-cli, core, forms
... http, language-service, platform-browser
... platform-browser-dynamic, router

Package                           Version
-----------------------------------------------------------
@angular-devkit/architect         0.6.8
@angular-devkit/build-angular     0.6.8
@angular-devkit/build-optimizer   0.6.8
@angular-devkit/core              0.6.8
@angular-devkit/schematics        0.6.8
@angular/cli                      6.2.5
@ngtools/webpack                  6.0.8
@schematics/angular               0.8.5
@schematics/update                0.8.5
rxjs                              6.3.3
typescript                        2.9.2
webpack                           4.8.3

Anything else relevant?

Not that I can think of. It might be nice for the Angular Update Guide to explain how to manually migrate the polyfill if the automated migration does not do anything.

[alan-agius4]

Hi, I tried to replicate this and the import 'core-js/es7/reflect'; was removed.

Can you setup a minimal repro please?

This might be related to your directory structure so its really important to get an accurate repro to diagnose this.

Thanks

[Astrophizz]

In attempting to create a minimal repro by amputating my application until it resembled a fresh Angular project and the migration still failing to remove the polyfill, I think I've narrowed in on the difference between a successful migration and one that doesn't remove the reflect polyfill. The key difference was whether I ran ng update --all without a pre-existing .\node_modules (success) or running npm i to populate .\node_modules before ng update --all (failure). Here's a repo where you can try it yourself: https://github.com/Astrophizz/angular-6-to-7-reflect-polyfill

On a side note, I do find it odd that the migration removes the polyfill import but not the comment describing it.

[alan-agius4]

@Astrophizz, the problem seems to be caused because of an older version of @angular-devkit/build-angular. Kindly update this to at least 0.8.0.

Also you don't need to depending on these packages directly as this might cause undefined behaviour.

    "@angular-devkit/core": "^0.6.5",
    "@angular-devkit/schematics": "^0.6.5",

in https://github.com/Astrophizz/angular-6-to-7-reflect-polyfill/blob/11352852849fdae77d304d6a5d8e9eba7937d3c3/package.json#L44-L45

[Astrophizz]

Thanks for finding that and for the guidance!

---

The rest of this comment may be more useful to anyone who stumbles across this in the future.

Those references to @angular-devkit/* were added when I updated @ngrx/schematics from version 5 to 6. It seems that @angular-devkit/core and @angular-devkit/schematics were peer dependencies for @ngrx/schematics back then (in June 2018) and somehow got added to the devDependencies. The commits were squashed and I don't recall if I added them to devDependencies to address a peer dependency warning. Fortunately those peer dependencies have since been removed, so I expect I'll be able to make the changes you suggested without breaking @ngrx/schematics 🙂