undocumented breaking change in v3 : ng-packagr doesn't generate a tarball anymore

Type of Issue

[ ] Bug Report
[ ] Feature Request
[x] documentation

(A feature request could be hadded to angular/devkit).

Description

When building a library, ng-packagr doesn’t generate any tarball anymore.

The expected behaviour was added by @filipesilva #715 See https://github.com/dherges/ng-packagr/commit/94bc915#diff-2e14a1a49f5dcec2e1af74d135633651R38

These regression was introduced by @alan-agius4 #738. See https://github.com/dherges/ng-packagr/commit/4e6c4f4bb21869c69f084560af3fa75531e4d07f#diff-2e14a1a49f5dcec2e1af74d135633651L133

But the breaking change wasn’t mentionned in https://github.com/dherges/ng-packagr/blob/master/CHANGELOG.md#breaking-changes.

How To Reproduce

The associated test (https://github.com/dherges/ng-packagr/commit/94bc91513767e965778df299862b7d28428a2491#diff-7590c1f6c6a53411a7569652cab76e3cR28) was removed (https://github.com/dherges/ng-packagr/commit/4e6c4f4bb21869c69f084560af3fa75531e4d07f#diff-7590c1f6c6a53411a7569652cab76e3cL27).

Expected Behaviour

As we could see in #738 discussion, the drop of the tarball generation seems to make sence (https://github.com/dherges/ng-packagr/pull/738#issuecomment-379457152).

So, we’ll need to :

1. document this breaking change, especially how the tarball should be generated (with npm pack)
2. make the associated evolution in @angular-devkit/build-ng-packagr

Version Information

ng-packagr:            3.0.0-rc.2
@angular/compiler:     5.2.10
@angular/compiler-cli: 5.2.10
rollup:                0.57.1
tsickle:               0.26.0
typescript:            2.6.2

[alan-agius4]

Just some takeouts though why it’s not part of the current build.

At the moment a lot of users have postbuild scripts in order to do some transformation in the bundle, example bundle scss files, add some other files. Generating a tarball from ng-packagr after the build steps would be invalid. (This is actually one of the problems with the initial approach https://github.com/dherges/ng-packagr/pull/715#issuecomment-378901242)

[noelmace]

@alan-agius4 no problem, I saw the discussion and it make sense. For now I will just add this as a postbuild in my project, and later I’ll look at devkit, to see if we could add this to the ng-packagr build architect.