:memo: I submit the same text to GitHub Support.

---
I want to use same scope for npm package and GitHub Package Registry.

For example, `@org` scope exist in npm and GitHub.

- `@org/foo-public` package is public on npm registry
- `@org/bar-private` package is private on GitHub Package Registry

This situation is often the case.
`@org/foo-public` is OSS library and `@org/bar-private` is internal library.

But, I can not use both at same time.

When I used following npmrc config, I could not refer to `@org/foo-public`.
Because `https://npm.pkg.github.com/foo` does not proxy to npm
I can only refer to `@org/bar-private`

```
//npm.pkg.github.com/:_authToken=YYY
registry="https://npm.pkg.github.com/org"
```

## Reproduce Example

`.npmrc`
```
//registry.npmjs.org/:_authToken=XXX # login my npm account
//npm.pkg.github.com/:_authToken=YYY # login my github account

registry=https://npm.pkg.github.com/azu
```

Refs: https://help.github.com/en/github/managing-packages-with-github-packages/configuring-npm-for-use-with-github-packages#installing-packages-from-other-organizations

### Example Pacakge

- npm: https://www.npmjs.com/package/@azu/testtest
  -  is my public package on npm reigstry
- GitHub: https://github.com/azu/npm-github-package-example
   - is my package on GitHub Package reigstry

### Actual

I can not fetch `@azu/testtest` package from npm reigstry.
Because, GitHub Package Registry does not proxy to npm registry about scoped package.

```
$  npm info @azu/testtest
npm ERR! code E404
npm ERR! 404 '@azu/testtest' is not in the npm registry.
npm ERR! 404 You should bug the author to publish it
npm ERR! 404 (or use the name yourself!)
npm ERR! 404
npm ERR! 404 Note that you can also install from a
npm ERR! 404 tarball, folder, http url, or git url.
npm ERR! 404
npm ERR! 404  '@azu/testtest@latest' is not in the npm registry.
npm ERR! 404 You should bug the author to publish it (or use the name yourself!)
npm ERR! 404
npm ERR! 404 Note that you can also install from a
npm ERR! 404 tarball, folder, http url, or git url.

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/azu/.npm/_logs/2020-01-10T13_54_07_224Z-debug.log
```

`@azu` scope work only for GitHub Package Registry

```
$ npm info @azu/npm-github-package-example

@azu/npm-github-package-example@2.3.0 | MIT | deps: none | versions: 9
npm registry to GitHub Package Registry example.
https://github.com/azu/npm-github-package-example

dist
.tarball: https://npm.pkg.github.com/download/@azu/npm-github-package-example/2.3.0/3bdb8322c3344012bcf5ab5819f433fc1e2029ca5a9cf42e8580a2dd0086d9e1
.shasum:

dist-tags:
latest: 2.3.0

published over a year ago by undefined <undefined>
```

### Expected

Both is work.

```
$ npm info @azu/testtest

@azu/testtest@1.0.0 | MIT | deps: none | versions: 2

dist
.tarball: https://registry.npmjs.org/@azu/testtest/-/testtest-1.0.0.tgz
.shasum: a8ed44b4e3ea61011fc257a238aa36306ef316f3
.integrity: sha512-UPyAXnx64pWO14oUGwJlTm1f1VAIMOWMKl5YlXCXETxfJSBxjHi0WR2sKk2JVls1CacLttmv0FwXXwFufNJvIg==
.unpackedSize: 230 B

maintainers:
- azu <azuciao@gmail.com>

dist-tags:
a1: 1.0.1      a: 1.0.0       latest: 1.0.0

published 6 months ago by azu <azuciao@gmail.com>

```

```
$ npm info @azu/npm-github-package-example

@azu/npm-github-package-example@2.3.0 | MIT | deps: none | versions: 9
npm registry to GitHub Package Registry example.
https://github.com/azu/npm-github-package-example

dist
.tarball: https://npm.pkg.github.com/download/@azu/npm-github-package-example/2.3.0/3bdb8322c3344012bcf5ab5819f433fc1e2029ca5a9cf42e8580a2dd0086d9e1
.shasum:

dist-tags:
latest: 2.3.0

published over a year ago by undefined <undefined>
```

## Question

Is this bug of GitHub Package Registry?

I think that `registry="https://npm.pkg.github.com/org` should proxy to npm's `@org/*` package.
This feature is called Uplinks in verdaccio.

- https://verdaccio.org/docs/en/uplinks
- https://stackoverflow.com/questions/54543979/npmrc-multiple-registries-for-the-same-scope

It seem that yarnpkg registry support similar proxy feature.

GitHub Package Registry does not work.

```
$ npm info @azu/testtest --registry "https://npm.pkg.github.com/azu"
npm ERR! code E404
```

yarnpkg registry does work.

```
$ npm info @azu/testtest --registry "https://registry.yarnpkg.com"

@azu/testtest@1.0.0 | MIT | deps: none | versions: 2

dist
.tarball: https://registry.npmjs.org/@azu/testtest/-/testtest-1.0.0.tgz
.shasum: a8ed44b4e3ea61011fc257a238aa36306ef316f3
.integrity: sha512-UPyAXnx64pWO14oUGwJlTm1f1VAIMOWMKl5YlXCXETxfJSBxjHi0WR2sKk2JVls1CacLttmv0FwXXwFufNJvIg==
.unpackedSize: 230 B

maintainers:
- azu <azuciao@gmail.com>

dist-tags:
a1: 1.0.1      a: 1.0.0       latest: 1.0.0

published 6 months ago by azu <azuciao@gmail.com>
```

## Summary

I've tested variable patterns for combination registries.

### Pattern A

```
registry="https://npm.pkg.github.com/ORG"
```

### Pattern B

``` 
registry="https://registry.npmjs.org"
@ORG:registry="https://npm.pkg.github.com/ORG"
```

### Pattern C

``` .npmrc
registry="https://registry.npmjs.org"
@ORG:registry="https://npm.pkg.github.com"
```

Related

- [Solved: Github Package Registry scope conflict with proxy - GitHub Community Forum](https://github.community/t5/GitHub-Actions/Github-Package-Registry-scope-conflict-with-proxy/m-p/31925)

### Pattern D

``` .npmrc
registry=https://npm.pkg.github.com/ORG
@ORG:registry=https://registry.npmjs.org
```

### Results

| Pattern | non-scoped package | Npm @ORG/\* | GitHub @ORG/\* |
| ------- | ------------------ | ----------- | -------------- |
| A       | ok                 | ng          | ok             |
| B       | ok                 | ng          | ok             |
| C       | ok                 | ng          | ok             |
| D       | ok                 | ok          | ng             |