Fixes the metadata file name to avoid ambiguities (#6762)

Fixes #6761

## What's the problem this PR addresses?

By using `-` to separate the scope and name in `slugifyident`, the code
could result in a name collision between packages (eg., `@x-y/z` and
`@x/y-z`).

<!-- Describe the rationale of your PR. -->
<!-- Link all issues that it closes. (Closes/Resolves #xxxx.) -->

...

## How did you fix it?

This change uses `~` instead, which is valid in file names but not
package names.

...

## Checklist

<!--- Don't worry if you miss something, chores are automatically
tested. -->
<!--- This checklist exists to help you remember doing the chores when
you submit a PR. -->
<!--- Put an `x` in all the boxes that apply. -->
- [x] I have read the [Contributing
Guide](https://yarnpkg.com/advanced/contributing).

<!-- See
https://yarnpkg.com/advanced/contributing#preparing-your-pr-to-be-released
for more details. -->
<!-- Check with `yarn version check` and fix with `yarn version check
-i` -->
- [x] I have set the packages that need to be released for my changes to
be effective.

<!-- The "Testing chores" workflow validates that your PR follows our
guidelines. -->
<!-- If it doesn't pass, click on it to see details as to what your PR
might be missing. -->
- [x] I will check that all automated PR checks pass before the PR gets
reviewed.

---------

Co-authored-by: Maël Nison <nison.mael@gmail.com>

Author: MLoughry

.yarn/versions/dd3b3646.yml

@@ -0,0 +1,35 @@
+releases:
+  "@yarnpkg/core": patch
+  "@yarnpkg/plugin-npm": patch
+
+declined:
+  - "@yarnpkg/plugin-compat"
+  - "@yarnpkg/plugin-constraints"
+  - "@yarnpkg/plugin-dlx"
+  - "@yarnpkg/plugin-essentials"
+  - "@yarnpkg/plugin-exec"
+  - "@yarnpkg/plugin-file"
+  - "@yarnpkg/plugin-git"
+  - "@yarnpkg/plugin-github"
+  - "@yarnpkg/plugin-http"
+  - "@yarnpkg/plugin-init"
+  - "@yarnpkg/plugin-interactive-tools"
+  - "@yarnpkg/plugin-jsr"
+  - "@yarnpkg/plugin-link"
+  - "@yarnpkg/plugin-nm"
+  - "@yarnpkg/plugin-npm-cli"
+  - "@yarnpkg/plugin-pack"
+  - "@yarnpkg/plugin-patch"
+  - "@yarnpkg/plugin-pnp"
+  - "@yarnpkg/plugin-pnpm"
+  - "@yarnpkg/plugin-stage"
+  - "@yarnpkg/plugin-typescript"
+  - "@yarnpkg/plugin-version"
+  - "@yarnpkg/plugin-workspace-tools"
+  - "@yarnpkg/builder"
+  - "@yarnpkg/cli"
+  - "@yarnpkg/doctor"
+  - "@yarnpkg/extensions"
+  - "@yarnpkg/nm"
+  - "@yarnpkg/pnpify"
+  - "@yarnpkg/sdks"

packages/plugin-npm/sources/npmHttpUtils.ts

@@ -164,6 +164,14 @@ async function loadPackageMetadataInfoFromNetwork(identPath: PortablePath, ident
   });
 }
 
+function generateMetadataFileName(ident: Ident) {
+  if (ident.scope !== null) {
+    return `@${ident.scope}-${ident.name}-${ident.scope.length}`;
+  } else {
+    return ident.name;
+  }
+}
+
 /**
  * Caches and returns the package metadata for the given ident.
  *
@@ -177,7 +185,7 @@ export async function getPackageMetadata(ident: Ident, {cache, project, registry
   registry = normalizeRegistry(configuration, {ident, registry});
 
   const registryFolder = getRegistryFolder(configuration, registry);
-  const identPath = ppath.join(registryFolder, `${structUtils.slugifyIdent(ident)}.json`);
+  const identPath = ppath.join(registryFolder, `${generateMetadataFileName(ident)}.json`);
 
   let cached: CachedMetadata | null = null;