Context

This is a change for #8020 (comment). My full plan is:

1. Read the pnpm-workspace.yaml in @pnpm/config as suggested here
2. Pass the in-memory workspaceManifest to find-workspace-packages as an optional argument.

This PR allows 2 to be done in a follow-up PR:

• refactor: add WorkspaceManifest to @pnpm/config gluxon/pnpm#6

Changes

This PR adds a new workspaceManifest option. A test was added, but this new option is not yet used by other parts of pnpm.

Alternative

Alternatively we could "break" the find-workspace-packages utilities and force users of the @pnpm/workspace.find-packages to supply pnpm-workspace.yaml's contents.

One API change we could make is:

 export async function findWorkspacePackages (
   workspaceRoot: string,
+   patterns: string[] | WorkspaceManifest | undefined,
   opts?: FindWorkspacePackagesOptions
 ): Promise<Project[]>;

Or alternatively the WorkspaceManifest wouldn't be passed at all. Users of @pnpm/workspace.find-packages would pass workspaceManifest.packages as the patterns argument.

 export async function findWorkspacePackages (
   workspaceRoot: string,
+   patterns: string[],
   opts?: FindWorkspacePackagesOptions
 ): Promise<Project[]>;

Let me know if either of these alternatives are preferred.