topological sorting of workspaces when executing commands.

[trusktr]

It would be nice if we had an option to avoid having to ensure that workspaces in the workspaces array are listed in order for cases like running a build step in all packages.

Currently, we must ensure they are in order, so that a dependency of a dependent package will be built before the dependent package get built when running a command like npm run build --workspaces.

With a new topologicalSort: true option, or similar, we could opt into new behavior that automatically sorts workspaces when running a command that uses --workspace or --workspaces based on the dependency graph, and executes the commands in the correct order.

Furthermore, having topological sort in place will provide the opportunity for the npm cli to be able to run processes of each package in parallel, like Lerna does. F.e. if A depends on B and C, but B and C do not depend on A or on each other, then npm run build --workspaces can run build for both B and C in parallel, then run build for A once both B and C complete.

[MylesBorins]

@trusktr if you would like to suggest new features to the CLI the best course of action is to open up an issue over at https://github.com/npm/rfcs