It should return error when run dotnet tool list using non-exist tool path

Steps to reproduce

Run dotnet tool list --tool-path “~/non-exist-path”

Expected behavior

It should return error path

Actual behavior

The output shows the table header with package id, version, and commands. 

Environment data

dotnet --info output: .NET Core SDK (reflecting any global.json): Version: 2.1.300-preview2-008407 Commit: 5a5e35c Runtime Environment: OS Name: ubuntu OS Version: 16.04 OS Platform: Linux RID: ubuntu.16.04-x64 Base Path: /usr/share/dotnet/sdk/2.1.300-preview2-008407/ Host (useful for support): Version: 2.1.0-preview2-26326-03 Commit: 01c8d79c6a .NET Core SDKs installed: 2.1.300-preview2-008407 [/usr/share/dotnet/sdk] .NET Core runtimes installed: Microsoft.AspNetCore.All 2.1.0-preview2-30478 [/usr/share/dotnet/shared/Microsoft.AspNetCore.All] Microsoft.AspNetCore.App 2.1.0-preview2-30478 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App] Microsoft.NETCore.App 2.1.0-preview2-26326-03 [/usr/share/dotnet/shared/Microsoft.NETCore.App] To install additional .NET Core runtimes or SDKs: https://aka.ms/dotnet-download

[peterhuene]

I’m in agreement that we should probably throw GracefulException if the given path doesn’t exist. For example, if I mistyped the path, I’d expect the tool to let me know rather than just showing empty, as there’s no way to know the difference between a bad path or an empty tools directory.

For install, there shouldn’t be an error because it creates the directory.

For uninstall, it will error because it can’t find the tool package to uninstall (although, it should probably have the same error as list).

[KathleenDollard]

LGTM