Tool helper utilities should allow for dotnet cli, global and local tools

[SteveGilham]

Description

Some traditional .net framework tools now offer dotnet CLI or global tool variants (and with .net core 3.0, those global tools can be installed as local ones), but where Fake offers helper classes, those still assume traditional framework .exe files.

Repro steps

In a project, create a .config/dotnet-tools.json like

{
  "version": 1,
  "isRoot": true,
  "tools": {
    "dotnet-reportgenerator-globaltool": {
      "version": "4.2.20",
      "commands": [
        "reportgenerator"
      ]
    }
  }
}

With .net core 3.0, run dotnet tool restore

At the command line, you can run dotnet reportgenerator, but the Fake.Testing.ReportGenerator.ReportGeneratorParams type has no way to accept that.

Expected behavior

An indicator type (probably in a core module) like
type ToolType = DotNet of string | Global | Framework

and an extra .ToolType field in the Params type, defaulting to ToolType.Framework, but when overridden would ignore the .ExePath and execute dotnet [toolname] or [toolname] for ToolType.DotNet (cli and local tool variants, with the string there to allow for possible tool name differences) and ToolType.Global respectively.

Consideration might be given to deprecating .ExePath and defining ... | Framework of String instead, with any non null-or-empty string overriding .ExePath

Actual behavior/Known workarounds

I need to use a raw command executor and roll my own arguments as "dotnet reportgenerator" isn't a valid .ExePath, and the global reportgenerator would be mono-ified on non-Windows platforms

Related information

• Operating system -- any
• Branch -- as released
• .NET Runtime, CoreCLR or Mono Version
• Indications of severity -- mainly an annoyance
• Version of FAKE (4.X, 5.X) -- 5.16.1
• (if performance issue) Performance information, links to performance testing scripts -- N/A

[TheAngryByrd]

This is definitely an issue now that paket can be a local tool.

[matthid]

Will be available in the next release via #2399:

• A low level helper CreateProcess.withToolType
• A ToolType parameter for reportgenerator and paket