dotnet tool install should return exit code 0 if tool is already installed

I’m trying to write a script that will install global tools if necessary. I would like to just run “dotnet tool install”, but this returns exit code 0 if the tool is already present, so I have to first execute dotnet tool list and grep the output.

Expected behavior

Calling dotnet tool install should no-op AND exit code 0 if the tool is already installed

Actual behavior

Running dotnet tool install twice fails scripts because the second time it runs it will exit code 0

PS> & dotnet tool install --tool-path "$(pwd)/.tools" sleet --version 2.3.25 --add-source https://api.nuget.org/v3/index.json
You can invoke the tool using the following command: sleet
Tool 'sleet' (version '2.3.25') was successfully installed.
PS> $lastexitcode
0
PS>  & dotnet tool install --tool-path "$(pwd)/.tools" sleet --version 2.3.25 --add-source https://api.nuget.org/v3/index.json
Tool 'sleet' is already installed.
PS>  $lastexitcode
1

The result of this is that I have write more complicate code like this:

if (& $dotnet tool list --tool-path "$PSScriptRoot/.tools" | Select-String "sleet") {
    Write-Host -f Yellow 'Skipping install of sleet. It''s already installed'
}
else {
    Invoke-Block { & $dotnet tool install --tool-path "$PSScriptRoot/.tools" sleet --version 2.3.25 --add-source https://api.nuget.org/v3/index.json }
}

Environment data

dotnet --info output:

.NET Core SDK (reflecting any global.json):
 Version:   2.1.300
 Commit:    adab45bf0c

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.17134
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\dev\aspnet\Universe20\.dotnet\sdk\2.1.300\

Host (useful for support):
  Version: 2.1.0
  Commit:  caa7b7e2ba

.NET Core SDKs installed:
  2.1.300 [C:\dev\aspnet\Universe20\.dotnet\sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.All 2.1.0 [C:\dev\aspnet\Universe20\.dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.0 [C:\dev\aspnet\Universe20\.dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.0 [C:\dev\aspnet\Universe20\.dotnet\shared\Microsoft.NETCore.App]

[tmds]

npm install returns 1 when it can’t change to the specified version. npm install returns 0 when the version is already installed.

npm install without a version specified will update to the latest version when the package is already installed.

This matches my expectations as a user.

[cottsak]

@KathleenDollard It’s not a “bad” choice. But IMO, it’s less than ideal. When scripting something it would be great to simply use dotnet install as an idempotent command meaning that it will implicitly “install” if not present, or return 0 if it’s already installed. It just makes life easier, and seems to be an established convention.