library

In a sample2 directory, run

mkdir sample2 && cd sample2

dotnet new

Now let’s create a library app, run

dotnet new lib -n l1 -lang f#

the -n pass the name of the project, and create a subdirectory.

and open

code .

Because the project is in a subdirectory, the dotnet build fails because doesnt know what project to build. Is enough to pass the directory or the path of project file.

dotnet build l1

Same in code, in tasks.json, set "command": "dotnet build l1",

reference from a console app

as before, create a simple console app c1

dotnet new console -n c1 -lang f#

And now reference the l1 from c1

dotnet add c1 reference l1/l1.fsproj

Is now possibile to use the methods from l1 in c1 Add to main

    l1.Say.hello "Openfsharp!"

to run it:

• or dotnet run -p c1 from terminal
• or update the tasks.json and launch.json to correct c1 paths, for code

this is neeeded because dotnet build doesnt build all project in the subdirectories, but all project referenced from the initial one.

test with xunit

To add an unit test project, based on xUnit Library

dotnet new xunit -n l1.Tests -lang f#

And add the project reference to l1

dotnet add l1.Tests reference l1/l1.fsproj

Now let’s change the l1 to refactor and extract an helloMessage function

    let helloMessage name =
        sprintf "Hello %s" name

    let hello name =
        printfn "%s" (helloMessage name)

and test it in Tests.fs

[<Fact>]
let ``hello`` () =
    Assert.Equal("Hello openfsharp", (l1.Say.helloMessage "openfsharp conf"))

the test can be run with dotnet test l1.Tests

In vscode, configure the test task

• > Tasks: Configure Task Runner
• same as build task, but with:
  • group kind test instead of build
  • command: dotnet test l1.Tests

Now tests can be executed with

• > Tasks: Run Test Task

test with expecto

The dotnet new allow to import additinal templates. for example, let use expecto

First let’s import the template

dotnet new -i Expecto.Template::*

now the expecto template is installed (see dotnet new --list)

Templates                         Short Name       Language          Tags
-------------------------------------------------------------------------
Expecto .net core Template        expecto          F#                Test

to create a new project (-o is needed to specify output path)

dotnet new expecto -n l1.Test2 -o l1.Tests2 -lang f#

NOTE The expecto template use .net core 1, let’s change it to .net core 2

• remove FSharp.NET.Sdk, FSharp.Core references
• change tfm to <TargetFramework>netcoreapp2.0</TargetFramework>
• change Microsoft.DotNet.Watcher.Tools version to 2.0.0

more info in netcorecli-fsc wiki page 1.0 -> 2.0

And add the project reference to l1

dotnet add l1.Tests2 reference l1/l1.fsproj

and add a new test case

    testCase "helloMessage" <| fun _ ->
      Expect.equal (l1.Say.helloMessage "openfsharp") "Hello openfsharp conf" "These should equal"

and run it with dotnet run -p l1.Tests2.

Because is a normal console app, it’s possibile to debug it.

NOTE Ionide has also a support for expecto builtin, try the > Expecto:

pack

To create the nuget package from library, is possibile to use the dotnet pack command

dotnet pack l1 -c Release /p:Version=1.2.3

this will create a package

Successfully created package 'E:\wssf\sample2\l1\bin\Release\l1.1.2.3.nupkg'.

To specify other package metadata (like Version), is possibile to:

• pass it as command line, like /p:Version=1.2.3
• pass is as environment variable (so Version)
• or specify it in an msbuild property inside the like <Version>1.2.3</Version>

Others Authors, Summary, Description, PackageTags, etc

push

to push a package to a nuget feed, you can use dotnet nuget push

For example, to push to myget feed

RUN

dotnet nuget push l1/bin/Release/l1.1.2.3.nupkg -s https://www.myget.org/F/openfsharp-workshop/api/v2/package -k e89848f5-a549-4238-8016-24cbed33dfcc

to restore from a dev feed:

dotnet add package l1 --version 1.2.3 --source https://www.myget.org/F/openfsharp-workshop/api/v3/index.json