Clojure.MSBuild 0.0.7

Clojure.MSBuild

MSBuild integration for ClojureCLR. Build, test, and run Clojure on .NET with standard dotnet commands. No non-dotnet tools needed.

dotnet build AOT-compiles your namespaces and produces a standalone assembly whose entry point is a gen-class Main calling your -main. No C# in your project, no .cljr files needed at runtime.

Requirements

• .NET 11.0 SDK, 11.0.100-rc.1 or later
• Clojure CLR 1.12.6 or later

Quick Start

1. Create a project

dotnet new console -n MyApp
cd MyApp
rm Program.cs

The project must not contain C# sources: dotnet build replaces the project assembly with the compiled Clojure entry point (see How the build works).

2. Add packages

dotnet add package Clojure.MSBuild
dotnet add package Clojure --version 1.12.6

3. Update your .csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net11.0</TargetFramework>
    <EnablePreviewFeatures>true</EnablePreviewFeatures>
    <ClojureMainNamespace>app</ClojureMainNamespace>
    <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Clojure.MSBuild" Version="0.0.7" />
    <PackageReference Include="Clojure" Version="1.12.6" />
  </ItemGroup>

  <ItemGroup>
    <Content Include="src/**/*.cljr" CopyToOutputDirectory="PreserveNewest" />
  </ItemGroup>

</Project>

4. Write your app

Create src/app.cljr:

(ns app)

(defn -main [& args]
  (println "Hello from ClojureCLR!"))

5. Build and run it

dotnet build
dotnet run

dotnet build compiles app (and every namespace it requires) to .dll files next to MyApp.dll, and MyApp.dll itself is the compiled entry point: a class named after the assembly with a static Main generated by gen-class that calls app/-main. dotnet MyApp.dll, ./MyApp and dotnet publish all use it.

How the build works

1. The SDK compiles a small generated C# host into MyApp.dll.
2. After Build, the ClojureBuild target runs that host to AOT-compile clojure.msbuild.entry (generated, contains (:gen-class :name MyApp :main true)), your main namespace, its dependencies and ClojureNamespacesToCompile.
3. The compiled *.cljr.dll files are copied to the output directory and the compiled entry point replaces MyApp.dll.

Because the project assembly is replaced, the project cannot contain C# sources of its own. Put C# in a class library and reference it, or set ClojureEntryPoint to csharp to keep a generated C# Main as the entry point (Clojure is still AOT-compiled). Either way --clj-mode tooling (REPL, nREPL, tests, scripts) is handled by the same entry point.

Clojure Git Dependencies

Add Clojure libraries from git directly in your .csproj — no deps.edn needed:

<ItemGroup>
  
  <PackageReference Include="Clojure" Version="1.12.6" />
  <PackageReference Include="Microsoft.Data.Sqlite" Version="11.0.0-rc.1.26425.128" />

  
  <ClojureGitDep Include="io.github.clojure/clr.data.json" Tag="v2.5.1" Sha="f84cb88" />
  <ClojureGitDep Include="com.github.seancorfield/honeysql" Tag="v2.7.1368" Sha="b8332fc" />
</ItemGroup>

Repos are cloned to ~/.gitlibs (cached, compatible with cljr) when the build and tooling run; the compiled application contains the dependency namespaces and does not need git at runtime. Supports io.github, com.github, io.gitlab, and ht.sr prefixes for auto URL resolution. You can also specify a full URL:

<ClojureGitDep Include="my/lib" Tag="v1.0" Sha="abc123" Url="https://example.com/repo.git" />

A deps.edn file is also supported if you prefer the Clojure convention. Both sources merge.

Testing

Add the test adapter package:

dotnet add package Clojure.MSBuild.TestAdapter
dotnet add package Microsoft.NET.Test.Sdk

Add test content to your .csproj:

<Content Include="test/**/*.cljr" CopyToOutputDirectory="PreserveNewest" />

Create test files with the _test.cljr suffix in a test/ directory:

(ns app-test
  (:require [clojure.test :refer [deftest is testing]]))

(deftest test-addition
  (testing "math works"
    (is (= 4 (+ 2 2)))))

Run tests:

dotnet test

REPL

dotnet msbuild /t:clj-repl

nREPL

dotnet add package clojure.tools.nrepl --prerelease
dotnet msbuild /t:clj-nrepl

Connects on port 1667. Use Calva, CIDER, or any nREPL client.

Run a Script

dotnet msbuild /t:clj-run -p:File=path/to/script.clj

AOT Compilation

The main namespace and everything it requires are compiled on every build. To compile additional namespaces (for example ones with their own gen-class), list them:

<PropertyGroup>
  <ClojureNamespacesToCompile>my.lib;my.utils</ClojureNamespacesToCompile>
</PropertyGroup>

Note: (t/await (f ...)) on a call to a Clojure ^:async function needs the call's static Task<T> type. Tag the call site, or attach the tag to the var:

(alter-meta! #'execute! assoc :tag (symbol "System.Threading.Tasks.Task`1[System.Object]"))

Configuration

Examples

• examples/minimal-api — ASP.NET web API with HoneySQL, async ADO.NET, integration tests
• examples/csharp-interop — Bidirectional C#/Clojure interop in one project (ClojureEntryPoint=csharp)

License

MIT