Run on the ARC public pools, via a nix-built test binary

.github/actions/arc_env/action.yml

@@ -0,0 +1,20 @@
+name: "ARC environment"
+runs:
+  using: "composite"
+  steps:
+    - name: Authenticate nix's github fetches
+      shell: bash
+      run: |
+        # Writing to GITHUB_ENV replaces, so preserve any existing NIX_CONFIG.
+        {
+          echo "NIX_CONFIG<<NIX_CONFIG_EOF"
+          if [[ -n "${NIX_CONFIG:-}" ]]; then echo "$NIX_CONFIG"; fi
+          echo "access-tokens = github.com=${{ github.token }}"
+          echo "NIX_CONFIG_EOF"
+        } >> "$GITHUB_ENV"
+
+    # Separate step: GITHUB_ENV only lands in the next one, and this eval needs the token.
+    - name: Set NIX_PATH from the flake's own nixpkgs
+      shell: bash
+      run: |
+        echo "NIX_PATH=nixpkgs=$(nix run .#nixpkgsPath)" >> "$GITHUB_ENV"

.github/workflows/ci.yml

@@ -7,83 +7,45 @@ on:
   workflow_dispatch:
 
 jobs:
-  stack:
-    name: stack / ghc ${{ matrix.ghc }}
-    runs-on: [self-hosted, Linux, desktop]
+  tests:
+    name: tests
+    runs-on: arc-public-medium
     strategy:
       fail-fast: false
-      # matrix:
-      #   ghc:
-      #   - "9.6.3"
 
     steps:
-    # - name: Install libraries
-    #   run: |
-    #     sudo apt update
-    #     sudo apt install -y libzmq5-dev libpcre3-dev
-
     - uses: actions/checkout@v4
 
-    # - uses: haskell/actions/setup@v1
-    #   name: Setup Haskell Stack
-    #   with:
-    #     ghc-version: ${{ matrix.ghc }}
-    #     stack-version: "latest"
-    #     enable-stack: true
-
-    # - uses: actions/cache@v4
-    #   name: Cache ~/.stack
-    #   with:
-    #     path: ~/.stack
-    #     key: ${{ runner.os }}-${{ matrix.ghc }}-stack
-
-    - name: Build
-      run: |
-        # stack build --system-ghc --test --bench --no-run-tests --no-run-benchmarks
-        export NIX_PATH="nixpkgs=$(nix run .#nixpkgsPath)"
-        echo "NIX_PATH: $NIX_PATH"
-        nix run .#stack -- build --nix --test --bench --no-run-tests --no-run-benchmarks
+    - uses: ./.github/actions/arc_env
 
-    - name: Test
+    - name: Run tests
       run: |
-        # stack test --system-ghc --test-arguments --print
-        export NIX_PATH="nixpkgs=$(nix run .#nixpkgsPath)"
-        echo "NIX_PATH: $NIX_PATH"
-        nix run .#stack -- test --nix --test-arguments --print
+        TESTS=$(nix build --no-link --print-out-paths .#tests)/bin/rust-notebook-language-server-test
+        "$TESTS" --print
 
   no-gmp:
-    runs-on: [self-hosted, Linux, desktop]
+    runs-on: arc-public-small
     strategy:
       fail-fast: false
     steps:
     - uses: actions/checkout@v4
 
-    # - uses: cachix/install-nix-action@v22
-    #   with:
-    #     nix_path: nixpkgs=channel:nixos-unstable
-    #     extra_nix_config: |
-    #       trusted-public-keys = hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
-    #       substituters = https://hydra.iohk.io https://cache.nixos.org/
+    - uses: ./.github/actions/arc_env
 
     - name: No GMP
       run: |
         nix run .#verify-no-gmp
 
   nix:
     name: Nix
-    runs-on: [self-hosted, Linux, desktop]
+    runs-on: arc-public-small
     strategy:
       fail-fast: false
 
     steps:
     - uses: actions/checkout@v4
 
-    # - uses: cachix/install-nix-action@v22
-    #   with:
-    #     nix_path: nixpkgs=channel:nixos-unstable
-    #     extra_nix_config: |
-    #       trusted-public-keys = hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
-    #       substituters = https://hydra.iohk.io https://cache.nixos.org/
+    - uses: ./.github/actions/arc_env
 
     - name: Build
       run: |

flake.nix

@@ -108,6 +108,8 @@
               }}
             '';
 
+            tests = flake.packages."rust-notebook-language-server:test:rust-notebook-language-server-test";
+
             nixpkgsPath = pkgs.writeShellScriptBin "nixpkgsPath.sh" "echo -n ${pkgs.path}";
           });