chore(ci): test gpu backend on ci (#75)

* chore(ci): test gpu backend on ci

Signed-off-by: Cocoa <[email protected]>

.github/workflows/ci.yml

@@ -76,6 +76,8 @@ jobs:
           - { otp: "25.3.2.15", elixir: "1.15.4" }
           - { otp: "25.3.2.15", elixir: "1.16.2", lint: true }
           - { otp: "25.3.2.15", elixir: "1.16.2", build: true }
+          - { otp: "25.3.2.15", elixir: "1.16.2", gpu: true }
+          - { otp: "25.3.2.15", elixir: "1.16.2", gpu: true, build: true }
     env:
       MIX_ENV: test
     steps:
@@ -142,7 +144,14 @@ jobs:
       - name: Run tests
         run: |
           export PATH="${{ steps.setup.outputs.path }}:${PATH}"
+          export EMLX_TEST_DEFAULT_GPU="${{ matrix.job.gpu }}"
+
           if [ "${{ matrix.job.build }}" = "true" ]; then
             export LIBMLX_BUILD=true
           fi
-          mix test --warnings-as-errors
+
+          if [ "${{ matrix.job.gpu }}" = "true" ]; then
+            find test -name "*_test.exs" -exec bash -c 'NAME={}; echo -e "\n\n----$NAME----\n"; mix test $NAME' \;
+          else
+            mix test --warnings-as-errors
+          fi

test/test_helper.exs

@@ -1,3 +1,16 @@
-Application.put_env(:nx, :default_backend, EMLX.Backend)
+backend =
+  if String.downcase(System.get_env("EMLX_TEST_DEFAULT_GPU", "false")) in [
+       "1",
+       "true",
+       "yes",
+       "t",
+       "y"
+     ] do
+    {EMLX.Backend, device: :gpu}
+  else
+    EMLX.Backend
+  end
+
+Application.put_env(:nx, :default_backend, backend)
 
 ExUnit.start()