setup ci for jax-metal plugin

.github/workflows/metal_plugin_ci.yml

@@ -0,0 +1,42 @@
+# JAX-Metal plugin CI
+
+name: Jax-Metal CI
+on:
+  workflow_dispatch: # allows triggering the workflow run manually
+
+jobs:
+  jax-metal-plugin-test:
+
+    strategy:
+      fail-fast: false # don't cancel all jobs on failure
+      matrix:
+        jaxlib-version: ["plugin_latest"]
+    name: "Jax-Metal plugin test (jaxlib=${{ matrix.jaxlib-version }})"
+    runs-on: [self-hosted, macOS, ARM64]
+
+    steps:
+      - name: Get repo
+        uses: actions/checkout@v4
+        with:
+          path: jax
+      - name: Setup build and test enviroment
+        run: |
+          rm -rf ${GITHUB_WORKSPACE}/jax-metal-venv
+          python3 -m venv ${GITHUB_WORKSPACE}/jax-metal-venv
+          source  ${GITHUB_WORKSPACE}/jax-metal-venv/bin/activate
+          pip install -U pip numpy wheel
+          pip install jax-metal absl-py pytest
+          if [[ "${{ matrix.jaxlib-version }}" == "nightly" ]]; then
+            pip install --pre jaxlib \
+              -f https://storage.googleapis.com/jax-releases/jaxlib_nightly_releases.html
+          fi;
+          cd jax
+          pip install .
+      - name: Run test
+        run: |
+          source  ${GITHUB_WORKSPACE}/jax-metal-venv/bin/activate
+          export ENABLE_PJRT_COMPATIBILITY=1
+          cd jax
+          pytest tests/lax_metal_test.py
+
+

jax/_src/test_util.py

@@ -349,6 +349,8 @@ def supported_dtypes():
   elif device_under_test() == "iree":
     types = {np.bool_, np.int8, np.int16, np.int32, np.uint8, np.uint16,
              np.uint32, np.float32}
+  elif device_under_test() == "METAL":
+    types = {np.int32, np.uint32, np.float32}
   else:
     types = {np.bool_, np.int8, np.int16, np.int32, np.int64,
              np.uint8, np.uint16, np.uint32, np.uint64,
@@ -423,6 +425,8 @@ def _get_device_tags():
     device_tags = {device_under_test(), "rocm"}
   elif is_device_cuda():
     device_tags = {device_under_test(), "cuda"}
+  elif device_under_test() == "METAL":
+    device_tags = {device_under_test(), "gpu"}
   else:
     device_tags = {device_under_test()}
   return device_tags